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Current crop stress resistance research suggests that the prominent stimulants nanoselenium (NSe) and melatonin (MT) might improve tea safety, quality, and stress resistance induced by the widely used nonselective herbicide glufosinate (GLU). Their biofortification effects on tea growth, antioxidant activity, and secondary metabolism pathways response to GLU remain unclear. Here, NSe, MT, and their combination NSe-MT effectively reduced 26.6-50.9% GLU and its metabolites in tea seedlings, balanced the photosystem, enhanced antioxidant defenses, and optimized reactive oxygen species scavenging mechanisms. Further, GLU-induced inhibition of glutamine synthetase (11.2-34.0%), ammonium toxicity (55.0-64.7%), and nitrogen metabolism disorders were alleviated. Stimulants exhibited different preferences in the accumulation of l-theanine (8.4-47%), gamma-aminobutyric acid (10.3-41.7%), and catechins (13.1-73.1%, excluding ECG), thereby influencing tea quality. Transcriptomic and metabolomic analyses validated that NSe-MT had a more pronounced impact on tender tea leaves than individual stimulant treatments. All stimulants reduced GLU-induced excessive jasmonic acid (29.8-50.5%) production and signaling responses, revealing their significance in crop physiological activities under herbicide or nitrogen stress. The reduction in aromatic amino acids helped mitigate GLU's interference with phenylpropanoid biosynthesis, leading to inhibited lignin production but enhanced nutritional flavonoid levels, such as catechins. NSe and NSe-MT demonstrated promising potential as herbicide safeners. These findings provided insights into GLU detoxification mechanisms in other nontarget crops as well.

Although ozone (O 3 ) pollution affects plant growth and monoterpene (MT) emissions, the responses of MT emission rates to elevated O 3 and the related mechanisms are not entirely understood. To gain an insight into these effects and mechanisms, we evaluated physiological (leaf MT synthesis ability, including precursor availability and enzyme kinetics) and physicochemical limiting factors (e.g. leaf thickness of the lower and upper epidermis, palisade and spongy tissue, and size of resin ducts and stomatal aperture) affecting MT emissions simultaneously from two broad-leaved and two coniferous species after one growing season of field experiment. The effects of elevated O 3 on MT emissions and the related mechanisms differed between plant functional types. Specifically, long-term moderate O 3 exposure significantly reduced MT emissions in broad-leaved species, primarily attributed to a systematic decrease in MT synthesis ability, including reductions in all MT precursors, geranyl diphosphate content, and MT synthase protein levels. In contrast, the same O 3 exposure significantly enhanced MT emissions in coniferous species. However, the change in MT emissions in coniferous species was not due to modifications in leaf MT synthesis ability but rather because of alterations in leaf anatomical structure characteristics, particularly the size of resin ducts and stomatal aperture. These findings provide an important understanding of the mechanisms driving MT emissions from different tree functional groups and can enlighten the estimation of MT emissions in the context of O 3 pollution scenarios as well as the development of MT emission algorithms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The impact of climate change on agricultural production is apparent due to declining irrigation water availability vis-à-vis rising drought stress, particularly affecting summer crops. Growing evidence suggests that zinc (Zn) supplementation may serve as a potential drought stress management strategy in agriculture. Field studies were conducted using soybean (Glycine max var. Saba) as a model crop to test whether foliar application of zinc oxide nanoparticles (ZnO-NPs) or conventional Zn fertilizer (ZnSO 4 ) would mitigate drought-related water stress and improve soybean yield. Each fertilizer was foliar applied twice at a two-week interval during the flowering stage. Experiments were concurrently conducted under non-drought conditions (70% field capacity) for comparison. Results showed drought significantly reduced relative water content, chlorophyll-a, and chlorophyll-b in untreated control plants by 35.7%, 47.7%, and 41.4%, respectively, compared to non-drought conditions (p < 0.05). Under drought conditions, ZnO-NPs (200 mg Zn/L) led to 33.1% and 20.7% increase in chlorophyll-a and chlorophyll-b levels, respectively, compared to ZnSO 4 at 400 mg Zn/L. Likewise, catalase, peroxidase and superoxide dismutase activities increased by 62.6%, 39.5% and 28.5%, respectively, with ZnO-NPs (200 mg Zn/L) under drought compared to non-drought conditions. Proline was significantly increased under drought but was remarkably suppressed (~ 54% lower) with ZnO-NPs (200 mg Zn/L) treatment. More importantly, the highest seed yield was observed with ZnO-NPs (200 mg Zn/L) treatment under drought (39% higher than untreated control) and non-drought (79.4% higher than control) conditions. Overall, the findings suggest that ZnO-NPs could promote seed yield in soybean under drought stress via increased antioxidant activities, increased relative water content, decreased stress-related proline content, and increased photosynthetic pigments. It is recommended that foliar application of 200 mg Zn/L as ZnO-NPs could serve as an effective drought stress management strategy to improve soybean yield., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Cadmium (Cd) can harm the yield and quality of vegetables, threatening food safety. Essential microelements such as iron are crucial for plant growth and can help alleviate heavy metal stress. Recently, nanoparticles have been studied as eco-friendly solutions for mitigating heavy metal stress in plants. In the present study, iron nanoparticles (FeNPs) at 0, 100, and 300 mg/L were applied as soil drenches and foliar sprays to tomato plants under cadmium stress. A comparison was made between the application methods of FeNPs by evaluating the growth parameters of tomato plants, including shoot length (SL), root length (RL), number of branches (NB), number of leaves per plant (NL), and leaf area (LA), as well as by assessing biochemical and antioxidant enzyme parameters. In the Cd stress treatment, the protein content decreased by 24.71%, and the phenolic and flavonoid content of the tomato plants also decreased due to cadmium stress, with levels decreasing from 16.07 to 6.9 µg and from 0.36 to 0.16 µg, respectively. Compared with the soil drench, 100 mg/L FeNPs significantly improved the parameters of Cd-stressed plants when used as a foliar spray, leading to increases in shoot length, root length, fruit weight, number of fruits, number of leaves, and number of branches by 42%, 66%, 24%, 66%, 173%, and 45%, respectively. Tomato plants treated with this spray presented increased carotenoid and lycopene contents. FeNP foliar spray also reduced Cd accumulation in plant tissues. This technique shows promise in alleviating Cd stress in vulnerable vegetable plants such as tomatoes., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethical approval and consent to participate We declare that the manuscript reporting studies do not involve any human participants, human data or human tissues. So, it is not applicable. Our experiment follows with the relevant institutional, national, and international guidelines and legislation., (© 2024. The Author(s).)

Nanotechnology represents a burgeoning field of science that enables advanced research across various domains. In recent years, there has been a notable increase in the utilization of silver nanoparticles (AgNPs) for diverse agricultural and industrial applications. Similarly, copper nanoparticles (CuNPs) have significant attention in agriculture due to their cost-effectiveness and practicality. This study aimed to investigate the potential impact of silver and copper nanoparticles on enhancing both the yield and quality of Brassica napus L. cultivar CON-1. The combined foliar application of green synthesized silver and copper nanoparticles at varying concentrations (0, 5, 10, 15, 20, 25, 30, and 35 mg/L) resulted in notable improvements in the growth, yield and quality of Brassica napus L. compared to untreated plants. Particularly, the concentration of 25 mg/L for both silver and copper nanoparticles demonstrated superior outcomes in terms of plant height, number of primary and secondary branches/plant, number of siliques /plant, number of seeds/silique, siliqua length, 1000-seed weight, biological yield/plant, seed yield/plant, oil yield/plant, and harvest index. Furthermore, the nanoparticles effectively reduced the accumulation of erucic acid in the oil, thereby enhancing the overall oil quality of canola. In summary, the application of silver and copper nanoparticles shows promising potential in improving the productivity and quality of Brassica napus L., highlighting their role as beneficial agricultural additives in modern farming practices., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

The effects of foliar application of sodium nitroprusside (SNP), magnesium sulfate (MgSO 4 ) and magnesium oxide nanoparticles (MgO-NPs) on the growth, physiology, and gas exchange parameters of two varieties of spinach (Spinacia oleracea L.) under cadmium (Cd) stress were examined. The experiment was arranged in a completely randomized design with 72 pots. Two varieties of S. oleracea (Desi Palak & Lahori Palak) were used. Two concentrations of Cd (0 µM and 150 µM) in the form of cadmium chloride (CdCl 2 ) were used. Two levels of SNP (0 ppm and 100 ppm) and two levels for each form of Mg i.e. MgSO 4 and MgO-NPs (0 and 200 ppm) were foliar sprayed on plants in control and Cd stress. Both varieties behaved similarly under Cd stress and caused reductions in growth, physiology, gas exchange, water content parameters and inorganic ion uptake. However, the biochemical parameters like relative membrane permeability (RMP), malondialdehyde (MDA), and hydrogen peroxide (H 2 O 2 ) contents were increased. However, all foliar spray treatments increased growth, physiological and gas exchange parameters, water content and inorganic ion uptake. However, this reduced the MDA, RMP, and H 2 O 2 contents. Desi Palak showed the more positive results under foliar application of MgO-NPs. However, Lahori palak showed more positive results under the SNP + MgO-NP treatment. It is concluded that foliar application of SNP, MgSO 4 and MgO-NPs could be an innovative approach to alleviated the heavy metals (Cd) toxicity in crop plants., (© 2024. The Author(s).)

Introduction and Objectives: Since the use of a bio stimulant should provide a response to a problem that depends on the production system implemented (crops, plant model, soil, climate, the farmer's practices…), the agricultural sector is facing concomitant challenges of choosing the best bio stimulant that suits their needs. Thus, understanding bio stimulant-plant interactions, at molecular level, using metabolomics approaches is a prerequisite, for the development of a bio stimulant, leading to an effective exploration and application of formulations in agriculture. AGRO-K®, is commercialized as a plant-based bio stimulant that improve vigor and enhance resistance to lodging in cereal crops. A recent previous untargeted metabolomics study has demonstrated the ability of this bio stimulant to improve wheat resistance to lodging, in real open-field conditions. However, the reproducibility of the impact of this bio stimulant in other filed crops is not yet investigated., Methods: Therefore, the present study aimed to assess the changes in primary and secondary metabolites in the roots, stems, and leaves of fiber flax (Linum usitatissimum L), treated with the bio stimulant, using NMR and LC-MS-based untargeted metabolomics approach., Results and Conclusions: In addition to the previous result conducted in wheat, the present analysis seemed to show that this bio stimulant led to a similar pathway enhancement in flax. The pathways which seem to be reproducibly impacted are hydroxycinnamic acid amides (HCAAs), phenylpropanoids and flavonoids. Impacting these pathways enhance root growth and elongation and cell wall lignification, which can aid in preventing crop lodging. These results confirm that HCAAs, flavonoids, and phenylpropanoids could serve as signatory biomarkers of the impact of AGRO-K® on improving lodging resistance across various plant species., (© 2024. The Author(s).)

Fimbristylis complanata is an aquatic halophytic sedge that thrives in salt-affected land, marshes, and water channels. Two ecotypes (HR-Rasool headworks ECe 19.45; SH- Sahianwala 47.49 dS m -1 ) of F. complanata were collected from two salt-affected wetlands of Punjab, Pakistan. Five rhizomes of each ecotype were grown in plastic pots in the Botanical garden research area and treated with three intensities of salt [0 mM (control), 200 mM (moderate), 400 mM (high) NaCl for three durations (0, 15 and 30 days). The pots were arranged using a completely randomized block design (CRD) with three replications. After each duration, sampling was done. The HR ecotype optimally performed better under moderate salt incubation and moderate to higher salt exposure. This ecotype had improved growth traits, including shoot fresh weight (SFW), shoot dry weight (SDW), leaf area (LA), root length (RL), leaf mass fraction (LMF), relative growth rate (RGR), and unit leaf area (ULA) at higher NaCl (400 mM) in comparison with control NaCl (0 mM). This improvement in growth occurs due to the accumulation of photosynthetic pigments, better photosynthesis, and water use efficiency (A/E). The leaf microstructure increased in HR ecotype as midrib (MrT), leaf blade (LTh), bulliform cells (BTh), and cortical cells (CcT) thicknesses to prevent water loss under salinity, increase aerenchymatous area (ArA) for efficient gas movements at moderate salt levels and less exposure time concerning absolute control (0 mM NaCl). The SH ecotype affirmed more tolerance to salt by securing higher biomass (SFW, SDW), increased growth traits (LA, RL, LMF, ULA), photosynthetic pigments (Chl a, b, Car), and maximum photosynthetic performance at high salt regimes and prolonged duration in comparison to control (0 mM NaCl). Additionally, increased MrT, LTh, BTh, ECA, abaxial and adaxial stomatal area, and density, broadened metaxylem and phloem area, large aerenchyma, more cortical cell thickness under moderate to high salt regimes under moderate to high salt levels and time. Overall, changes in morpho-physiological traits and leaf microstructures in both ecotypes are linked to salt tolerance under temporal salt regimes. Our findings suggest that both ecotypes of F. complanata can potentially rehabilitate the salt-affected wetlands., (© 2024. The Author(s).)

Melatonin is a potentially active signaling molecule and plays a crucial role in regulating the growth and development of plants under stress conditions, alleviating oxidative damage, enhancing antioxidant defence mechanisms and regulating ion homeostasis. This study examined the effects of exogenous melatonin application on leaf biomass, ion concentrations, betalains, phenolic acid and endogenous melatonin contents comparing red beet (Beta vulgaris L. 'Ruby Queen' and 'Scarlet Supreme') and white beet ('Rodeo' and 'Ansa') cultivars under increasing salinity levels of 50, 150, and 250 mM NaCl. Exogenous melatonin increased salinity-induced reductions in fresh and dry weights and osmotic potential in leaves. Na + concentrations rose significantly with increasing salinity, but cultivar-specific decreases were observed in K + and Ca 2+ concentrations. Additionally, melatonin application improved betalain, betanin and neobetanin contents induced by salt stress. Furthermore, melatonin application caused salt stress and cultivar-specific changes in phenolic acid contents e.g., ferulic acid, sinapic acid, or m-coumaric acid, in soluble free, ester- and glycoside-conjugated and cell wall-bound forms. In addition, antioxidant enzyme activities and compound contents increased significantly in the beets and were subsequently lowered in a cultivar-specific manner by salt stress + melatonin treatment. The current findings indicate that exogenous melatonin improved plant stress tolerance suppressing reactive oxygen species levels, increasing the antioxidant enzyme activities and compound contents and reducing the levels of Na + , maintaining an ionic homeostasis in the selected red and white sugar beet cultivars. It appears that melatonin application may help improve cultivar-specific salt tolerance by enhancing ion homeostasis and betalain and phenolic acid production levels in beets., (© 2024 Scandinavian Plant Physiology Society.)

Although plant-derived smoke solutions (SSs) have exhibited growth-promoting properties in various plant species, their potential role in mitigating heavy metal stress, specifically in grapevines, has remained unexplored and unreported. This knowledge gap prompted the present study to evaluate the efficacy of foliar application of SSs derived from vineyard pruning waste at concentrations of 0%, 0.5%, 1%, and 2% in mitigating Cadmium (Cd) phytotoxicity in grape saplings. In our study, cadmium stress was induced by applying 10 mg/kg CdCl 2 to the root area of the saplings, in conjunction with fertilizers. Our findings showed that exposure to Cd toxicity impeded the growth of grapevine saplings, adversely affecting shoot and root length, as well as fresh weight. Furthermore, it resulted in a reduction in chlorophyll content, stomatal conductance, and leaf water content while significantly increasing membrane damage and lipid peroxidation. Notably, the application of 0.5% SS enhanced grapevine sapling growth and alleviated Cd stress-induced damage by more effectively regulating physiological and biochemical responses compared to the control and other concentrations. Based on our results, under Cd stress conditions, the application of 0.5% SS effectively increased chlorophyll content, relative water content (RWC), stomatal conductance (1.79 mmol.m -2 .sn -1 ), and total phenolic content (1.89 mg.g -1 ), whereas it significantly reduced malondialdehyde (MDA) levels and membrane damage (1.35 nmol.g -1 ). Additionally, it significantly elevated the activities of antioxidant enzymes, including superoxide dismutase (SOD) (2.16 U.mg -1 ), catalase (CAT) (1.55 U.mg -1 ), and ascorbate peroxidase (APX) (3.03 U.mg -1 ). The study demonstrated that plant-derived SS mitigates Cd stress in grapevines by enhancing antioxidative defence mechanisms., (© 2024 Scandinavian Plant Physiology Society.)

Salt stress severely affects the growth and yield of apples (Malus domestica Borkh). Although salt-tolerant genes have been extensively studied, documentation on the role of the ATP-dependent phosphofructokinase gene MdPFK5 in salt stress is limited. This study conducted an evolutionary tree and three-dimensional structure analysis of the PFK gene family in Arabidopsis thaliana and MdPFK (MD01G1037400), revealing a close phylogenetic relationship between MdPFK (MD01G1037400) and AtPFK5. Given the similarity in their protein tertiary structures, MdPFK was designated as MdPFK5, suggesting functional similarities with AtPFK5. Further investigation revealed elevated expression levels of MdPFK5 in apple leaves and flowers, particularly showing significant upregulation 120 days after blooming and differential expression beginning at 3 hours of salt stress. Overexpression of MdPFPK5 conferred salt tolerance in both apple calli and transgenic lines of Arabidopsis thaliana. Moreover, NaCl treatment promoted soluble sugar accumulation in apple calli and transgenic lines of Arabidopsis thaliana overexpressing MdPFK5. This study provides new insights into the salt tolerance function of MdPFK5., (© 2024 Scandinavian Plant Physiology Society.)

The unregulated use and improper management of herbicides can cause negative effects on non-target species and promote changes in biological communities. Therefore, the current study is aimed at understanding morphoanatomical responses and effects on seedling development induced by the herbicides glyphosate and saflufenacil in Enterolobium contortisiliquum, a non-target tropical species. The plants were cultivated in a greenhouse and subjected to herbicides at doses of 0, 160, 480, and 1440 g a.e ha -1 for glyphosate, and 0, 25, 50, and 100 g a.i ha -1 for saflufenacil. We conducted visual and morphological assessments over 90 days post-application. Leaf samples were collected 12 days after the application for anatomical analysis, and we also performed a micromorphometric analysis of the leaf tissues. Biomarkers of phytotoxicity were identified in plants exposed to both herbicides, even at the lowest doses, including in leaves without visual symptoms. The main morphological alterations were the decrease in growth, stem diameter, and dry mass. Furthermore, the leaves and stems visually exhibited chlorosis and necrosis. Both herbicides triggered anatomical modifications such as significant changes (p < 0.05) in the thickness of leaf tissues, hypertrophy, cell collapse, and changes in epicuticular waxes. However, the alterations induced by glyphosate were more widespread compared to saflufenacil, encompassing alterations in the root system. We confirmed that the different mechanisms of action of each herbicide and the existence of an underground reserve system in this species are intrinsically linked to the morphological and developmental responses described. Our findings suggest that E. contortisiliquum could be a potential bioindicator species for these herbicides in the environment, even at concentrations lower than those typically recommended for field application., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Foxtail millet (Setaria italica (L.) P. Beauv.) is an environmentally friendly crop that meets the current requirements of international food security and is widely accepted as a photosynthesis research model. However, whether exogenous sucrose treatment has a positive effect on foxtail millet growth remains unknown. Here, we employed physiological and molecular approaches to identify photosynthesis and source capacity associated with exogenous sucrose during the growth of Jingu 21 seedlings. RNA-seq analysis showed that some differentially expressed genes (DEGs) related to photosynthesis and carotenoid biosynthesis were induced by exogenous sucrose and that most of these genes were up-regulated. An increase in gas exchange parameters, chlorophyll content, and chlorophyll fluorescence of Jingu 21 was noted after exogenous sucrose addition. Furthermore, exogenous sucrose up-regulated genes encoding sucrose and hexose transporters and enhanced starch and sucrose metabolism. More DEGs were up-regulated by sucrose, the nonstructural carbohydrate (NSC) content in the leaves increased and energy metabolism and sucrose loading subsequently improved, ultimately enhancing photosynthesis under normal and dark conditions. Further analysis revealed that WRKYs, ERFs, HY5, RAP2, and ABI5 could be key transcription factors involved in growth regulation. These results indicate that exogenous sucrose affects the normal photosynthetic performance of foxtail millet by increasing NSC transport and loading. They improve our understanding of the molecular mechanisms of the effects of exogenous sucrose on photosynthesis in foxtail millet, providing an effective measure to enhance source-sink relationships and improve yield., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Sustainable agriculture has become prime importance to feed growing population. To achieve this goal application of exogenous hormones and signaling molecules are gaining important. In this context, we have investigated potential of ethylene (25 μM ethephon; donor) and H 2 S (10 μM NaHS; donor) in mitigating hexavalent chromium [Cr (VI), 50 μM] toxicity in two pulse seedlings: black bean and mung bean. Cr(VI) declined growth and gas exchange parameters (photosynthetic rate, stomatal conductance, sub cellular CO 2 concentration, and transpiration level) which was accompanied by intracellular accumulation of Cr in both pulse crops and the damaging effect was greater in mung bean seedlings. The suppression in the growth and related parameters was occurred due to higher buildup of oxidative stress markers; O 2 • ‾, H 2 O 2 , lipid peroxidation (as malondialdehyde, MDA equivalents) and membrane injury in leaf and root of both pulse crops. Cr induced disturbance in AsA-GSH cycle (reduction in the activity of glutathione reductase, ascorbate peroxidase, monodehydroascorbate reductase and dehydroascorbate reductase, and the amount of ASA and GSH) could be one of the reasons for greater accumulation of H 2 O 2 . Further, exogenous application of ethylene and H 2 S significantly ameliorated Cr toxicity on growth and photosynthetic activity by significantly lowering the intracellular Cr accumulation and oxidative biomarkers, and also by strengthening the activity of AsA-GSH cycle. The exogenous application of biosynthesis inhibitors of ethylene (AVG) and H 2 S (PAG) caused greater damaging effect on these parameters due to more accumulation of Cr(VI), thereby suggesting that the endogenous levels of these regulators are critical for Cr(VI) tolerance. Interestingly, ET did not rescue adverse effects of Cr(VI) in absence of endogenous H 2 S, while H 2 S could do so even without endogenous ethylene, suggesting that H 2 S played downstream signaling to ethylene in regulating Cr(VI) toxicity. Hence, being cheap and easily available theses growth regulators may be considered for sustainable agriculture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

The effects of silver nanoparticles (AgNPs), both alone and in combination with mineral nutrients, on the growth and photosynthesis of Solanum lycopersicum plants during ontogeny were studied. The experiment involved weekly applications of 10 μmol of AgNPs for 15 weeks in a greenhouse over a summer period. A comprehensive characterization of the AgNPs was performed via TEM, ESI/EELS, and zeta potential measurements before and throughout the experiment. The activity of PSII, stomatal conductivity, photosynthesis, transpiration and respiration rates were measured, and the photosynthetic pigments, chloroplast ultrastructure, and dry and fresh masses of leaves, roots, and fruits were assessed. The results indicated that combining AgNPs with mineral nutrients increased PSII activity and the photosynthesis rate and altered the chloroplast ultrastructure. However, the use of mineral nutrients or AgNPs alone did not induce these changes. Atomic absorption spectrometry detected AgNPs in all the plant organs except the fruits. The highest fruit yield was associated with Veni Prisma®, a commercial product containing colloidal silver, which also caused desynchronized fruit maturation. This study hypothesizes that the synergistic effect of AgNPs and mineral nutrients enhances silver accumulation in chloroplasts, improving light utilization and photosynthetic efficiency, particularly under low light, thus increasing fruit quantity and dry mass. Conversely, long-term use of AgNPs alone was accompanied by silver accumulation outside the chloroplasts and did not lead to increased photosynthesis or an increase in fresh fruit mass., Competing Interests: Declaration of competing interest The authors Leonid Kulkov, Roman Arkhipov, Anna Abramova, Mikhail Vereshchagin, Alexander Voronkov, Lyudmila Khalilova, Alexander Kartashov, Ivan Tarakanov, Vladimir Kreslavski, Vladimir Kuznetsov, Pavel Pashkovskiy, Suleyman I. Allakhverdiev declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in the article “Long-term effects of silver nanoparticles and mineral nutrition components on the photosynthetic processes, chloroplast ultrastructure and productivity of Solanum lycopersicum plants”. All authors have approved the manuscript and agree with its submission to Journal of Photochemistry and Photobiology B: Biology. All Authors listed have contributed significantly to the work and agree to be in the author list. We confirm that neither the manuscript nor any parts of its content are currently under consideration or published in another journal. We wish to confirm that there are no known conflicts of interest associated with this publication. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Sulfur is an essential nutrient for various physiological processes, including protein synthesis and enzyme activation. We aimed to evaluate how S-benzyl-L-cysteine (SBC), an inhibitor of the sulfur assimilation pathway, affects maize plants' growth, photosynthesis, and leaf proteomic profile. Thus, maize plants were grown for 14 days in vermiculite supplemented with SBC. Photosynthesis was assessed using light and CO 2 response curves and chlorophyll a fluorescence. Leaf proteome analysis was conducted to evaluate photosynthetic protein biosynthesis, and ROS content was quantified to assess oxidative stress. Applying SBC resulted in a significant decrease in the growth of maize plants. The gas exchange analysis revealed that maize plants exhibited a diminished rate of CO 2 assimilation attributable to both stomatal and non-stomatal limitations. Furthermore, SBC suppressed the activity of important elements involved in the photosynthetic electron transport chain (including photosystems I and II, cytochrome b 6 f, and ATP synthase) and enzymes responsible for the Calvin cycle, some of which have sulfur-containing prosthetic groups. Consequently, the diminished electron flow rate resulted in a substantial increase in the levels of ROS within the leaves. Our research highlights the crucial role of SBC in disrupting maize photosynthesis by limiting L-cysteine and assimilated sulfur availability, which are essential for the synthesis of protein and prosthetic groups and photosynthetic processes, emphasizing the potential of OAS-TL as a new herbicide site of action., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

TCP (TEOSINTE-LIKE1, CYCLOIDEA, and PROLIFERATING CELL FACTOR1) is a plant-specific transcription factor that has garnered significant attention due to its wide-ranging involvement in the regulation of plant growth or developmental processes. However, the molecular mechanisms through which TCP genes orchestrate leaf senescence have not been extensively elucidated. BpTCP19, a member of the PCF subfamily in Betula platyphylla, and has high homology to AtTCP19. BpTCP19 displayed pronounced downregulation in response to methyl jasmonate (MeJA) and dark treatment. Overexpressing BpTCP19 in Betula platyphylla led to a delay in leaf senescence, resulting in prolonged leaf greenness under both MeJA and dark conditions. Transcriptome analysis revealed that overexpression of BpTCP19 induced alterations in the expression levels of genes linked to cell proliferation, hormone signaling transduction, and leaf senescence, including the early responsive factor BpWRKY53. Furthermore, through Yeast one-hybrid assays and GUS analysis, BpTCP19 was shown to bind to the promoter region of BpWRKY53, suppressing its expression and thereby retarding leaf senescence. This study elucidates the physiological and molecular functions of BpTCP19 as a central transcriptional regulatory module in leaf senescence and provides a potential target gene for delaying leaf senescence by mitigating sensitivity to external aging signals such as Jasmonic acid (JA) and darkness., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Silica nanoparticles (SiNPs) and brassinolide (BR) have been used as nano-fertilizer and growth regulator, respectively to enhance crop tolerance to abiotic stress. However, it is unclear whether a combination of the two (BR + SiNPs) is more beneficial than single application of BR or SiNPs to improve the growth of deficit-irrigated sugar beets. In this study, a two-year (2022-2023) field experiment was conducted to investigate the effects of foliar spraying of water (CK), SiNPs, BR, and BR + SiNPs on the antioxidant defense, photosynthetic capacity, dry matter accumulation, nutrient uptake, and yield of sugar beets under full irrigation (100% of crop evapotranspiration (ETc), W1) and deficit irrigation (60% ETc, W2). The results showed that compared with the application of BR or SiNPs, the application of BR + SiNPs could enhance the antioxidant defense, osmoregulation, and photosynthesis of the full-irrigated and deficit-irrigated sugar beet leaves, and ultimately improved the water status, growth, and yield of sugar beet plants. There was no significant difference in the net revenue (NR) between BR + SiNPs treatment and CK under W1 conditions. However, the NR of the BR + SiNPs treatment increased by 27.0% (p < 0.05) compared with that of CK under W2 conditions, and there was no significant difference in NR between BR + SiNPs and SiNPs treatments. A comprehensive evaluation using entropy weight combined with technique for order preference by similarity to ideal solution method found that under deficit irrigation condition, spraying SiNPs could improve the growth of sugar beet, increase the TY, NR, and water use efficiency, and reduce costs compared with spraying BR + SiNPs. Therefore, foliar spraying of SiNP on deficit-irrigated sugar beets can be used to improve sugar beet growth and reduce the potential economic losses caused by deficit irrigation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Soil salinization is a widespread environmental problem that impacts agriculture. Potassium fertilization is often associated with stress mitigation. Aiming to identify the ability of Rhodes grass (Chloris gayana Kunth) to cope with high salt as well as to investigate the potential of K + fertilization to alleviate stress symptoms, we investigated the combined effects of NaCl and KCl on photosynthesis, ion distribution, and growth of two Rhodes grass cultivars, Callide and Reclaimer. Plants were grown under different regimes (0, 200, 400, and 600 mM NaCl + 1 or 10 mM KCl). For Reclaimer, 10 mM KCl induced positive effects in photochemistry under 0 and 200 mM NaCl, as illustrated by fluorescence transients OJIP-bands and JIP-test parameters. However, such improvements did not lead to superior biomass accumulation nor net photosynthesis compared to the corresponding treatments under 1 mM KCl, which may not justify KCl application. In Callide 10 mM KCl induced deleterious effects on photochemistry of plants under low NaCl levels. High salinity (600 mM) induced stress-triggered biomass reduction of up to 70% in both cultivars, but all plants remained photosynthetically active. Exposure of both cultivars to NaCl concentrations equal to or higher than 200 mM triggered response mechanisms such as the ability to accumulate inorganic solutes accounting to osmotic potential, stomata closure, and excretion (up to 70%) of the retained Na + onto the leaf surface irrespective of KCl. Our data reinforce that Rhodes grass is an auspicious forage crop for saline environments and, therefore, in revegetation programs for saline soils pasture in subtropical regions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

With global climate change, the frequent occurrence of intense rainfall and aggravation of waterlogging disasters have severely threatened the plant growth and fruit quality of grapevines, which are commercially important fruit crops worldwide. There is accordingly an imperative to clarify the responses of grapevine to waterlogging and to propose appropriate remedial measures. Strigolactone (SL) is a phytohormone associated with plant abiotic stress tolerance, while, its function in plant responses to waterlogging stress remain undetermined. In this study, systematic analyses of the morphology, physiology, and transcriptome changes in grapevine leaves and roots under post-waterlogging and GR24 (a synthetic analog of SL) treatments were performed. Morphological and physiological changes in grapevines in response to post-waterlogging stress, including leaf wilting and yellowing, leaf senescence, photosynthesis inhibition, and increased anti-oxidative systems, could be alleviated by the application of GR24. Moreover, transcriptome analysis revealed that the primary gene functions induced by post-waterlogging stress changed over time; however, they were consistently associated with carbohydrate metabolism. The GR24-induced leaf genes were closely associated with carbohydrate metabolism, photosynthesis, antioxidant systems, and hormone signal transduction, which were considered vital aspects that were influenced by GR24 in grapevine to induce post-waterlogging tolerance. Concerning the roots, an enhancement of microtubules and cytoskeleton for cell construction in GR24 application was proposed to facilitate root system recovery after waterlogging. With this study, we comprehend the knowledge regarding the responses of grapevines to post-waterlogging and the ameliorative effect of GR24 with the insight to the transcriptome changes during these processes., Competing Interests: Declaration of competing interest The authors affirm no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Nanomaterials as an emerging tool are being used to improve plant's net photosynthetic rate (A N ) when suffering salt stress, but the underlying mechanisms remain unclear. To clarify this, a hydroponic experiment was conducted to study the effects of polyacrylic acid coated nanoceria (PNC) on the A N of salt-stressed cotton and related intrinsic mechanisms. Results showed that the PNC-induced A N enhancement of salt-stressed leaves was strongly facilitated by the mesophyll conductance to CO 2 (g m ). Further analysis showed that the PNC-induced improvement of g m was related to the increased chloroplast surface area exposed to intercellular airspaces, which was attribute to the increased mesophyll surface area exposed to intercellular airspaces and chloroplast number due to the increased K + content and decreased reactive oxygen species level in salt-stressed leaves. Interestingly, our results also showed that PNC-induced variations in cell wall composition of salt-stressed cotton leaves strongly influenced g m , especially, hemicellulose and pectin. Moreover, the proportion of pectin in cell wall composition played a more important role in determining g m . Our study demonstrated for the first time that nanoceria, through alterations to anatomical traits and cell wall composition, drove g m enhancement, which ultimately increased A N of salt-stressed leaves., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

This study elucidates the impact of element dose during nanoparticle (NPs) synthesis on plant growth indices. Novel NPs containing two essential micro-nutrients, zinc (Zn) and manganese (Mn), were co-doped on cerium oxide (CeO 2 ) (ZnMnCe) with different ratios (1, 2, and 3%). The synthesized NPs were characterized by advanced analytical techniques (EDX, TEM, SEM, XPS, and XRD) and hydroponically applied to barley (Hordeum vulgare L.). The impact of ZnMnCe NPs on growth indices and plant nutrients was examined. SEM, HRTEM, and confocal microscopy were used to show the morphological and structural influences of ZnMnCe NPs. Results showed that the plant growth indices (root/leaf length, chlorophyll fluorescence, pigmentation, and biomass) were remarkably improved with a 1% Mn/Zn addition. Conversely, growth retardation, cell membrane damage, root morphology deformation, and genotoxicity were apparent by 3% of Mn/Zn addition. Overall, a significant improvement in growth was revealed when Mn and Zn were included at 1%. However, increasing concentrations (2% and 3%) impaired the growth. These results show that the element ratio used in NPs synthesis is essential in the plant's physiological response. Precise adjustment of element dosage during NPs synthesis determines whether the NPs are beneficial or harmful. This must be well-balanced for nanofertilizer production and plant applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Nickel phytotoxicity has been attributed, among others, to oxidative stress. However, little is known about Ni-induced phospholipid modifications, including the oxidative ones. Accumulation of reactive oxygen species (ROS), antioxidative enzyme activities, malondialdehyde and the early lipid oxidation products contents, membrane permeability, phospholipid profile as well as phospholipid unsaturation degree were studied in the 1st and the 2nd leaves of hydroponically grown cucumber seedlings subjected to Ni stress. Compared to the 2nd leaf the 1st one showed stronger visual Ni toxicity symptoms, higher Ni, O 2 .- and H 2 O 2 accumulation as well as greater enhancement in membrane permeability. Enzyme activities were differently influenced by Ni stress, however most pronounced changes were generally found in the 1st leaf. Ni treatment resulted in oxidation of leaf lipids, which was evidenced by appearance of increased contents of MDA and the early produced oxylipins. Among the latter 9-hydroxyoctadecatrienoic acid (9-HOTrE) and 13-hydroxyoctadecatrienoic acid (13-HOTrE) contents showed the most pronounced increase in response to Ni treatment. Exposure to the metal led to the changes in the leaf phospholipid profile and increased degree of phospholipid unsaturation. The obtained results have been discussed in relation to the difference in Ni stress severity between the 1st and the 2nd leaves., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Nanotechnology has been widely applied in agricultural science. During the process of reducing metal toxicity and accumulation in rice, nanomaterials exhibit size effects. However, there is limited knowledge regarding these size effects. We aim to explore the impact of fertilizer with various sizes of ZnO nanoparticles (ZnO-NPs) on rice growth and cadmium (Cd) accumulation and to elucidate the potential mechanism of Cd reduction in rice. Foliar applications of different concentrations (0.5 and 2 mmol L -1 ) and different sizes (30 and 300 nm ZnO-NPs) of zinc (Zn) fertilizer (Zn(NO 3 ) 2 ) were performed to investigate the effects on rice growth, Cd accumulation and subcellular distribution, and the expression of Zn-Cd transport genes., Results: The results suggested that all the foliar sprayings can significantly reduce the Cd concentrations in rice grains by 41-61% with the highest reduction in the application of ZnO-NPs with large size and low concentration. This is related to the enhancement of Cd fixation in leaf cell walls and downregulation of Cd transport genes (OsZIP7, OsHMA2, OsHMA3) in stem nodes. Foliar ZnO-NPs applications can increase the Zn concentration in grains by 9-21%. Foliar applications of Zn(NO 3 ) 2 and small-sized ZnO-NPs promoted plant growth and rice yield, while the application of large-sized ZnO-NPs significantly reduced rice growth and yield., Conclusion: The study suggests that the rice yield and Cd reduction are dependent on the size and concentration of foliar spraying and the use of large-sized ZnO-NPs is the most effective strategy when considering both yield and Cd reduction comprehensively. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Salt stress is becoming a major issue for the world's environment and agriculture economy. Different iron [Fe] sources can give an environmentally friendly alternative for salt-affected soil remediation. In this study the effects of Iron sulfate on Luffa cylindrica (Sponge gourd) cultivated in normal and saline water irrigated soil were examined. When FeSO 4 (0.01, 0.025, 0.05, 0.1 ppm) were applied to salt affected soil, the length, fresh and dry biomass of sponge gourd plant roots and shoots inclined by an average of 33, 28, 11, 21, 18 and 22%, respectively. In plants irrigated with saline water, leaf count was raised successively (23-115%) with increasing concentration of FeSO 4 (0.025-0.1 ppm) compared to stress only plants. The use of FeSO 4 boosted sponge gourd growth characteristics in both normal and salt-affected soils compared to respective controls. The application of Iron sulfate under salt stress boosted photosynthetic indices such as chlorophyll a (22%), chlorophyll b (34%), carotenoids (16%), and total chlorophyll levels (22%). Iron sulfate application also exhibited incline in primary (total free amino acids, 50%; total soluble proteins, 46%) and secondary (total phenolics, 9%; flavonoid content, 51%) metabolites in salt-affected soils. Oxidative enzymatic activities such as catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) and DPPH scavenging activity (36%) were also increased by foliar spray of FeSO 4 in control and salt stressed L. cylindrica plants. FeSO 4 had a considerable impact on the growth and development of Luffa cylindrica in normal and salt-affected soils. It is concluded that FeSO 4 application can effectively remediate salt affected soil and improve the production of crop plants., (© 2024. The Author(s).)

Background: Exploring the adaptive responses of onions (Allium cepa L.) to salinity reveals a critical challenge for this salt-sensitive crop. While previous studies have concentrated on the effects of sodium (Na + ), this research highlights the substantial yet less-explored impact of chloride (Cl - ) accumulation. Two onion varieties were subjected to treatments with different sodium and chloride containing salts to observe early metabolic responses without causing toxicity., Results: The initial effects of salinity on onions showed increased concentrations of both ions, with Cl - having a more pronounced impact on metabolic profiles than Na + . Onions initially adapt to salinity by first altering their organic acid concentrations, which are critical for essential functions such as energy production and stress response. The landrace Birnförmige exhibited more effective regulation of its Na + /K + balance and a milder response to Cl - compared to the hybrid Hytech. Metabolic alterations were analyzed using advanced techniques, revealing specific responses in leaves and bulbs to Cl - accumulation, with significant changes observed in organic acids involved in the TCA cycle, such as fumaric acid, and succinic acid, in both varieties. Additionally, there was a variety-specific increase in ethanolamine in Birnförmige and lysine in Hytech in response to Cl - accumulation., Conclusion: This comprehensive study offers new insights into onion ion regulation and stress adaptation during the initial stages of salinity exposure, emphasizing the importance of considering both Na + and Cl - when assessing plant responses to salinity., (© 2024. The Author(s).)

Drought stress is an abiotic stressor that impacts photosynthesis, plant growth, and development, leading to decreased crop yields. Sodium hydrosulfide (NaHS), an exogenous additive, has demonstrated potential regulatory effects on plant responses to polyethylene glycol-induced drought stress in tobacco seedlings. Compared to the control, drought stress induced by 15 g/L PEG-6000 significantly reduced several parameters in tobacco seedlings: shoot dry weight (22.83%), net photosynthesis (37.55%), stomatal conductance (33.56%), maximum quantum yield of PSII (Fv/Fm) (11.31%), photochemical quantum yield of PSII (ΦPSII) (25.51%), and photochemical quenching (qP) (18.17%). However, applying NaHS, an H 2 S donor, mitigated these effects, ultimately enhancing photosynthetic performance in tobacco seedlings. Furthermore, optimal NaHS concentration (0.4 mM) effectively increased leaf stomatal aperture, relative water content (RWC) and root activity, as well as facilitated the absorption of N, K, Mg and S. It also enhanced the accumulation of soluble sugar and proline content to maintain osmotic pressure balance under drought stress. Compared to drought alone, pretreatment with NaHS also bolstered the antioxidant defense system in leaves, leading to 22.93% decrease in hydrogen peroxide (H 2 O 2 ) content, a 22.19% decrease in malondialdehyde (MDA) content and increased activities of ascorbate peroxidase (APX) by 28.13%, superoxide dismutase (SOD) by 17.07%, peroxidase (POD) by 46.99%, and catalase (CAT) by 65.27%. Consequently, NaHS protected chloroplast structure and attenuated chlorophyll degradation, thus mitigating severe oxidative damage. Moreover, NaHS elevated endogenous H 2 S levels, influencing abscisic acid (ABA) synthesis and the expression of receptor-related genes, collaboratively participating in the response to drought stress. Overall, our findings provide valuable insights into exogenous NaHS's role in enhancing tobacco drought tolerance. These results lay the foundation for further research utilizing H 2 S-based treatments to improve crop resilience to water deficit conditions., (© 2024. The Author(s).)

Nanomaterials offer considerable benefits in improving plant growth and nutritional status owing to their inherent stability, and efficiency in essential nutrient absorption and delivery. Cerium oxide nanoparticles (CeO 2 NPs) at optimum concentration could significantly influence plant morpho-physiology and nutritional status. However, it remains unclear how elevated CO 2 and CeO 2 NPs interactively affect plant growth and quality. Accordingly, the ultimate goal was to reveal whether CeO 2 NPs could alter the impact of elevated CO 2 on the nutrient composition of spinach. For this purpose, spinach plant morpho-physiological, biochemical traits, and nutritional contents were evaluated. Spinach was exposed to different foliar concentrations of CeO 2 NPs (0, 25, 50, 100 mg/L) in open-top chambers (400 and 600 CO 2  μmol/mol). Results showed that elevated CO 2 enhanced spinach growth by increasing photosynthetic pigments, as evidenced by a higher photosynthetic rate (Pn). However, the maximum growth and photosynthetic pigments were observed at the highest concentration of CeO 2 NPs (100 mg/L) under elevated CO 2 . Elevated CO 2 resulted in a decreased stomatal conductance (gs) and transpiration rate (Tr), whereas CeO 2 NPs enhanced these parameters. No significant changes were observed in any of the measured biochemical parameters due to increased levels of CO 2 . However, an increase in antioxidant enzymes, particularly in catalase (CAT; 14.37%) and ascorbate peroxidase (APX; 10.66%) activities, was observed in high CeO 2 NPs (100 mg/L) treatment under elevated CO 2 levels. Regarding plant nutrient content, elevated CO 2 significantly decreases spinach roots and leaves macro and micronutrients as compared to ambient CO 2 levels. CeO 2 NPs, in a dose-dependent manner, with the highest increase observed in 100 mg/L CeO 2 NPs treatment and increased roots and shoots magnesium (211.62-215.49%), iron (256.68-322.77%), zinc (225.89-181.49%), copper (21.99-138.09%), potassium (121.46-138.89%), calcium (118.22-91.32%), manganese (133.15-195.02%) under elevated CO 2 . Overall, CeO 2 NPs improved spinach growth and biomass and reverted the adverse effects of elevated CO 2 on its nutritional quality. These findings indicated that CeO 2 NPs could be used as an effective approach to increase vegetable growth and nutritional values to ensure food security under future climatic conditions., (© 2024. The Author(s).)

Melatonin is a bioactive molecule with an important role in plants responding to various abiotic and biotic stresses. This study aims to determine the role of melatonin in rice under salt stress. This study used a factorial completely randomized design. The first factor was local rice varieties (IR64 and Silaun), and the second factor was plant treatments (control, 1 µM melatonin, 150 mM NaCl, 150 mM NaCl + 1µM melatonin). This study shows that exogenous melatonin can increase plant growth, such as plant height, root length, stem length, leaf length, leaf area, and plant biomass under salt stress compared to treatment without melatonin. Exogenous melatonin can increase the total chlorophyll content, relative water content, and proline content, reduce the total sodium content, and increase potassium absorption under conditions of salinity stress. Melatonin is also able to scavenge ROS in plants, resulted the decrease in ROS and MDA content. In terms of gene expression, OsAPX1 and cytosolic APX exhibited the highest expression in IR64 under combined salt and melatonin treatment, while GPOD, Mn-SOD, and Cu/Zn-SOD were upregulated under various conditions in both varieties. Additionally, OsLEA showed high expression in both varieties under control conditions, and CAT was significantly upregulated under salt stress. Our findings indicate that exogenous melatonin has the potential to enhance various factors under salt stress and helping in the recovery of rice plants from sodium (Na+) damage., (© 2024. The Author(s).)

Background: Balancing nutrient application is crucial for plant growth. However, excessive fertilizer use, especially imbalanced applications of macronutrients such as phosphate (P), can hinder plant uptake of micronutrients. Balanced P and zinc (Zn) are vital for apple yield and quality, and apple trees are highly sensitive to deficiencies in these nutrients. Therefore, this study was conducted in May 2022, employed a sand culture experiment to investigate the effects of varying P and Zn levels on the growth phenotype, photosynthetic capacity, antioxidant enzyme activity, sugar composition, endogenous hormone levels, and nutrient absorption and utilization of M9-T337 seedlings. Three levels of P (low, medium, high) and three levels of Zn (low, medium, high) were combined to create a total of nine distinct treatment., Results: The results indicate that combined P and Zn fertilization at various levels exerts either synergistic or antagonistic effects on the growth, nutrient absorption, and utilization of M9-T337 seedlings. Compared to low and medium levels of P, a combination of high P (4 mmol·L -1 ) and an adequate amount of Zn significantly enhanced plant growth, root system development, and the microstructure of leaves. Notably, seedlings treated with high P and low Zn (HPLZn) reached a height 1.54 times that of the medium P and medium Zn (MPMZn, control). Physiological indicators under HP conditions revealed significant increases in antioxidant enzyme activity, leaf water retention, photosynthetic pigment concentration, osmotic adjustment substances, and the contents of glucose, sucrose, fructose, endogenous hormones, as well as P and Zn accumulation in the leaves, compared to the control. However, an increase in Zn application led to a declining trend in these parameters. Specifically, the HPLZn treatment exhibited substantial increases in Net photosynthetic rate (Pn), Total chlorophyll (Chl a + b), glucose, fructose, sucrose, and Auxin(IAA), with increments of 7.12%, 27.32%, 11.40%, 23.20%, 16.67%, and 55.11%, respectively, compared to the control., Conclusion: Based on the comprehensive ranking from principal component analysis, the combination of HP ( 4 mmol·L -1 ) and LZn (0.5 µmol·L -1 ) was found to be the most effective in enhancing the antioxidant capacity, sugar accumulation, osmotic regulation ability, photosynthetic capacity, endogenous hormone levels, as well as P and Zn nutrient absorption and utilization in M9-T337 seedlings., (© 2024. The Author(s).)

Spirotetramat is a frequently used insecticide in integrated pest management (IPM) strategies against rosy apple aphid (Dysaphis plantaginea) and woolly apple aphid (Eriosoma lanigerum) in apple cultivation. It is known that paraffin oil adjuvants increase the effect of spirotetramat against aphids. In contrast, there is a knowledge gap regarding the effects of co-applied paraffin (mineral or petroleum) oil on the degradation of spirotetramat and its metabolites (B-enol, B-keto, B-mono, and B-glu), which has not been previously investigated. Spirotetramat combined with formulated paraffin oil was tested against two aphid species and the residues of spirotetramat and its metabolites on leaves and apples were quantified using Liquid Chromatography coupled with tandem Mass Spectrometry (LC-MS/MS). The results showed that spirotetramat is highly effective against D. plantaginea, decreasing infestation by almost 100%. Furthermore, spirotetramat was shown to be effective against E. lanigerum, the reduction in infestation ranged between 67.9 and 97.7% during the last validation date. The addition of paraffin oil increased the effect of spirotetramat and affected its degradation, indicating that its efficacy could be connected to its metabolites. B-mono and B-glu were the most persistent metabolites in apple fruit overall when paraffin oil was applied., (© 2024. The Author(s).)

Background: Drought stress is a significant abiotic stressor that hinders growth, development, and crop yield in soybeans. Strigolactones (SLs) positively regulate plant resistance to drought stress. However, the impact of foliar application of SLs having different concentrations on soybean growth and metabolic pathways related to osmoregulation remains unknown. Therefore, to clarify the impact of SLs on soybean root growth and cellular osmoregulation under drought stress, we initially identified optimal concentrations and assessed key leaf and root indices. Furthermore, we conducted transcriptomic and metabolic analyses to identify differential metabolites and up-regulated genes., Results: The results demonstrated that drought stress had a significant impact on soybean biomass, root length, root surface area, water content and photosynthetic parameters. However, when SLs were applied through foliar application at appropriate concentrations, the accumulation of ABA and soluble protein increased, which enhanced drought tolerance of soybean seedlings by regulating osmotic balance, protecting membrane integrity, photosynthesis and activating ROS scavenging system. This also led to an increase in soybean root length, lateral root number and root surface area. Furthermore, the effects of different concentrations of SLs on soybean leaves and roots were found to be time-sensitive. However, the application of 0.5 µM SLs had the greatest beneficial impact on soybean growth and root morphogenesis under drought stress. A total of 368 differential metabolites were screened in drought and drought plus SLs treatments. The up-regulated genes were mainly involved in nitrogen compound utilization, and the down-regulated metabolic pathways were mainly involved in maintaining cellular osmoregulation and antioxidant defenses., Conclusions: SLs enhance osmoregulation in soybean plants under drought stress by regulating key metabolic pathways including Arachidonic acid metabolism, Glycerophospholipid metabolism, Linoleic acid metabolism, and Flavone and flavonol biosynthesis. This study contributes to the theoretical understanding of improving soybean adaptability and survival in response to drought stress., (© 2024. The Author(s).)

Background: The use of lanthanum (La) as a rare element has increased in agriculture. Summer savory (Satureja hortensis L.) is an herbaceous and medicinal plant that has received attention recently. The present study aimed to investigate the effects of foliar application of zinc (Zn), copper (Cu), manganese (Mn), and La at different growth stages, including vegetative, reproductive, and vegetative to harvest on morphological and physiological traits of S. hortensis under hydroponic and soil conditions in the greenhouse. The study was arranged in a factorial experiment based on a completely randomized design (CRD) with three replications., Results: Results of hydroponic condition showed that foliar application of Cu, Zn, and Mn were the most effective treatments to improve the measured morphological and physiological traits. Moreover, La was not more appropriate in increasing the quantitative and qualitative characteristics. Also, results showed that in soil cultivation, foliar application of micronutrient elements increased the ratio of leaf-to-stems, antioxidant compounds, and the percentage of essential oils, while the application of Mn, Cu, Zn, and La did not have positive effects on the increase in vegetative characteristics in all three stages of foliar application compared with the control treatment., Conclusions: Cu, Zn, and Mn in appropriate concentrations can increase growth and physiological characteristics of summer savory in hydroponic systems., (© 2024. The Author(s).)

Sustainable plant production in soil polluted with heavy metals requires that novel strategies are developed for the benefit of humans and other living things. Cadmium (Cd) is a common heavy metal pollutant for plants, and there is limited information on the use of exogenous bio-regulators to reduce the accumulation and toxic effects of Cd pollution in plants. Choline is an endogenous quertarnary amine that is known to improve stress tolerance in plants, while its mechanism of action in certain conditions is yet to be determined. This study investigated the effects of foliar choline supplementation (10 mM) on Solanum lycopersicum seedlings exposed to Cd application (50 mg/L in soil). The seedlings were randomized to five groups: Control (E1), Cd stress (E2), Choline supplementation after Cd stress (E3), Choline (E4), and Choline supplementation before Cd stress (E5). Following the applications, the Cd content, growth and development parameters (chlorophyll content, fresh and dry weight), oxidative stress parameters (H 2 O 2 and MDA contents), as well as antioxidative defense system (SOD, GSH, AsA, and TPC contents) were analyzed. Choline supplementation after Cd stress reduced the enhanced Cd content in roots by 38% but did not alter it in leaves (p > 0.05) compared to the Cd group. Choline supplementation before Cd stress decreased Cd content both in roots by 87.5% and in leaves by 50%. Choline supplementation after and before Cd stress increased fresh and dry weights in both roots and leaves. While the Cd group (E2) increased the H 2 O 2 level and SOD activity, no remarkable change was observed in H 2 O 2 levels in all choline supplementations (E3, E4, E5). Therefore, lipid peroxidation (MDA) was not observed in choline supplementation before Cd stress (E5), however, when the choline was applied after Cd stress (E3) MDA content was reduced by 40% compared with the Cd stress group (E2). Choline supplementations after and before Cd stress (E3, E5) increased AsA content by 30%, while the Cd group (E2) decreased it by 60% compared with the control group (E1). Choline supplementations before Cd stress (E5) increased TPC by 33%, while the Cd group (E2) decreased it by 18%, moreover, when choline was applied after Cd stress (E3), no change was observed compared to the control group. These data suggest that choline prevents inhibition of plant growth due to Cd toxicity by reducing Cd uptake. The results provided in the present study are likely to enhance the quality and efficiency of crop production in heavy metal-polluted areas., (© 2024. The Author(s).)

Background: Castor is an important industrial raw material. Drought-induced oxidative stress leads to slow growth and decreased yields in castor. However, the mechanisms of drought-induced oxidative stress in castor remain unclear. Therefore, in this study, physiological, biochemical, and RNA-seq analyses were conducted on the roots of castor plants under PEG-6000 stress for 3 d and 7 d followed by 4 d of hydration., Results: The photosynthetic rate of castor leaves was inhibited under PEG-6000 stress for 3 and 7 d. Biochemical analysis of castor roots stressed for 3 d and 7 d, and rehydrated for 4 d revealed that the activities of APX and CAT were highest after only 3 d of stress, whereas the activities of POD, GR, and SOD peaked after 7 d of stress. RNA-seq analysis revealed 2926, 1507, and 111 differentially expressed genes (DEGs) in the roots of castor plants under PEG-6000 stress for 3 d and 7 d and after 4 d of rehydration, respectively. GO analysis of the DEGs indicated significant enrichment in antioxidant activity. Furthermore, KEGG enrichment analysis of the DEGs revealed significantly enriched metabolic pathways, including glutathione metabolism, fatty acid metabolism, and plant hormone signal transduction. WGCNA identified the core genes PP2C39 and GA2ox4 in the navajowhite1 module, which was upregulated under PEG-6000 stress. On the basis of these results, we propose a model for the response to drought-induced oxidative stress in castor., Conclusions: This study provides valuable antioxidant gene resources, deepening our understanding of antioxidant regulation and paving the way for further molecular breeding of castor plants., (© 2024. The Author(s).)

Melatonin has been found to be crucial in the growth and development of plants under stress conditions. In this study, the effects of melatonin and nano melatonin regarding the growth and development of tomato plants, along with their photosynthetic pigment, phenol, and antioxidant activity, were investigated under saline conditions. The study was conducted using a completely randomized design with three replications, and the applied treatments were salt stress and foliar spraying of melatonin at a concentration of 0 (control), melatonin (Mel), and nano capsule-melatonin (Nano-Mel) at 500 µM. Salinity treatments included application of sodium chloride with two concentration of 0 mM NaCl (S1) and 50 mM NaCl (S2). Under saline conditions, Mel and Nano-Mel increased both shoot and root fresh and dry weights, improved relative water content (RWC), and enhanced antioxidant activity and phenolic content. Salinity elevated leaf ABA content, unaffected by Mel or Nano-Mel. Chlorophyll fluorescence and SPAD values demonstrated resilience to salinity with Mel and Nano-Mel applications. Nano-Mel notably mitigated Na + accumulation in leaves under salinity, helping maintain K + homeostasis. Proline levels rise due to salinity but decreased with Mel and Nano-Mel treatments. Electrolyte leakage (EL) increased under salinity but is significantly reduced by Mel, indicating enhanced membrane stability. The findings reveal that salinity stress significantly reduced plasma membrane intrinsic protein (PIP) expression in roots and leaves, whereas Mel and Nano-Mel treatments enhance PIP expression, particularly in roots. The study concludes that Mel and Nano-Mel effectively alleviate salinity-induced stress, promoting growth and maintaining physiological homeostasis in tomato plants., (© 2024. The Author(s).)

Background: Secondary metabolites of several plants, including esculin and digitoxin, which are cardiac glycosides, were previously employed for their therapeutic effects. The current study aims to investigate the functions of the main Na + /K + transport inhibitor digitoxin and the antioxidant esculin for enhancing flax plant growth and production under salinity., Methodology: Flax plants were irrigated with distilled water supplemented with 0.0 and 5000 mg/L salt solution starting from 15 DAS from sowing. Then exogenous treatment with digitoxin and esculin with 50 mg L - 1 and 100 mg L - 1 were used for this work., Results: According to the results of this work, foliar spraying of esculin or digitoxin increased the salinity tolerance of flax plants.The foliar application of either esculin or digitoxin induced an elevation in the contents of photosynthetic pigments, osmolytes including soluble sugar and proline as well as the total phenols in salt-stressed flax plants. Moreover, esculin and digitoxin in particular counteract oxidative stress by increasing the activity of antioxidant enzymes including superoxide dismutase, catalase, peroxidase, phenylalanine ammonia-lyase, and tyrosine ammonia lyase, leading to a decrease in reactive oxygen species and lipid peroxidation levels and electrolyte leakage. The efficiency of esculin and digitoxin to sustain ion homeostasis by inhibiting Na + absorption and increasing potassium, calcium, and phosphorus in flax plants may be the reason for their protective actions towards salinity.As a consequence, esculin and digitoxin increased yield quantity and quality as shown by increases in all investigated yield criteriaas shoot height, root length, their fresh and dry weights as well asseed yield/plant (g), and 1000 seeds weight, especially those that improved the desired oil properties., Conclusion: In conclusion, this study concluded that digitoxin was more effective in inhibiting Na + build-up and increasing flax salinity tolerance, particularly at the high investigated dose as compared to esculin. In this study, we reported the recent findings of exogenousapplication of either digitoxin or esculin glycosides which are new investigated salt alleviators never used before for improving the salt tolerance in flax plants., (© 2024. The Author(s).)

Due to the continuous production of industrial wastes and the excessive use of chemical fertilizers and pesticides, severe cadmium (Cd) pollution in soil has occurred globally. This study investigated the impacts of incorporating zinc oxide nanoparticles (ZnONPs) into hydroponically grown lettuce (Lactuca sativa) under cadmium stress conditions, to seek effective methods to minimize Cd buildup in green leafy vegetables. The results showed that 1 mg/L of Cd significantly inhibited lettuce growth, decreasing in leaves (29 %) and roots (33 %) biomass. However, when lettuce was exposed to 2.5 mg/L ZnONPs under cadmium stress, the growth, chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), actual photochemical efficiency of PSII (φPSII), and activity of key enzymes in photosynthesis were all significantly enhanced. Furthermore, ZnONPs significantly decreased the accumulation of Cd in lettuce leaves (36 %) and roots (13 %). They altered the subcellular distribution and chemical morphology of Cd in lettuce by modifying the composition of cell walls (such as pectin content) and the levels of phenolic compounds, resulting in a reduction of 27 % in Cd translocation from roots to leaves. RNA sequencing yielded 45.9 × 10 7 and 53.4 × 10 7 clean reads from plant leaves and roots in control (T0), Cd (T1), Cd+ZnONPs (T2), and ZnONPs (T3) treatment groups respectively, and 3614 and 1873 differentially expressed genes (DEGs) were identified. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified photosynthesis, carbon fixation, and phenylpropanoid metabolism as the main causes of ZnONPs-mediated alleviation of Cd stress in lettuce. Specifically, the DEGs identified included 12 associated with photosystem I, 13 with photosystem II and 23 DEGs with the carbon fixation pathway of photosynthesis. Additionally, DEGs related to phenylalanine ammonia-lyase, caffeoyl CoA 3-O-methyltransferase, peroxidase, 4-coumarate-CoA ligase, hydroxycinnamoyl transferase, and cytochrome P450 proteins were also identified. Therefore, further research is recommended to elucidate the molecular mechanisms by which ZnONPs reduce Cd absorption in lettuce through phenolic acid components in the phenylpropanoid metabolism pathway. Overall, treatments with ZnONPs are recommended to effectively reduce Cd accumulation in the edible portion of lettuce., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The advancement and intensification of industrial and mining activities has generated a series of impacts on natural ecosystems, combined with the inappropriate use of agrochemicals and the erroneous disposal of electronic products, contributing to soil contamination with a diversity of chemical elements, including heavy metals. Due to this, this work aimed to evaluate the effect of increasing dosages of nickel on the anatomy, biochemistry and oxidative system of Brazilian mahogany (Swietenia macrophylla), a forest species from the Amazon, seeking to indicate the potential use of this species in phytoremediation programs. of soils contaminated with heavy metals. The seeds were grown under a constant temperature of 28°C, relative humidity (RH) of 90% with a 12-hour photoperiod for 43 days. The experimental design used was randomized blocks (DBC), with five treatments (0, 2, 4, 6 and 8 mg.L-1 of Nickel), with six replications. Data were subjected to analysis of variance (ANOVA) and means were tested for significant differences using the Tukey test at 5% significance. Changes in the anatomy of the different organs were observed, with differences in the cells in the central region of the leaf, the stem and the root. The concentration of total carbohydrates had no statistical differences with the application of nickel, however changes were observed in photosynthetic pigments, reducing sugars and sucrose as an adaptive form to nickel. The increase in nickel dosages was accompanied by the synthesis of ammonium, amino acids and proline in the root, while the synthesis of glycine was reduced. In the leaf, there was an increase in amino acids with an increase in metal, accompanied by a decrease in glycine. The plant antioxidant defense system was efficient in attenuating the toxic effects of ROS, with significant actions of CAT and SOD enzymes in the root, while the leaf had the main action of APX and CAT. The cultivation of mahogany plants can be advocated to mitigate Ni pollution in these areas, as this forest species has a particular characteristic of resistance to stressful conditions in contact with the heavy metal.

Soil autotoxic chemosensory substances have emerged as the predominant environmental factors constraining the growth, quality, and yield of Codonopsis pilosula in recent years. Among a vast array of chemosensory substances, benzoic acid constitutes the principal chemosensory substance in the successive cultivation of C. pilosula . However, the exploration regarding the stress exerted by benzoic acid on the growth and development of C. pilosula remains indistinct, and there is a scarcity of research on the mechanism of lobetyolin synthesis in C. pilosula . In the current research, it was discovered that exposure to benzoic acid at a concentration of 200 mmol/L conspicuously attenuated the plant height, root length, total length, fresh weight, root weight, root thickness, chlorophyll content, electrolyte osmolality, leaf intercellular CO 2 concentration (C i ), net photosynthesis rate (P n ), transpiration rate (T r ), and leaf stomatal conductance (G s ) of C. pilosula . Benzoic acid (200 mmol/L) significantly enhanced the activity of root enzymes, including superoxide dismutase (SOD), malondialdehyde (MDA), and peroxidase (POD), as well as the accumulation of polysaccharides and lobetyolins (polyacetylene glycosides) in the roots of C. pilosula . In this study, 58,563 genes were assembled, and 7946 differentially expressed genes were discovered, including 4068 upregulated genes and 3878 downregulated genes. The outcomes of the histological examination demonstrated that benzoic acid stress augmented the upregulation of genes encoding key enzymes implicated in the citric acid cycle, fatty acid metabolism, as well as starch and sucrose metabolic pathways. The results of this investigation indicated that a moderate amount of benzoic acid could enhance the content of lobetyolin in C. pilosula and upregulate the expression of key coding genes within the signaling cascade to improve the resilience of C. pilosula lobetyolin against benzoic acid stress; this furnished a novel perspective for the study of C. pilosula lobetyolin as a potential substance for alleviating benzoic acid-induced stress.

Background: Soil salinization is a serious environmental hazard, limiting plant growth and production in different agro-ecological zones worldwide. Diethyl aminoethyl hexanoate (DA-6) as an essential plant growth regulator (PGR) exhibits a beneficial role in improving crop growth and stress tolerance. However, the DA-6-regulated effect and mechanism of salt tolerance in plants are still not fully understood. The objective of current study was to disclose salt tolerance induced by DA-6 in relation to changes in water and redox balance, photosynthetic function, ionic homeostasis, and organic metabolites reprogramming in white clover (Trifolium repens)., Results: A prolonged duration of salt stress caused water loss, impaired photosynthetic function, and oxidative injury to plants. However, foliar application of DA-6 significantly improved osmotic adjustment (OA), photochemical efficiency, and cell membrane stability under salt stress. In addition, high salinity induced massive accumulation of sodium (Na), but decreased accumulation of potassium (K) in leaves and roots of all plants. DA-6-treated plants demonstrated significantly higher transcript levels of genes involved in uptake and transport of Na and K such as VP1, HKT8, SOS1, NHX2, NHX6, and SKOR in leaves as well as VP1, HKT1, HKT8, H + -ATPase, TPK5, SOS1, NHX2, and SKOR in roots. Metabolomics analysis further illustrated that DA-6 primarily induced the accumulation of glucuronic acid, hexanoic acid, linolenic acid, arachidonic acid, inosose, erythrulose, galactopyranose, talopyranose, urea, 1-monopalmitin, glycerol monostearate, campesterol, stigmasterol, and alanine., Conclusions: The DA-6 significantly up-regulated transcript levels of multiple genes associated with increased Na + compartmentalization in vacuoles and Na + sequestration in roots to reduce Na + transport to photosynthetic organs, thereby maintaining Na + homeostasis under salt stress. The accumulation of many organic metabolites induced by the DA-6 could be attributed to enhanced cell wall and membrane structural stability and functionality, OA, antioxidant defense, and downstream signal transduction in leaves under salt stress. The present study provides a deep insight about the synergistic role of DA-6 in salt tolerance of white clover., (© 2024. The Author(s).)

Carbon Dots (CDs) were synthesized from peanut shells (PNS) through pyrolysis and characterized using FTIR, XRD, HRTEM and BET analysis revealing an average size of 2-5 nm with amorphous nature. Synthesized PNS-CDs was employed both as priming and foliar agent for enhancing seed quality and crop productivity in blackgram (Vigna mungo L. Hepper). Different concentrations ranging from 50, 100, 200, 300, 400, 500 and 1000 ppm was used for seed priming and 5, 10, 15, 20, 25, 50, 75 and 100 ppm were given as foliar spray on 30 th and 45 th days after sowing (DAS). On accounting the best seed priming and foliar spray concentrations, field trial was conducted to validate the optimistic effect of PNS-CDs on blackgram crop productivity. Results revealed that priming with 200 ppm for 3 h exhibited maximum seed imbibition (54%), germination (88%) and vigour index (3165). Whereas, foliar spray with 50 ppm expressed significant improvement in leaf area index (2.6), total chlorophyll (2.70 mg/g), total soluble protein (71 mg/g), Number of nodules/plant (138), seed yield/plant (8.7 g) and 100 seed weight (5 g). The impact of PNS-CDs treatments resulted in increased photosynthetic rate (12.45 µmol CO 2 m -2 s -1 ), transpiration rate (3.13 mmol H 2 O/m -2 s -1 ), stomatal conductance (0.55 mol H 2 O/m -2 s -1 ) and internal leaf CO 2 concentration (652 µmol CO 2 m -2 s -1 ) which ultimately enhanced the photosynthetic efficiency of plants. It has also exhibited a promising effect on the resultant seed in which the combination seed priming (200 ppm) followed by foliar spray (50 ppm) recorded maximum 100 seed weight (4.19 g), germination (97%) and vigour index (3019). Thus, this study highlights the promising role of PNS-CDs as a sustainable and effective agricultural nanomaterial, offering a novel approach to utilize the agricultural waste and also to enhance the crop productivity through advanced non-chemical approach., (© 2024. The Author(s).)

Key Message: Hydrogen peroxide promoted leaf senescence by sulfenylating the magnesium chelating protease I subunit (CHLI1) in the chlorophyll synthesis pathway, and inhibited its activity to reduce chlorophyll synthesis. Leaf senescence is the final and crucial stage of plant growth and development, during which chlorophyll experiences varying degrees of destruction. It is well-known that the higher ROS accumulation is a key factor for leaf senescence, but whether and how ROS regulates chlorophyll synthesis in the process are unknown. Here, we report that H 2 O 2 inhibits chlorophyll synthesis during leaf senescence via the I subunit of magnesium-chelatase (CHLI1). During leaf senescence, the decrease of chlorophyll content is accompanied by the increase of H 2 O 2 accumulation, as well as the inhibition of catalase (CAT) genes expression. The mutant cat2-1, with increased H 2 O 2 shows an accelerated senescence phenotype and decreased CHLI1 activity compared with the wild type. H 2 O 2 inhibits CHLI1 activity by sulfenylating CHLI1 during leaf senescence. Consistent with this, the chli1 knockout mutant displays the same premature leaf senescence symptom as cat2-1, while overexpression of CHLI1 in cat2-1 can partially restore its early senescence phenotype. Taken together, these results illustrate that CAT2-mediated H 2 O 2 accumulation during leaf senescence represses chlorophyll synthesis through sulfenylating CHLI1, and thus inhibits its activity, providing a new insight into the pivotal role of chlorophyll synthesis as a participant in orchestrating the leaf senescence., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The effect of methyl jasmonate (MeJA) foliar spray on the activity of antioxidant enzymes-Superoxide dismutase (SOD), Catalase (CAT), Ascorbate peroxidase (APX), and Guaiacol peroxidase (GPX)-along with assessments of total phenolic and flavonoid contents and antioxidant activity (IC50), was examined in Prickly lettuce (Lactuca serriola L.). The study involved treating plants with three MeJA solutions (0, 200, and 400 µM) and harvesting samples at four distinct time intervals. Varied MeJA concentrations and time intervals resulted in a substantial increase in the activity of all the antioxidant enzymes investigated in this study. Both concentration levels and time courses exhibited progressive outcomes. Moreover, MeJA treatment led to elevated levels of total phenolic and flavonoid contents, reaching peaks of 17.02 (mg GAL/g DW) and 8.3 (mg QUE/g DW), respectively, particularly in response to the 400 µM concentration. However, the total flavonoid content did not show any significant variation between the two concentrations. Based on the half-maximal inhibitory concentration (IC50) values, the antioxidant activity in MeJA-treated plants was found to be lower compared to the controls. However, our findings suggest that, under specific conditions discussed in this study, MeJA has the potential to enhance the nutritional value of L. serriola.

Heat stress, low mango yields and inconsistent fruit quality are main challenges for growers. Recently, licorice-root extract (LRE) has been utilized to enhance vegetative growth, yield, and tolerance to abiotic stresses in fruit trees. Potassium sorbate (PS) also plays a significant role in various physiological and biochemical processes that are essential for mango growth, quality and abiotic stress tolerance. This work aimed to elucidate the effects of foliar sprays containing LRE and PS on the growth, yield, fruit quality, total chlorophyll content, and antioxidant enzymes of 'Osteen' mango trees. The mango trees were sprayed with LRE at 0, 2, 4 and 6 g/L and PS 0, 1, 2, and 3 mM. In mid-May, the mango trees were sprayed with a foliar solution, followed by monthly applications until 1 month before harvest. The results showed that trees with the highest concentration (6 g/L) of LRE exhibited the maximum leaf area, followed by those treated with the highest concentration (3 mM) of PS. Application of LRE and PS to Osteen mango trees significantly enhanced fruit weight, number of fruits per tree, yield (kg/tree), yield increasing%, and reduced number of sun-burned fruits compared to the control. LRE and PS foliar sprays to Osteen mango trees significantly enhanced fruit total soluble solids ˚Brix, TSS/acid ratio, and vitamin C content compared to the control. Meanwhile, total acidity percentage in 'Osteen' mango fruits significantly decreased after both LRE and PS foliar sprays. 'Osteen' mango trees showed a significant increase in leaf area, total chlorophyll content, total pigments, and leaf carotenoids. Our results suggest that foliar sprays containing LRE and PS significantly improved growth parameters, yield, fruit quality, antioxidant content, and total pigment concentration in 'Osteen' mango trees. Moreover, the most effective treatments were 3 mM PS and 6 g/L LRE. LRE and PS foliar spray caused a significant increase in yield percentage by 305.77%, and 232.44%, in the first season, and 242.55%, 232.44% in the second season, respectively., Competing Interests: The authors declare that they have no competing interests., (© 2024 Al-Saif et al.)

Hymenaea stigonocarpa Mart. ex Hayne has leaves with adaxial and abaxial epidermis covered by a very thick cuticle, in addition to anatomical structures involved in reducing the amount of herbicide absorbed by plants. Thus, we tested the hypothesis that H. stigonocarpa is potentially resistant to the herbicide glyphosate, exposing the plants to different doses (0, 96, 240, 480, and 960 g a.e ha-1). We carried out assessments of the symptoms, anatomy, growth and physiology of the plants and found that exposure to glyphosate negatively affected the height and number of leaves of the plants. Leaf fall resulted in a reduction in the photosynthetic capacity of plants, which responded by investing in stem diameter. Despite this, no visual symptoms of glyphosate toxicity were observed at the concentrations evaluated and histochemical tests did not detect signs of oxidative stress in the leaves, nor starch accumulation, indicating that carbohydrate translocation was not impaired. These results confirm our hypothesis of tolerance of H. stigonocarpa to glyphosate. Furthermore, plants exposed to the lowest doses of glyphosate (96 and 240 g ha-1) showed good growth, photosynthesis, transpiration and photochemical potential responses, indicating a hormetic effect in this application range.

Both sulfur (S) supply and legume-rhizobium symbiosis can significantly contribute to enhancing the efficiency of phytoremediation of heavy metals (HMs). However, the regulatory mechanism determining the performance of legumes at lead (Pb) exposure have not been elucidated. Here, we cultivated black locust (Robinia pseudoacacia L.), a leguminous woody pioneer species at three S supply levels (i.e., deficient, moderate, and high S) with rhizobia inoculation and investigated the interaction of these treatments upon Pb exposure. Our results revealed that the root system of Robinia has a strong Pb accumulation and anti-oxidative capacity that protect the leaves from Pb toxicity. Compared with moderate S supply, high S supply significantly increased Pb accumulation in roots by promoting the synthesis of reduced S compounds (i.e., thiols, phytochelatin), and also strengthened the antioxidant system in leaves. Weakened defense at deficient S supply was indicated by enhanced oxidative damage. Rhizobia inoculation alleviated the oxidative damage of its Robinia host by immobilizing Pb to reduce its absorption by root cells. Together with enhanced Pb chelation in leaves, these mechanisms strengthen Pb detoxification in the Robinia-rhizobia symbiosis. Our results indicate that appropriate S supply can improve the defense of legume-rhizobia symbiosis against HM toxicity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sunflower (Helianthus annuus) can potentially be used for uranium (U) phytoremediation. However, the factors influencing the absorption of U and its subsequent distribution within plant tissues remain unclear, including the effect of silicon (Si) which is known to increase metal tolerance. Here, using hydroponics, the effect of Si on the distribution and speciation of U in sunflower was examined using synchrotron-based X-ray fluorescence and fluorescence-X-ray absorption near-edge spectroscopy. It was found that ∼88 % of U accumulates within the root regardless of treatments. Without the addition of Si, most of the U appeared to bind to epidermis within the roots, whereas in the leaves, U primarily accumulated in the veins. The addition of Si alleviated U phytotoxicity and decreased U concentration in sunflower by an average of 60 %. In the roots, Si enhanced U distribution in cell walls and impeded its entry into cells, likely due to increased callose deposition. In the leaves, Si induced the sequestration of U in trichomes. However, Si did not alter U speciation and U remained in the hexavalent form. These results provide information on U accumulation and distribution within sunflower, and suggest that Si could enhance plant growth under high U stress., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Bassinosteroids (BRs) can induce plant defence responses and promote plant growth. In this work, we evaluated the effect of a natural (EP24) and a synthetic (BB16) brassinosteroid on strawberry (Fragaria vesca ) plants exposed to saline stress. Treated plants showed higher shoot dry weight and root growth compared to untreated control plants. In BR-treated plants, crown diameters increased 66% and 40%, leaf area 148% and 112%, relative water content in leaves 84% and 61%, and SPAD values 24% and 26%, in response to BB16 and EP24, respectively. A marked stomatal closure, increased leaflet lignification, and a decrease in cortex thickness, root diameter and stele radius were also observed in treated plants. Treatments also reduces stress-induced damage, as plants showed a 34% decrease in malondialdehyde content and a lower proline content compared to control plants. A 22% and 15% increase in ascorbate peroxidase and total phenolic compound activities was observed in response to BB16, and a 24% increase in total flavonoid compound in response to both BRs, under stress conditions. These results allow us to propose the use of BRs as an environmentally safe crop management strategy to overcome salinity situations that severely affect crop yield.

Drought-induced stress represents one of the most economically detrimental natural phenomena impacting grapevine (Vitis vinifera ) development, yield, and fruit characteristics. Also, auxin is one of the most important plant growth regulators that can reduce damage caused by stress in plants. In this study, the impact of exogenously sprayed auxin (0, 50, and 200mgL-1 ) on growth, biochemical, and anatomical parameters was investigated in two grapevine varieties (cvs. 'Rashe' and 'Fakhri') under water deficit. According to our findings, water deficit led to a notable decrease in growth, protein content, and anatomical parameters; but significantly enhanced electrolyte leakage. Grapevines exposed to water deficit exhibited substantial increases in total phenolic compounds and antioxidant activity. Applying 50mgL-1 napthalene acetic acid (NAA) reduced the effects of water deficit in both grapevine cultivars by decreasing electrolyte leakage (15% in 'Rashe' and 20% in 'Fakhri'), and accumulating protein content (22% 'Rashe' and 32% 'Fakhri'), total phenolic compounds (33%'Rashe' and 40% 'Fakhri'), and antioxidant capacity (11% 'Rashe' and 39% 'Fakhri'); anantomical parameters were also improved. However, application of 200mgL-1 NAA had adverse effects on growth and biochemical traits of grapevines, with a more pronounced impact on root growth and anatomical parameters compared to other NAA concentrations. In conclusion, the application of 50mgL-1 NAA enhanced grapevine growth, enabling them to better thrive under water deficit.