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The influence of biostimulant treatments on Passiflora species was assessed by observing changes in the growth and leaf functional compounds of plants exposed to humic acids (HAs) and seaweed extracts (SEs) to determine their optimal application doses. Four different concentrations of HA irrigation (0, 144, 192, and 285 mg·L-1 per pot assigned as HI-1, 2, 3, and 4, respectively), HA spraying (0, 96, 128, and 192 mg·L-1 as HS-1, 2, 3, and 4, respectively), SE irrigation (SI-1~4 at 0, 1, 1.33, and 2 g·L21 per pot, respectively), and SE spraying (SS-1~4 at 0, 0.5, 0.67, and 1 g·L21, respectively) treatments were applied to 'Tainung No. 1' and Passiflora suberosa cultivars every week to study their responses in plant growth traits and metabolites. Results show that leaf dry weight (DW) and root DW of 'Tainung No. 1' plants under SS-3 and HI-4 treatments, respectively, were significantly increased compared with controls. Both HI-3 and HS-3 treatments remarkably increased vine length, fresh weight (FW), and DW of leaves and shoots in P. suberosa plants compared with controls. Furthermore, 'Tainung No. 1' and P. suberosa plants respectively subjected to HI-2 and SS-4 treatments contributed to developing biostimulant applications for obtaining higher total phenol and flavonoid content per plant. Both Passiflora species are recommended for treatment with SS-4 and SE to maximize orientin and isovitexin content, and for all their beneficial applications and sustainable use in agriculture. [ABSTRACT FROM AUTHOR]

Plant wearable sensors have shown exceptional promise in continuously monitoring plant health. However, the potential adverse effects of these sensors on plant growth remain unclear. This study systematically quantifies wearable sensors' interference with plant growth using two ornamental species, Peperomia tetraphylla and Epipremnum aureum. We evaluated the impacts of four common disturbances—mechanical pressure, hindrance of gas exchange, hindrance of light acquisition, and mechanical constraint—on leaf growth. Our results indicated that the combination of light hindrance and mechanical constraint demonstrated the most significant interference. When the sensor weight was no greater than 0.6 g and the coverage was no greater than 5% of the leaf area, these four disturbances resulted in slight impacts on leaf growth. Additionally, we fabricated a minimally interfering wearable sensor capable of measuring the air temperature of the microclimate of the plant while maintaining plant growth. This research provides valuable insights into optimizing plant wearable sensors, balancing functionality with minimal plant interference. [ABSTRACT FROM AUTHOR]

The polar auxin transport is required for proper plant growth and development. D6 PROTEIN KINASE (D6PK) is required for the phosphorylation of PIN‐FORMED (PIN) auxin efflux carriers to regulate auxin transport, while the regulation of D6PK stabilization is still poorly understood. Here, we found that Cytosolic ABA Receptor Kinases (CARKs) redundantly interact with D6PK, and the interactions are dependent on CARKs' kinase activities. Similarly, CARK3 also could interact with paralogs of D6PK, including D6PKL1, D6PKL2, and D6PKL3. The genetic analysis shows that D6PK acts the downstream of CARKs to regulate Arabidopsis growth, including hypocotyl, leaf area, vein formation, and the length of silique. Loss‐of‐function of CARK3 in overexpressing GFP‐D6PK plants leads to reduce the level of D6PK protein, thereby rescues plant growth. In addition, the cell‐free degradation assays indicate that D6PK is degraded through 26 S proteasome pathway, while the phosphorylation by CARK3 represses this process in cells. In summary, D6PK stabilization by the CARK family is required for auxin‐mediated plant growth and development. Summary statement: The AGC VIII kinase D6 PROTEIN KINASE (D6PK) phosphorylates PIN‐FORMED (PIN) auxin efflux carriers, which is essential for auxin transport in plant cells. This study uncovers a new mechanism for D6PK stability through Cytosolic ABA Receptor Kinases‐mediated phosphorylation to regulate auxin‐controlled Arabidopsis growth and development. [ABSTRACT FROM AUTHOR]

Phosphorus (P) deficiency is one of the main reasons limiting plant production of Brassica napus L. Exploring the dynamics of leaf intracellular substances and the correlations with photosynthesis and growth helps to understand the response mechanisms of B. napus L. to P deficiency. This study conducted experiments on B. napus L. plants by measuring the leaf electrophysiological parameters, leaf structure, elastic modulus (Em), photosynthesis, and growth indices under different P treatment conditions. The dynamics of leaf intracellular water and nutrients of B. napus L. were calculated and analyzed by using the electrophysiological parameters, and the plant tolerance threshold to low-P stress was discovered. The results indicated that the status of the leaf intracellular water and nutrients remained stable when the P concentration was not lower than 0.250 mmol·L−1, but maximized the photosynthesis and growth at a P level of 0.250 mmol·L−1. The 0.125 mmol·L−1 P concentration significantly decreased the mesophyll cell volume, and the palisade–sponge ratio and tightness degree of leaf tissue structure were remarkably increased. This led to an increase in cell elastic modulus, and significantly improved the water retention capacity of leaf cells. At the same time, the intracellular water use efficiency and total nutrient transport capacity of leaves remained stable. As a result, the photosynthesis and growth of plants were maintained at the same level as that of the control group. However, photosynthesis and growth were clearly inhibited with a further decrease in P concentration. Therefore, 0.125 mmol·L−1 was the tolerance threshold of B. napus L. to low P. With the help of electrophysiological information, the effects of the dynamics of intracellular substances on photosynthesis and growth of B. napus L. under low-P stress can be investigated, and the plant's adaptive response can be revealed. However, the findings of the current hydroponic study are not directly applicable to field conditions with naturally P-deficient soils. [ABSTRACT FROM AUTHOR]

Iron (Fe) is a crucial micronutrient needed in many metabolic processes. To balance needs and potential toxicity, plants control the amount of Fe they take up and allocate to leaves and seeds during their development. One important regulator of this process is POPEYE (PYE). PYE is a Fe deficiency-induced key bHLH transcription factor (TF) for allocation of internal Fe in plants. In the absence of PYE, there is altered Fe translocation and plants develop a leaf chlorosis. NICOTIANAMINE SYNTHASE4 (NAS4), FERRIC-REDUCTION OXIDASE3 (FRO3), and ZINC-INDUCED FACILITATOR1 (ZIF1) genes are expressed at higher level in pye-1 indicating that PYE represses these genes. PYE activity is controlled in a yet unknown manner. Here, we show that a small Fe deficiency-induced protein OLIVIA (OLV) can interact with PYE. OLV has a conserved C-terminal motif, that we named TGIYY. Through deletion mapping, we pinpointed that OLV TGIYY and several regions of PYE can be involved in the protein interaction. An OLV overexpressing (OX) mutant line exhibited an enhanced NAS4 gene expression. This was a mild Fe deficiency response phenotype that was related to PYE function. Leaf rosettes of olv mutants remained smaller than those of wild type, indicating that OLV promotes plant growth. Taken together, our study identified a small protein OLV as a candidate that may connect aspects of Fe homeostasis with regulation of leaf growth. [ABSTRACT FROM AUTHOR]

Soil moisture resources are highly spatially and temporally heterogeneous. Although temporal heterogeneous water conditions have a more common impact on plants than spatial heterogeneous conditions, very few studies have been conducted to investigate how plants respond to existing temporally heterogeneous water conditions. To address this issue, we adopted three species with different habitat ranges, including a karst-endemic species of Kmeria septentrionalis (growing in karst habitats only), a karst-suitable species of Celtis sinensis (occur in both habitats) and a non-karst species of Lithocarpus glaber (found in normal habitats only), and conducted a greenhouse experimental study at Guizhou University, Guiyang, China. This study explored the response ability and coping strategies of seedlings from various habitats by comparing the differences in growth of biomass, and physiological traits of the three species in response to temporally heterogeneous water (alternating drought and waterlogging) and temporally homogeneous water (constant moist) treatments. Compared with constant moist treatment, the first round of temporally heterogeneous water treatment reduced the growth of leaf, root, and total biomass increased the contents of osmoregulation substances, malondialdehyde, and antioxidant enzyme activities. However, the third round of temporally heterogeneous water treatment improved their late growth of biomass, and the content of physiological traits was also significantly decreased. K. septentrionalis showed a higher compensation effect in late growth by early heterogeneous experience. Typical karst species may be more able to benefit from early experience with temporally heterogeneous environments, due to long-term adaptation to karst habitats of great heterogeneity and low resource availability. The temporally heterogeneous water conditions can induce plants to produce a higher physiological response, and inhibit the current growth of plants, but can enhance the adaptability of plants to similar stress events in the later period. The ability of species to respond to temporally heterogeneous water treatment may be related to their habitat range. [ABSTRACT FROM AUTHOR]

Summary: To play essential roles of manganese (Mn) in plant growth and development, it needs to be transported to different organs and tissues after uptake. However, the molecular mechanisms underlying Mn distribution between different tissues are poorly understood.We functionally characterized a member of rice natural resistance‐associated macrophage protein (NRAMP) family, OsNramp5 in terms of its tissue specificity of gene expression, cell‐specificity of protein localization, phenotypic analysis of leaf growth and response to Mn fluctuations.OsNramp5 is highly expressed in the leaf sheath. Immunostaining revealed that OsNramp5 is polarly localized at the proximal side of xylem parenchyma cells of the leaf sheath. Both the gene expression and protein abundance of OsNramp5 are unaffected by different Mn concentrations. Knockout of OsNramp5 decreased the distribution of Mn to the leaf sheath, but increased the distribution to the leaf blade at both low and high Mn supplies, resulting in reduced growth of leaf sheath. Furthermore, expression of OsNramp5 under the control of root‐specific promoter in osnramp5 mutant complemented Mn uptake, but could not complement Mn distribution to the leaf sheath.These results indicate that OsNramp5 expressed in the leaf sheath plays an important role in unloading Mn from the xylem for the local distribution in rice. [ABSTRACT FROM AUTHOR]

Functional traits have been proposed to define key dimensions of plant ecological strategies, but we lack consensus on whether traits can accurately predict plant demography. Despite theoretical expectations, it has been challenging to find consistent relationships between functional traits and growth.In this study, we quantified inter‐ and intraspecific trait variation (ITV) and individual growth rates of woody plants across a steep moisture gradient that varies 10‐fold in annual precipitation (350–3700 mm) in southern Chile and used a hierarchical Bayesian model to predict growth as a function of trait values.We show that large‐leaved species with lower stem tissue density exhibited the fastest growth rates, and these two traits exhibited the highest proportion of interspecific variation. Predictions of growth improved considerably (R2 of the best model increased from 0.28 to 0.49) when species‐level multiple traits and their interactions were considered. The inclusion of ITV, however, did not improve models of growth rate.We found that trait–growth rate relationships were not always consistent across levels of biological organization; relationships observed at the interspecific level did not necessarily hold at the intraspecific level. We found that the relationships between wood density or leaf size and growth were consistent in direction across the precipitation gradient, and the relationships between leaf economics traits and growth were weak and site‐specific.Synthesis. Although using more than one functional trait considerably improved growth predictions, wood density and leaf size successfully predicted growth rates across (not within) species, which is consistent with a whole‐plant carbon economy. We assert that these two traits are intimately linked and ultimately describe a continuum of plant architecture and carbon economy that covers multiple trait syndromes. [ABSTRACT FROM AUTHOR]

In vitro propagation is a crucial method for the mass production of high-quality plants, but the impact of microbiological interventions during ex vitro storage remains an underexplored aspect. This study aims to assess the effects of three commercial biostimulants in the form of microbiological preparations—BactoFungiStop, AzotoPower, and Guard—applied over six months through foliar sprays on the post-storage quality of Brunnera macrophylla 'Silver Heart', Echinacea purpurea 'Secret Glow', Heuchera × hybrida 'Northern Exposure Red', Persicaria amplecicaulis 'JS Caliente', and Rudbeckia × hybrida 'Sunbeckia Sophia Yellow' plants. The monthly application of microbiological preparations adhered to the concentrations recommended by producers. Post-storage evaluations included shoot and root parameters, leaf morphology, and chlorophyll biosynthesis. All microbiological preparations positively influenced shoot elongation in B. macrophylla 'Silver Heart'. The microbiological treatments stimulated root development in this species, i.e., increased root length, area, volume, and the number of root forks and tips. In E. purpurea 'Secret Glow', all three preparations enhanced shoot length, leaf parameters, and root traits, with Guard demonstrating the highest efficacy. As for P. amplecicaulis 'JS Caliente', BactoFungiStop negatively affected shoot and leaf parameters but promoted root development. Heuchera × hybrida 'Northern Exposure Red' exhibited increased shoot and leaf dimensions with all microbiological treatments, while Rudbeckia × hybrida 'Sunbeckia Sophia Yellow' displayed positive responses in shoot-related traits but no impact on root development. None of the microbiological preparations influenced chlorophyll biosynthesis in any of the studied species. The results of our research can be implemented in the large-scale production of ornamental plants. [ABSTRACT FROM AUTHOR]

Rhizobium plays an important role in cultivation of legumes throughout the nitrogen fixation process. In the present study, the growth of alfalfa (Medicago sativa) was studied after treatment with Rhizobium spp. isolated from two different sites in Jordan. The effect of the two isolates (RS1 and RS2) and co-inoculation of the two isolates (RS1+RS2) was tested on alfalfa. Chlorophyll contents, relative water content, leaf area, shoot length, stem diameter and plant biomass (leaf, root and shoot dry weight) were studied under growth chamber conditions (day/night temperatures of 25°C; 16:8 h photoperiod) using different inoculum doses (10 ml, 20 ml and 40 ml). The effect of Rhizobium isolates on alfalfa was compared with rhizosphere plant growth-promoting rhizobacteria (PGPR) collected from the same soil samples. The results indicated that RS1 at high dose (40 ml) and RS2 at any dose significantly enhanced alfalfa growth in all measured parameters compared with control plants (without bacterial inoculation). RS2 was better than RS1 in most measured parameters even at low inoculum dose (10 ml), whereas no significant differences between the two strains were found at high inoculum doses. Co-inoculation of the two isolates was less effective than each isolate alone. On the other hand, the PGPR showed a significant enhancement of alfalfa growth as they enhanced significantly all measured parameters compared to the control plants at all doses. [ABSTRACT FROM AUTHOR]

Late leaf spot of groundnuts is caused by the fungal pathogen Cercosporidium personatum. Efforts to prevent this disease generally use synthetic fungicides that can pollute the environment. This study aims to identify the fungal pathogen of groundnut late leaf spot and determine the antifungal effect of leaf extract from several plants on leaf spot disease suppression. Late leaf spot pathogen was identified based on hyphae and conidia morphological characteristics. Growth inhibition of leaf extracts from butterfly pea (Clitoria ternatea), Mexican sunflower (Tithonia diversifolia), basil (Ocimum gratissimum), and sugar apple (Annona squamosa) at aconcentration of 25%were tested against C. personatum in vitro. The growth and intensity of groundnut disease attackswere assessed for seven weeks by inoculating C. personatum and applied with several leaf extracts. Results showed that the pathogen was identified as C. personatum with conidia characteristics of cylindrical to obclavate, short and slightly curved with four septa, and 35.75 × 7.11 µm in size. The inhibition percentage of C. personatum in vitro reached 94.03% by leaf extract of C. ternatea, 88.56% by T. diversifolia, 87.20% by O. gratissimum, and 84.10% by A. squamosa. Treatment of C. ternatea increased plant height by up to 12.85% and showed the highest reduction of infected leaves by up to 61.53%. C. ternatea leaf extract was found to be the most effective leaf extract to suppress C. personatum infection by 77.94%, while T. diversifolia, O. gratissimum, and A. squamosa reduced disease severity by 70.15%, 65.43%, and 57.76%, respectively. [ABSTRACT FROM AUTHOR]

The objective of the study is to investigate the mechanism by which summer pruning enhances the growth of pepper plants, as indicated by growth and fruit appearance indicators, photosynthetic rate and gas exchange parameters, rapid light response and induction kinetics curves and the related chlorophyll fluorescence parameters. The results indicated that the leaf growth rate, the individual pepper fruit weight, and the fruit longitudinal and cross diameters of the pruned group were significantly higher than those of the control. The stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) of the pruned group were significantly higher than those of the control. The initial slope of the rapid light response curve, which represents light energy utilisation efficiency (a), the maximum electron transfer rate (Jmax) and saturated light intensity (PARsat) were all higher in the summer pruning group than in the control group. The F0 of the pruned group decreased by 16.83%, Fv/F0 increased by 23.69%, PIabs increased by 58.33%, and DIo/RC decreased by 22.09% compared to the control group. In summary, summer pruning significantly improves the leaf growth rate and fruit appearance quality of pepper, effectively promotes the photosynthesis of functional leaves, and reduces the degree of stress under adverse environmental conditions. [ABSTRACT FROM AUTHOR]

Twenty-five years ago, a seminal paper demonstrated that warm temperatures increase auxin levels to promote hypocotyl growth in Arabidopsis thaliana. Here we highlight recent advances in auxin-mediated thermomorphogenesis and identify unanswered questions. In the warmth, PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF7 bind the YUCCA8 gene promoter and, in concert with histone modifications, enhance its expression to increase auxin synthesis in the cotyledons. Once transported to the hypocotyl, auxin promotes cell elongation. The meta-analysis of expression of auxin-related genes in seedlings exposed to temperatures ranging from cold to hot shows complex patterns of response. Changes in auxin only partially account for these responses. The expression of many SMALL AUXIN UP RNA (SAUR) genes reaches a maximum in the warmth, decreasing towards both temperature extremes in correlation with the rate of hypocotyl growth. Warm temperatures enhance primary root growth, the response requires auxin, and the hormone levels increase in the root tip but the impacts on cell division and cell expansion are not clear. A deeper understanding of auxin-mediated temperature control of plant architecture is necessary to face the challenge of global warming. [ABSTRACT FROM AUTHOR]

Coal mining is generally carried out through open pit mining methods which have an impact and become an obstacle to changes in the chemical, physical, and biological properties of the soil. Revegetation of reclaimed land is a priority in restoring ecosystems disrupted by mining activities. This study aims to assess the success of the direct planting method in accelerating the growth of Pterocarpus indicus plants in coal mining reclamation areas. Field data and observations are used to evaluate the growth of plants directly planted in reclaimed post-mining land. The growth parameters observed include plant height, stem diameter, and leaf count using both seedling and stemcutting planting materials. The research results indicate that the direct planting method has a significant impact on accelerating the growth of Pterocarpus indicus plants. The plant height, diameter, and leaf count growth from the ANOVA test results showed a significant effect or significance at p<0.05 for the interaction between planting material, fertilizer, and dosage. The Duncan test results for the average plant height, stem diameter, and leaf count indicate the optimal use of bokashi fertilizer. The effective bokashi fertilizer dosage for each variable is 3 kg/planting hole, resulting in a plant height of 102.31 cm; 3 kg/planting hole, resulting in a stem diameter of 24.26 cm; and 5 kg/planting hole, resulting in a leaf count of 41.32. [ABSTRACT FROM AUTHOR]

Kentucky bluegrass (Poa pratensis L.) cultivars are diverse in their phenotype with a common classification system used to describe their growth habit but it is unclear why their growth differs. Growth analysis measurements have been used to explain growth rate differences among grass species and cultivars. The objective of this experiment was to study the growth of six commercially available Kentucky bluegrass cultivars from different growth habit classifications using classical growth analysis. Kentucky bluegrass seed was germinated and transplanted into cone‐tainers and transferred to a growth chamber maintained at 25/15°C (day/night) and a 12‐h photoperiod. Thirty plants per cultivar were used with six whole plants of each cultivar harvested 8 weeks after transplanting and once per week for the next 4 weeks for a total of five harvests. Barvette HGT produced the largest plants, and Moonlight SLT produced the smallest plants by the end of the experiment, although the relative growth rate and absolute growth rate did not vary between the cultivars. Results from the growth analysis revealed that Moonlight SLT had the highest leaf area ratio (89.4 cm2 g−1), specific leaf area (200.1 cm2 g−1), and rhizome weight ratio (0.101 g g−1), but the lowest stem weight ratio (0.120 g g−1) and root weight ratio (0.338 g g−1). Final plant weights and leaf area measurements were closely aligned with Kentucky bluegrass classification information. Unfortunately, classical growth analysis provided little insight into why some cultivars possess more aggressive growth characteristics or compact growth habits. Core Ideas: Modern Kentucky bluegrass cultivars used for turfgrass had similar relative growth rates.Whole plant mass and leaf area measurements were consistent with Kentucky bluegrass growth habit classifications.Classical growth analysis provided little insight into why some cultivars grow more aggressively than others. [ABSTRACT FROM AUTHOR]

Background and Aims Plasticity of leaf growth and photosynthesis is an important strategy of plants to adapt to shading stress; however, their strategy of leaf development to achieve a simultaneous increase in leaf area and photosynthesis under shading remains unknown. Methods In the present study, a pot experiment was conducted using three rapeseed genotypes of Huayouza 50 (HYZ50), Zhongshuang 11 (ZS11) and Huayouza 62 (HYZ62), and the responses of plant growth, leaf morphoanatomical traits, cell wall composition and photosynthesis to shading were investigated. Key Results Shading significantly increased leaf area per plant (LA plant) in all genotypes, but the increase in HYZ62 was greater than that in HYZ50 and ZS11. The greater increment of LA plant in HYZ62 was related to the larger decrease in leaf mass per area (LMA) and leaf density (LD), which were in turn related to less densely packed mesophyll cells and thinner cell walls (T cw). Moreover, shading significantly increased photosynthesis in HYZ62 but significantly decreased it in HYZ50. The enhanced photosynthesis in HYZ62 was related to increased mesophyll conductance (g m) due primarily to thinner cell walls. Conclusions The data presented indicate that the different plasticity of mesophyll cell density, cell wall thickness and cell wall composition in response to shading can dramatically affect leaf growth and photosynthesis. [ABSTRACT FROM AUTHOR]

The aim of the study was to examine the effects of application of plant-growth regulators (PGR) on the growth of paulownia plants and evaluate their usefulness in paulownia nurseries. The experiment was carried out on the paulownia interspecific hybrid (Paulownia elongata × Paulownia fortunei) 'Oxytree'. Micropropagated plants grown in pots were sprayed with PGR solutions. Gibberellins (GA3, GA4+GA7), 6-benzyladenine (BA), triclopyr (TPA), ethephon (ETH), daminozide (DA), prohexadione-Ca (PH), and trinexapac-ethyl (TE) were used. They were included in commercial products (Florgib 245 mg dm−3, Gibb plus 11 SL 5 cm3 dm−3, Globaryll 100 SL 1.5 cm3 dm−3, Topper 10 ST 200 mg dm−3, Agrostym 480 SL 2 cm3 dm−3, B-Nine 85 SG 2 g dm−3, Regalis plus 10 WG 2.5 g dm−3, Moddus 250 EC 1 cm3 dm−3, respectively). None of the studied preparations modified positive correlations between the longitudinal vs. transverse growth of stems and growth of leaves. Not only GA3, GA4+GA7, but also BA (cytokinin) and unexpectedly TE (retardant) stimulated stem elongation and thickening. Furthermore, the effect of TE lasted longer than influence of GAx and BA. Leaves of TE-treated plants were distinguished by a higher chlorophyll a/b ratio, and a lower relative chlorophyll content and efficiency of photosystem II (Fv/Fm, Fv/F0). TPA strongly deformed the stems and leaves of liners. Other regulators (ETH, DA, PH) retarded the diameter growth of stems and leaf expansion. Some results obtained by GAx, BA, and especially by TE treatment, might be beneficial for paulownia grown as ornamental and/or timber tree. [ABSTRACT FROM AUTHOR]

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Studying intraspecific variation in multistress responses is central for predicting and managing the population dynamics of wild plant species under rapid global change. Yet, it remains a challenging goal in this field to integrate knowledge on the complex biochemical underpinnings for the targeted 'non-model' species. Here, we studied divergence in combined drought and heat responses among Northern and Southern European populations of the dune plant Cakile maritima , by combining comprehensive plant phenotyping with metabolic profiling via FT-ICR-MS and UPLC-TQ-MS/MS. We observed pronounced constitutive divergence in growth phenology, leaf functional traits, and defence chemistry (glucosinolates and alkaloids) among population origins. Most importantly, the magnitude of growth reduction under drought was partly weaker in southern plants and associated with divergence in plastic growth responses (leaf abscission) and the modulation of primary and specialized metabolites with known central functions not only in plant abiotic but also in biotic stress responses. Our study indicates that divergent selection has shaped the constitutive and drought-/heat-induced expression of numerous morphological and biochemical functional traits to mediate higher abiotic stress resistance in southern Cakile populations, and highlights that metabolomics can be a powerful tool to explore the underlying mechanisms of local adaptation in 'non-model' species. [ABSTRACT FROM AUTHOR]

Plant organ growth results from the combined activity of cell division and cell expansion. The co-ordination of these two processes depends on the interplay between multiple hormones that determine the final organ size. Using the semidominant Hairy Sheath Frayed1 (Hsf1) maize mutant that hypersignals the perception of cytokinin (CK), we show that CK can reduce leaf size and growth rate by decreasing cell division. Linked to CK hypersignaling, the Hsf1 mutant has an increased jasmonic acid (JA) content, a hormone that can inhibit cell division. The treatment of wild-type seedlings with exogenous JA reduces maize leaf size and growth rate, while JA-deficient maize mutants have increased leaf size and growth rate. Expression analysis revealed the increased transcript accumulation of several JA pathway genes in the Hsf1 leaf growth zone. A transient treatment of growing wild-type maize shoots with exogenous CK also induced the expression of JA biosynthetic genes, although this effect was blocked by the co-treatment with cycloheximide. Together, our results suggest that CK can promote JA accumulation, possibly through the increased expression of specific JA pathway genes. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal (AM) fungi enhance plant stress tolerance, but it is unclear whether AM fungi affect heat tolerance in cucumbers. This study aimed to analyze how an AM fungus, Diversispora versiformis, affected growth, chlorophyll, five osmolytes, and plasma membrane intrinsic proteins (PIPs) and heat shock protein 70 (Hsp70) gene expression in cucumber leaves after a short-term (80 h) heat stress. Heat treatment significantly reduced root AM fungal colonization rate (0.26 folds). Heat treatment also distinctly suppressed plant height, stem diameter, and biomass, whereas AM fungal inoculation improved these growth variables as well as the chlorophyll index, with the benefit being more obvious under heat than under no-heat stress conditions. Heat treatment triggered differential changes in osmolytes (sucrose, fructose, and betaine) of inoculated and uninoculated cucumbers, whereas inoculation with AM fungus significantly raised leaf sucrose, fructose, glucose, betaine, and proline levels when compared to non-AM fungal inoculation. Heat treatment increased the expression of two (CsPIP1;6 and CsPIP2;1) of eight CsPIPs in inoculated and uninoculated plants, whereas AM fungal inoculation up-regulated the expression of CsPIP1;6, CsPIP2;1, and CsPIP2;6 under heat stress conditions. Hsp70s expressed differently in inoculated and uninoculated plants under heat versus no-heat stress, with 6 of 11 CsHsp70s down-regulated in inoculated plants. Under heat stress conditions, AM fungus only up-regulated CsHsp70-8 expression in 11 Hsp70s, while another eight CsHsp70s were down-regulated. Heat treatment and AM fungal inoculation both increased the expression of CsHsp70-8 and CsPIP1;6. It was concluded that AM fungus-inoculated cucumbers have high levels of growth, chlorophyll, and osmolytes under heat stress and do not require high CsPIPs and CsHsp70s expression to tolerate a short-term heat treatment. [ABSTRACT FROM AUTHOR]

【Objective】 The purpose was to study the effects of nitrogen application and leaves retention on the yield and quality of yellow sun-cured tobacco. 【Method】 Using the yellow sun-cured tobacco variety ‘Cunsanpi’ as the material, a split-area experimental design was adopted, and the two-factor experiments of nitrogen application of 82.5, 97.5, 112.5 and 127.5 kg/hm² and the number of leaves retained of 16, 19 and 22 leaves/plant (Total 12 treatments) were conducted to study its effects on the agronomic traits, yield, average price, yield value and appearance quality of yellow sun-cured tobacco. 【Result】 The results showed that increased nitrogen fertilization could promote the growth of tobacco plant and increase nitrogen metabolism, and at the same time, it was conducive to the improvement of agronomic traits such as stem girth, pitch, leaf length and width, and leaf area. Within a certain range of nitrogen application, tobacco yield increased with the increase in the number of leaves retained. Within a certain range of the number of leaves, the tobacco yield varied with the nitrogen application. When the number of leaves was 16 leaves/plant and 22 leaves/plant, the tobacco yield showed an upward trend with the increase of nitrogen application. When the number of retained leaves was 19 leaves/plant and the applied nitrogen ranged from 82.5 kg/hm² to 112.5 kg/hm², the tobacco yield increased with the increase of applied nitrogen. From the same level of nitrogen application of different number of leaves of tobacco leaf yield changes, when the nitrogen application of 127.5 kg/hm², the tobacco yield with the increase in the number of leaves of tobacco leaf is a downward trend. When the nitrogen application was 112.5 kg/hm² and the number of retained leaves was 19 leaves/plant, the tobacco leaf yield value was the highest, which was 54 567.00 yuan/hm². When the nitrogen applications were 82.5 kg/hm² and 97.5 kg/hm², the tobacco leaf yield value increased with the increase of the number of retained leaves. From the point of view of the average price of tobacco with different number of leaves of the same nitrogen application, when the nitrogen application was 82.5 kg/hm² and 127.5 kg/hm², the average price of tobacco showed a decreasing trend with the increase of the number of leaves of the same application. When the N application was 97.5 kg/hm², the average price of tobacco leaf increased with the increase of the number of retained leaves. When the nitrogen application was 112.5 kg/hm², the average price of tobacco leaf increased and then decreased with the number of leaves retained, and was higher in the treatment with 19 leaves/plant. The appearance quality of tobacco leaf was better in three treatments: 82.5 kg/hm² of nitrogen application, 16 leaves/plant; 97.5 kg/hm² of nitrogen application, 22 leaves/plant and 127.5 kg/hm² of nitrogen application, 19 leaves/plant. 【Conclusion】 Under the conventional cultivation condition of ensuring density of 15 150 plants/hm², applying nitrogen at 112.5 kg/hm² and retaining leaves at 19 leaves/plant, the yellow sun-cured tobacco variety ‘Cunsanpi’ could obtain better economic benefits in Fuquan, Guizhou. [ABSTRACT FROM AUTHOR]

Phytohormones are key signalling molecules in developing responses in plants with various biotic and abiotic stresses. From the catalogue of well-known classical plant hormones, Jasmonic acid (JA) and its corresponding precursors and derivatives attract massive research attention by acting as potential methods for improving tolerance in diseased plants. Jasmonates are oxylipins chiefly derived from α-linolenic acids through the octadecanoid pathway. Plants synthesise this hormone in response to growth or defence-linked signs to coordinate plant development, growth or defence against numerous pathogenic microorganisms. Several reports emphasise the contribution of JAs in regulating vital physiological processes such as leaf senescence, tuber formation, photosynthesis, reproduction, seed germination and growth inhibition in plants. In response to pathogen exposure, JAs assume their operational task as a 'master switch', in charge of the initiation of signal transduction cascade, participating in the upregulation of genes associated with the production of alkaloids and phytoalexin, synthesis and accumulation of storage proteins, cell wall components and most importunately—stress ameliorative agents. This review focuses on recent findings connected to the structure, biosynthesis, regulation and signalling systems of JAs. In addition to this, the present article gives an essential insight into how the application of this phytohormone is involved in stress amelioration and induction of pathogenesis-resistant genes from an agriculturist, plant physiologist and biotechnologist's point of view. [ABSTRACT FROM AUTHOR]

Plant senescence is mediated by complex regulatory pathways. Any delay in the onset of senescence is linked with improved plant growth and fitness. In this work, we identified Solanum lycopersicum ACAULIS5 (SlACL5) gene, a close homolog of Arabidopsis thaliana ACAULIS5 (AtACL5), which shows higher expression in developing leaves, stem, and roots of tomato plants. We also observed that its expression was gradually decreased from young and mature leaves to leaves undergoing senescence. We demonstrated that its constitutive overexpression (35S::SlACL5) in Nicotiana tabacum resulted in increased plant growth and higher accumulation of pigments and delayed the senescence of leaves. We found that the average length of plants of 35S::SlACL5 OE lines was higher than the control plants. The anatomy of the stem of OE lines showed no major alterations in cortical and vascular tissues. However, the expression of xylem cell death marker NtMC9 was downregulated in these lines indicating delayed xylem cell death program. Furthermore, we observed that expression of early-stage and late-stage senescence-associated marker genes, NtSGR1 and NtSAG12 was greatly reduced in the leaves of OE lines showing delayed senescence process in the leaves. We show that OE plants have reduced levels of Reactive Oxygen Species (ROS) and activity of some of the antioxidant enzymes was reduced or misregulated. The MDA content was also found to be less in these lines. Relative chloroplast DNA (cpDNA) content and marker gene expression analysis also performed which show higher cpDNA content and increased expression of chloroplast marker genes, NtrpoA, NtrbcL, and NtpetB in OE lines suggesting higher chloroplast activity in OE lines than the control. We conclude that overexpression of SlACL5 in tobacco leads to altered plant development, higher chloroplast activity and chlorophyll contents, reduced ROS generation, and downregulated expression of senescence-associated marker genes, thereby delaying leaf senescence program which resulted in vigorous plant growth. [ABSTRACT FROM AUTHOR]

Inherently, ammonium (NH4+) is critical for plant growth; however, its toxicity suppresses potassium (K+) uptake and vice-versa. Hence, attaining a nutritional balance between these two ions (NH4+ and K+) becomes imperative for the growth of tobacco seedlings. Therefore, we conducted a 15-day experimental study on tobacco seedlings exposed to different concentrations (47 treatments) of NH4+/K+ at different corresponding 12 ratios simultaneously in a hydroponic system. Our study aimed at establishing the optimal NH4+-K+ concentration and the corresponding ratio required for optimal growth of different tobacco plant organs during the seedling stage. The controls were the baseline for comparison in this study. Plants with low or excessive NH4+-K+ concentration had leaf chlorosis or dark greenish colouration, stunted whole plant part biomass, and thin roots. We found that adequate K+ supply is a pragmatic way to mitigate NH4+-induced toxicity in tobacco plants. The optimal growth for tobacco leaf and root was attained at NH4 +-K+ concentrations 2-2 mM (ratio 1:1), whereas stem growth was optimal at NH4+-K+ 1-2 mM (1:2). The study provided an insight into the right combination of NH4+/K+ that could mitigate or prevent NH4+ or K+ stress in the tobacco seedlings. [ABSTRACT FROM AUTHOR]

The effects of the bioherbicidal activity of the fungal phytopathogen, Albifimbria verrucaria (AV), formerly Myrothecium verrucaria, on glyphosate-resistant and –susceptible Conyza canadensis (horseweed) were examined in greenhouse and field studies. Spray applications of mycelial formulations of AV infected both glyphosate-resistant and -susceptible C. canadensis plants at various growth stages. Young plants in the rosette leaf stage of growth were controlled more efficaciously than were older plants that had bolted or that were in the inflorescence stage; nevertheless, severe injury and mortality also occurred in mature plants. The results indicate that this bioherbicidal fungus can infect and control C. canadensis, thereby demonstrating the potential of this fungus as a bioherbicidal agent against this troublesome weed, which has become resistant to various herbicides. [ABSTRACT FROM AUTHOR]

Greenhouses provide a controlled environment where temperature, humidity, and light can be optimized for tomato growth. The present study was carried out to estimate the growth, biochemical, and physiological responses of cherry tomatoes to some environmental conditions. Data was collected on different dates during the period extending from December 2022 to March 2023. Based on collected data, the potential growth rate of plants has been predicted: plant height, 2.43 cm/day to 2.98 cm/day; leaf growth, 0017 cm/day; three leaves per week. Plants with a high day length were high in height and produced more leaves. A significant relationship found between the inflorescence and the data collected for total mass/inflorescence, average size of fruits/inflorescence, diameter of fruit/inflorescence, and fruit height/inflorescence. A non-significant interaction found between the fruit keeping quality, fruit size, and inflorescence number. Regarding their biochemical responses, every inflorescence differs significantly from the others. A nonsignificant relationship was also found between fruit acidity and inflorescence order. The current study confirms a direct relationship between biochemical, growth, and productivity indicator under greenhouse conditions. An analysis of variance was used to statistically assess the collected data at a confidence level of p 0.05. [ABSTRACT FROM AUTHOR]

Auxin is well known to stimulate coleoptile elongation and rapid seedling growth in the air. However, its role in regulating rice germination and seedling establishment under submergence is largely unknown. Previous studies revealed that excessive levels of indole‐3‐acetic acid(IAA) frequently cause the inhibition of plant growth and development. In this study, the high‐level accumulation of endogenous IAA is observed under dark submergence, stimulating rice coleoptile elongation but limiting the root and primary leaf growth during anaerobic germination (AG). We found that oxygen and light can reduce IAA levels, promote the seedling establishment and enhance rice AG tolerance. miRNA microarray profiling and RNA gel blot analysis results show that the expression of miR167 is negatively regulated by submergence; it subsequently modulates the accumulation of free IAA through the miR167‐ARF‐GH3 pathway. The OsGH3‐8 encodes an IAA‐amido synthetase that functions to prevent free IAA accumulation. Reduced miR167 levels or overexpressing OsGH3‐8 increase auxin metabolism, reduce endogenous levels of free IAA and enhance rice AG tolerance. Our studies reveal that poor seed germination and seedling growth inhibition resulting from excessive IAA accumulation would cause intolerance to submergence in rice, suggesting that a certain threshold level of auxin is essential for rice AG tolerance. Summary statement: Excessive auxin accumulation negatively affects rice AG. Conversely, oxygen and light significantly reduce IAA levels, promote the seedling establishment during AG, and submergence‐repressed miR167 reduces IAA levels through miR167‐ARF‐GH3 pathway and enhances AG tolerance. [ABSTRACT FROM AUTHOR]

Young leaves of Artemisia princeps Pamp. (Japanese mugwort), already used as a foodstuff in Japan, can be positioned as a functional health food because of remarkably higher contents of chlorogenic acid and total polyphenol compared to common vegetables. To procure young leaves in demand on a yearround basis by hydroponic production in fully artificial lighttype plant factories, we investigated whether 24h photoperiod, known to enhance some beneficial constituents, could improve the growth and chemical constituents of Japanese mugwort plants grown hydroponically in a plant factory condition. As we previously demonstrated that lowering the nutrient solution concentration increased chlorogenic acid and total polyphenol contents of the leaves without reducing the growth, plants were cultivated with a lower concentration of nutrient solution. The results indicated that it is possible to grow Japanese mugwort hydroponically under 24h photoperiod in a plant factory condition with a nutrient solution concentration as low as 25% of the standard. In addition, under 24h photoperiod, plant growth was greatly accelerated and chlorogenic acid as well as total polyphenol were increased, suggesting that 24h photoperiod is highly beneficial for Japanese mugwort production in a fully artificial lighttype plant factory. [ABSTRACT FROM AUTHOR]

Coffee (Coffea arabica L.) plants have been assorted as highly suitable to growth at elevated [CO2] (eCa), although such suitability is hypothesized to decrease under severe shade. We herein examined how the combination of eCa and contrasting irradiance affects growth and photosynthetic performance. Coffee plants were grown in open-top chambers under relatively high light (HL) or low light (LL) (9 or 1 mol photons m−2 day−1, respectively), and aCa or eCa (437 or 705 μmol mol–1, respectively). Most traits were affected by light and CO2, and by their interaction. Relative to aCa, our main findings were (i) a greater stomatal conductance (gs) (only at HL) with decreased diffusive limitations to photosynthesis, (ii) greater gs during HL-to-LL transitions, whereas gs was unresponsive to the LL-to-HL transitions irrespective of [CO2], (iii) greater leaf nitrogen pools (only at HL) and higher photosynthetic nitrogen-use efficiency irrespective of light, (iv) lack of photosynthetic acclimation, and (v) greater biomass partitioning to roots and earlier branching. In summary, eCa improved plant growth and photosynthetic performance. Our novel and timely findings suggest that coffee plants are highly suited for a changing climate characterized by a progressive elevation of [CO2], especially if the light is nonlimiting. [ABSTRACT FROM AUTHOR]

Plant growth and development are correlated with many aspects, including phytohormones, which have specific functions. However, the mechanism underlying the process has not been well elucidated. Gibberellins (GAs) play fundamental roles in almost every aspect of plant growth and development, including cell elongation, leaf expansion, leaf senescence, seed germination, and leafy head formation. The central genes involved in GA biosynthesis include GA20 oxidase genes (GA20oxs), GA3oxs, and GA2oxs, which correlate with bioactive GAs. The GA content and GA biosynthesis genes are affected by light, carbon availability, stresses, phytohormone crosstalk, and transcription factors (TFs) as well. However, GA is the main hormone associated with BR, ABA, SA, JA, cytokinin, and auxin, regulating a wide range of growth and developmental processes. DELLA proteins act as plant growth suppressors by inhibiting the elongation and proliferation of cells. GAs induce DELLA repressor protein degradation during the GA biosynthesis process to control several critical developmental processes by interacting with F-box, PIFS, ROS, SCLl3, and other proteins. Bioactive GA levels are inversely related to DELLA proteins, and a lack of DELLA function consequently activates GA responses. In this review, we summarized the diverse roles of GAs in plant development stages, with a focus on GA biosynthesis and signal transduction, to develop new insight and an understanding of the mechanisms underlying plant development. [ABSTRACT FROM AUTHOR]

Leaves comprise one of the most important organs for plant growth and development. Although there have been some reports on leaf development and the establishment of leaf polarity, their regulatory mechanisms are not very clear. In this study, we isolated a NAC (NAM, ATAF, and CUC) transcription factor (TF), i.e., IbNAC43, from Ipomoea trifida, which is a wild ancestor of sweet potato. This TF was highly expressed in the leaves and encoded a nuclear localization protein. The overexpression of IbNAC43 caused leaf curling and inhibited the growth and development of transgenic sweet potato plants. The chlorophyll content and photosynthetic rate in transgenic sweet potato plants were significantly lower than those in wild-type (WT) plants. Scanning electron microscopy (SEM) and paraffin sections showed that the ratio of cells in the upper and lower epidermis of the transgenic plant leaves was unbalanced; moreover, the abaxial epidermal cells were irregular and uneven in transgenic plants. In addition, the xylem of transgenic plants was more developed than that of WT plants, while their lignin and cellulose contents were significantly higher than those of WT. Quantitative real-time PCR (qRT-PCR) analysis showed that the overexpression of IbNAC43 upregulated the genes involved in leaf polarity development and lignin biosynthesis in transgenic plants. Moreover, it was found that IbNAC43 could directly activate the expression of the leaf adaxial polarity-related genes IbREV and IbAS1 by binding to their promoters. These results indicate that IbNAC43 might play a critical role in plant growth by affecting the establishment of leaf adaxial polarity. This study provides new insights regarding leaf development. [ABSTRACT FROM AUTHOR]

Background: Silica nanoparticles (SiNPs) have been demonstrated to have beneficial effects on plant growth and development, especially under biotic and abiotic stresses. However, the mechanisms of SiNPs-mediated plant growth strengthening are still unclear, especially under field condition. In this study, we evaluated the effect of SiNPs on the growth and sugar and hormone metabolisms of wheat in the field. Results: SiNPs increased tillers and elongated internodes by 66.7% and 27.4%, respectively, resulting in a larger biomass. SiNPs can increase the net photosynthetic rate by increasing total chlorophyll contents. We speculated that SiNPs can regulate the growth of leaves and stems, partly by regulating the metabolisms of plant hormones and soluble sugar. Specifically, SiNPs can increase auxin (IAA) and fructose contents, which can promote wheat growth directly or indirectly. Furthermore, SiNPs increased the expression levels of key pathway genes related to soluble sugars (SPS, SUS, and α-glucosidase), chlorophyll (CHLH, CAO, and POR), IAA (TIR1), and abscisic acid (ABA) (PYR/PYL, PP2C, SnRK2, and ABF), whereas the expression levels of genes related to CTKs (IPT) was decreased after SiNPs treatment. Conclusions: This study shows that SiNPs can promote wheat growth and provides a theoretical foundation for the application of SiNPs in field conditions. [ABSTRACT FROM AUTHOR]

Salicylic acid and Azospirillum brasilense stimulate plant growth and productivity. In some environments, plant physiology similarly responds to both bioactive products. Considering this, a field experiment was conducted to study the physiological effect of Salicilic acid and A. brasilense on growth and grain yield of maize plants. The experiment involved three treatments consisting of imbibed seeds in an aqueous solution of SA (0.01 mM), inoculated seeds with A. brasilense and a control treatment. Seed imbibition in SA and inoculation with A. brasilense improved vegetative growth in the early stages of crop ontogeny, increasing leaf growth, plant height, stem diameter and biomass accumulation. Spikelet length and weight were greater in plants first inoculated with A. brasilense and then treated with SA. Results indicated that SA stimulated biomass partitioning towards leaves, root and stem, while A. brasilense mainly affected leaf growth, plant height, ear dimensions and grain yield. Such results turn crucial for biological fertilization strategies aimed at reducing pollutant loads that accompany chemical fertilizers. Both products can be part of maize management practices given competitive economic advantages and sustainability. [ABSTRACT FROM AUTHOR]

Callose, mainly deposited at the cell plate and in the newly formed cell wall at a very low level, is critical for cell activity and growth in plants. The genetic control and function of callose synthases, responsible for the synthesis of callose, are largely unknown in maize. In this study, we cloned a maize callose synthase, SLM1 (Seedling Lethal Mutant1) encoding for a GLUCAN SYNTHASE-LIKE (GSL) gene, from a seedling lethal mutant. Three different point mutations confirmed the key role of SLM1 to maintain maize normal growth. SLM1 was specifically expressed in immature leaf vascular with an enrichment in phloem of developing vasculature. Consistently, slm1 had severe defects in vasculature and leaf development, and terminated growth about 2 weeks after germination. Thus, SLM1 is a key gene to maintain normal growth by controlling leaf vascular development and cell activities. Loss of SLM1 function interrupted severely the important signaling pathways in which cell cyclin and histone related genes are involved. Our study reveals the critical function of a maize GSL gene and also its downstream signaling to maintain a normal growth of maize. [ABSTRACT FROM AUTHOR]

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Polarimetry is a powerful characterization technique that uses a wealth of information from electromagnetic waves, including polarization. Using the rich information provided by polarimetry, it is being actively studied in biomedical fields such as cancer and tumor diagnosis. Despite its importance and potential in agriculture, polarimetry for living plants has not been well studied. A Stokes polarimetric imaging system was built to determine the correlation between the polarization states of the light passing through the leaf and the growth states of lettuce. The Stokes parameter s3 associated with circular polarization increased over time and was strongly correlated with the growth of lettuce seedlings. In the statistical analysis, the distribution of s3 followed the generalized extreme value (GEV) probability density function. Salt stress retarded plant growth, and the concentration of treated sodium chloride (NaCl) showed a negative correlation with the location parameter μ of GEV. The clear correlation reported here will open the possibility of polarization measurements on living plants, enabling real-time monitoring of plant health. [ABSTRACT FROM AUTHOR]

AINTEGUMENTA-LIKE (AIL) transcription factors are widely studied and play crucial roles in plant growth and development. However, the functions of the AIL family in legume species are largely unknown. In this study, 11 MtAIL genes were identified in the model legume Medicago truncatula, of which four of them are MtANTs. In situ analysis showed that MtANT1 was highly expressed in the shoot apical meristem (SAM) and leaf primordium. Characterization of mtant1 mtant2 mtant3 mtant4 quadruple mutants and MtANT1-overexpressing plants revealed that MtANTs were not only necessary but also sufficient for the regulation of leaf size, and indicated that they mainly function in the regulation of cell proliferation during secondary morphogenesis of leaves in M. truncatula. This study systematically analyzed the MtAIL family at the genome-wide level and revealed the functions of MtANTs in leaf growth. Thus, these genes may provide a potential application for promoting the biomass of legume forages. [ABSTRACT FROM AUTHOR]

Climate change can profoundly alter volatile organic compound (VOC) emissions from vegetation and thus influence climate evolution. Yet, the short- and long-term effects of elevated CO 2 concentrations on emissions in interaction with temperature are not well enough understood, especially for VOCs other than isoprene. To gain additional insight, we conducted a study on holm oak, which is known for its strong foliar monoterpene emissions that are directly linked to their synthesis. We measured CO 2 -response curves of emissions, CO 2 –H 2 O gas exchanges and chlorophyll fluorescence at two assay temperatures (30 and 35 ∘ C) on saplings of four populations grown under normal and double CO 2 concentrations combined with two temperature growth regimes differing by 5 ∘ C (day/night: 25/15 and 30/20 ∘ C). A stepwise reduction in CO 2 resulted in a decrease in emissions, occasionally preceded by an increase, with the overall decrease in emissions being greater at 35 ∘ C than at 30 ∘ C assay temperature. During ramping to high CO 2 , emissions remained mostly unchanged at 35 ∘ C, whereas at 30 ∘ C they often dropped, especially at the highest CO 2 levels (≥ 1200 ppm). In addition to the actual leaf temperature, the high CO 2 responsiveness of emissions was modulated by the plant's growth temperature with warm-grown plants being more sensitive than cool-grown plants. In contrast, growth CO 2 had no significant effect on the CO 2 sensitivity of emissions, although it promoted plant growth and the leaf emission factor. Correlation analyses suggest that the emission response to CO 2 depended primarily on the availability of energetic cofactors produced by photosynthetic electron transport. This availability was likely limited by different processes that occurred during CO 2 ramping including photooxidative stress and induction of protective and repair mechanisms as well as competition with CO 2 fixation and photorespiration. In addition, feedback inhibition of photosynthesis may have played a role, especially in leaves whose emissions were inhibited only at very high CO 2 levels. Overall, our results confirm an isoprene-analogous behavior of monoterpene emissions from holm oak. Emissions exhibit a non-linear response curve to CO 2 similar to that currently used for isoprene emission in the MEGAN model, with no difference between major individual monoterpene species and plant chemotype. Simulations estimating the annual VOC releases from holm oak leaves at double atmospheric CO 2 indicate that the observed high-CO 2 inhibition is unlikely to offset the increase in emissions due to the predicted warming. [ABSTRACT FROM AUTHOR]

Many natural objects exhibit radial or axial symmetry in a single plane. However, a universal tool for simulating and fitting the shapes of such objects is lacking. Herein, we present an R package called 'biogeom' that simulates and fits many shapes found in nature. The package incorporates novel universal parametric equations that generate the profiles of bird eggs, flowers, linear and lanceolate leaves, seeds, starfish, and tree‐rings, and three growth‐rate equations that generate the profiles of ovate leaves and the ontogenetic growth curves of animals and plants. 'biogeom' includes several empirical datasets comprising the boundary coordinates of bird eggs, fruits, lanceolate and ovate leaves, tree rings, seeds, and sea stars. The package can also be applied to other kinds of natural shapes similar to those in the datasets. In addition, the package includes sigmoid curves derived from the three growth‐rate equations, which can be used to model animal and plant growth trajectories and predict the times associated with maximum growth rate. 'biogeom' can quantify the intra‐ or interspecific similarity of natural outlines, and it provides quantitative information of shape and ontogenetic modification of shape with important ecological and evolutionary implications for the growth and form of the living world. [ABSTRACT FROM AUTHOR]

Plant acyl-CoA dominated acyltransferases (named BAHD) comprise a large appointed protein superfamily and play varied roles in plant secondary metabolism like synthesis of modified anthocyanins, flavonoids, volatile esters, etc. Tea (Camellia sinensis) is an important non-alcoholic medicinal and fragrancy plant synthesizing different secondary metabolites, including flavonoids. In the tea (C.A sinensis) cultivar Longjing 43 (LJ43), eight samples were performed into three groups for transcriptome analysis under three biological replications. Among the BAHD acyltransferase genes in tea cultivars, the expression of TEA031065 was highest in buds and young leaves following the RNA sequencing data, which was coincident with the tissue rich in catechins and other flavonoids. We then transformed this gene into wild-type Arabidopsis as an over-expression (OX) line 1 and line 2 in ½ MS media to verify its function. In the wild types (WT), the primary root length, number of secondary roots, and total root weight were significantly higher at 24%, 15%, and 53.92%, respectively, compared to the transgenic lines (OX1 and OX2). By contrast, the leaves displayed larger rosettes (21.58%), with higher total leaf weight (32.64%) in the transgenic lines than in the wild type (WT). This result is consistent with DCR mutant At5g23940 gene in Arabidopsis thaliana. Here, anthocyanin content in transgenic lines was also increased (21.65%) as compared to WT. According to the RNA sequencing data, a total of 22 growth regulatory genes and 31 structural genes with TFs (transcription factors) that are correlative with plant growth and anthocyanin accumulation were identified to be differentially expressed in the transgenic lines. It was found that some key genes involved in IAA (Auxin) and GA (Gibberellin) biosynthesis were downregulated in the transgenic lines, which might be correlated with the phenotype changes in roots. Moreover, the upregulation of plant growth regulation genes, such as UGT73C4 (zeatin), ARR15, GH3.5, ETR2, ERS2, APH4, and SAG113 might be responsible for massive leaf growth. In addition, transgenic lines shown high anthocyanin accumulation due to the upregulation of the (1) 3AT1 and (3) GSTF, particularly, GSTF12 genes in the flavonoid biosynthesis pathway. However, the TFs such as, CCoAMT, bHLH, WRKY, CYP, and other MYBs were also significantly upregulated in transgenic lines, which increased the content of anthocyanins in A. thaliana seedlings. In conclusion, a BAHD acyltransferase (TEA031065) was identified, which might play a vital role in tea growth and secondary metabolites regulation. This study increases our knowledge concerning the combined functionality of the tea BAHD acyltransferase gene (TEA031065). [ABSTRACT FROM AUTHOR]

The lengths of leaves, leaf sheaths, and internodes are the main factors affecting individual plant types. An ideotype is a basis for developing a high-yielding population structure. Water and nitrogen (N) fertilizer can directly affect the growth of a plant's organs. To evaluate the effects of irrigation and nitrogen application on the length and growth of wheat leaves, leaf sheaths, and internodes, we carried out a 5 year field experiment in the high yield wheat fields of the North China Plain. Five treatments (T2–T6) were applied, and irrigation was carried out in springtime at the appearance of the second leaf (T2), the third leaf (T3), the fourth leaf (T4), the fifth leaf (T5) and the sixth leaf (T6). The results showed that the irrigation and N topdressing periods had different effects on the leaves, leaf sheaths, and internodes. The lengths of the upper three leaves gradually increased with the progression of the irrigation and N topdressing. The increases in the lengths of the leaf sheath were similar and followed the irrigation and N topdressing pattern at four stages of leaves in the spring: n-1, n-2, n-3 and n-4. The most effective growth of the internodes was achieved by irrigation and N topdressing at the n + 2 and n + 3 stages. The vertical spacing among the upper three leaves increased with irrigation and N topdressing at the appearance of the top second (or flag) leaf. Differences in temperature and precipitation over the years either weakened or enhanced the differences in the plants' organ lengths with the different treatments. However, the orders of treatments did not alter organ length in different years. Earlier irrigation and N topdressing treatments (T2, T3, and T4) showed an inhibitory effect on the leaves and leaf sheaths during the early growth stage. The inhibitory effect was more evident in the later-emerged leaves and leaf sheaths than in those that emerged earlier. However, irrigation and N fertilization increased the final length of the organs by improving the growth rate during the rapid incremental phase (RIP) and the slow incremental phase (SIP). Although the most significant extensions of the lengths of leaves, leaf sheaths, and internodes were achieved by irrigation and N topdressing before the organs entered the RIP, the specific growth stages were different among the three organs. These results can provide a reference for directly regulating the development of wheat organs and constructing an ideotype. [ABSTRACT FROM AUTHOR]

Intercellular material transport and information transmission in plants are carried out through the plasmodesmata (PD). The amount of callose around the PD controls channel permeability. In plants, β-1,3-glucanase can degrade callose and affect plant growth and development. In this study, the gene producing PD-localized β-1,3-glucanase and regulating the leaf trichomes is identified and named PdBG4. Based on functional analysis through a series of genetic manipulation assays, we found that the high expression of PdBG4 was associated with strong PD permeability and short Arabidopsis thaliana leaf trichomes. Conversely, the low expression of PdBG4 correlated with weak PD permeability and long Arabidopsis thaliana leaf trichomes. This study revealed that the PdBG4 gene negatively modulates leaf trichome growth and development by regulating PD permeability. [ABSTRACT FROM AUTHOR]

Soils from the rhizosphere of perennial plants accumulate microorganisms that influence the growth of other plants. This microorganism biodiversity may be exploited by using these soils as an inoculum in new planting sites. Soils collected from the rhizosphere of mature Serianthes trees were subjected to treatments designed to reduce or increase microorganism populations, then were used in a series of five studies to grow Serianthes plants in container culture. Serianthes kanehirae and Serianthes grandiflora stem growth was 14–19% greater, leaf nitrogen was 40–46% greater, leaf phosphorus was 50–86% greater, and leaf potassium was 28–43% greater when grown in soils from Serianthes rhizosphere than in soils away from a Serianthes tree. Treating the Serianthes rhizosphere soils with sterilization or propiconazole fungicide reduced stem growth of S. grandiflora, S. kanehirae, and Serianthes nelsonii plants by 16–47% below that of untreated soils. The sterilization and fungicide treatments also consistently reduced phosphorus (48–50%) and potassium (12–21%) content of leaves when compared with untreated rhizosphere soil. Adding Rhizophagus irregularis inoculum to the sterilized soil reversed the reduction in S. grandiflora stem growth and leaf phosphorus content. These findings indicate that soils from the Serianthes rhizosphere contain beneficial microorganisms for Serianthes plant growth and leaf nutritional status and exploiting these soils as an inoculum for new planting sites may provide a net-positive influence on post-transplant growth and survival. [ABSTRACT FROM AUTHOR]

The genus Serianthes has not received adequate research attention, leaving large gaps in the knowledge required to inform conservation decisions. For example, nutrient management protocols are not understood due to lack of research. Serianthes grandiflora, Serianthes kanehirae, and Serianthes nelsonii plants were grown in container culture to determine the influence of increasing edaphic nitrogen (N), phosphorus (P), or potassium (K) content on stem growth and leaf nutrient relations. Addition of N alone increased leaf N, stimulated stem height and diameter growth, increased leaf number, and reduced leaf tissue concentrations of most nutrients including P and K. Addition of K alone increased leaf K, did not influence stem growth, did not reduce N or P concentration, but caused substantial changes in leaf tissue stoichiometry. Addition of P alone increased leaf P, did not influence stem growth, did not reduce leaf N or K concentration, and exerted minimal influence on concentrations and stoichiometry of other nutrients. The results indicate that single element P fertilization may be used to mitigate P deficiencies of Serianthes saplings without the risk of causing substantial nutrient imbalances. This knowledge may be used to inform nutrient management decisions in Serianthes conservation projects. [ABSTRACT FROM AUTHOR]

Vegetable grafting has been applied to fruiting crops, yet only to a limited extent in leafy greens and herbs which may also benefit from grafting. In this study, we examined the effect of reciprocal grafting two sweet basil (Ocimum basilicum L.) cultivars of differing vigor on plant growth and leaf mineral nutrient concentration to test whether differences in growth exist due to grafting and whether such differences are due to altered plant nutrient status in two trials. Two cultivars 'Nufar' (NU), a high vigor cultivar, and 'Dolce Fresca' (DF), a cultivar developed for compact growth, were selected. Four grafted treatments (scion/rootstock) were created by self-grafting (NU/NU and DF/DF) and reciprocal inter-cultivar grafting (DF/NU and NU/DF). Un-grafted plants (ug-NU and ug-DF) served as controls. Following grafting, plants were grown for 26 or 21 days in a greenhouse. DF rootstocks decreased NU shoot dry mass (19-29%) and stem length (12%) compared to ug-NU in both trials, while dry root mass was reduced (28%) in the second trial. In contrast, NU rootstocks did not affect DF growth in the first trial but significantly decreased dry shoot (18%) and root (31%) mass, compared to ug-DF in the second. Concentration of most inorganic nutrients examined was affected by both rootstock and scion genotype. For NU scions, DF rootstocks resulted in significantly higher (5-29%) levels of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, copper, and zinc in leaf tissue than ug-NU. For DF scions, NU rootstocks resulted in significantly higher (7-9%) levels of potassium and phosphorus but significantly lower (11-23%) levels of magnesium, sulfur, boron, copper, and zinc when compared to ug-DF. Results of this study show that intercultivar grafting sweet basil using a more vigorous cultivar as a rootstock did not enhance the growth of a less vigorous scion and reduced concentrations of certain nutrients. However, grafting a vigorous scion to a less vigorous rootstock reduced shoot growth but generally increased nutrient concentrations. This suggests that changes in growth in grafted basil are not due to altered nutrient status. Further research is needed to determine specific physiological processes influencing grafted basil growth. [ABSTRACT FROM AUTHOR]

Climate change can profoundly alter VOC emissions from vegetation and thus influence climate evolution. Yet, the short and long-term effects of elevated CO2 concentrations on emissions in interaction with temperature are not enough understood, especially for VOCs other than isoprene. We measured CO2-response curves of leaf monoterpene emissions and photosynthetic parameters at two assay temperatures (30 and 35°C) on four populations of holm oak saplings grown under normal and double CO2 concentrations combined with two temperature growth regimes differing by 5 °C. A stepwise reduction in CO2 resulted in a decrease in emissions, occasionally preceded by an increase, with the overall decrease in emissions being greater at 35 °C than at 30 °C assay temperature. During ramping to high CO2, emissions remained mostly unchanged at 35 °C, whereas at 30 °C they often dropped, especially at the highest CO2 levels (= 1200 ppm). In addition to the actual leaf temperature, the high CO2-responsiveness of emissions was modulated by the plant's growth temperature with warm-grown plants being more sensitive than cool-crown plants. In contrast, growth CO2 had no significant effect on emission CO2 sensitivity, although it promoted plant growth and the leaf's emission factor. Correlation analyses suggest that the emission response to low CO2 depended on the leaf's initial carbon balance and its actual energy status, whereas the response to high CO2 depended only on the leaf's actual energy status, which was affected by the occurrence of photooxidative stress and feedback limitation of photosynthesis. Overall, our results confirm an isoprene-analogous behavior of monoterpene emissions from holm oak. Emissions exhibit a nonlinear response curve similar to that currently used for isoprene emission in the MEGAN model, with no difference between major individual monoterpene species and plant chemotype. Simulations estimating annual VOC releases from holm oak leaves at double atmospheric CO2 indicate that the observed high-CO2 inhibition is unlikely to offset the increase in emissions due to expected warming. [ABSTRACT FROM AUTHOR]

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Autophagy is a highly conserved cell degradation process that widely exists in eukaryotic cells. In plants, autophagy helps maintain cellular homeostasis by degrading and recovering intracellular substances through strict regulatory pathways, thus helping plants respond to a variety of developmental and environmental signals. Autophagy is involved in plant growth and development, including leaf starch degradation, senescence, anthers development, regulation of lipid metabolism, and maintenance of peroxisome mass. More and more studies have shown that autophagy plays a role in stress response and contributes to maintain plant survival. The meristem is the basis for the formation and development of new tissues and organs during the post-embryonic development of plants. The differentiation process of meristems is an extremely complex process, involving a large number of morphological and structural changes, environmental factors, endogenous hormones, and molecular regulatory mechanisms. Recent studies have demonstrated that autophagy relates to meristem development, affecting plant growth and development under stress conditions, especially in shoot and root apical meristem. Here, we provide an overview of the current knowledge about how autophagy regulates different meristems under different stress conditions and possibly provide new insights for future research. [ABSTRACT FROM AUTHOR]

SUMMARY: Inorganic phosphate (Pi) is essential for plant growth. However, Pi is often limiting in soil. Hence, plants have established several mechanisms of response to Pi starvation. One of the important mechanisms is Pi recycling, which includes membrane lipid remodeling and plastid DNA degradation via catabolic enzymes. However, the involvement of other degradation systems in Pi recycling remains unclear. Autophagy, a system for degradation of intracellular components, contributes to recycling of some nutrients, such as nitrogen, carbon, and zinc, under starvation. In the present study, we found that autophagy‐deficient mutants depleted Pi early and exhibited severe leaf growth defects under Pi starvation. The main cargo of autophagy induced by early Pi depleted conditions was the endoplasmic reticulum (ER), indicating that ER‐phagy, a type of autophagy that selectively degrades the ER, is involved in the response to the early phase of Pi starvation for contribution to Pi recycling. This ER‐phagy was suppressed in an INOSITOL‐REQUIRING ENZYME 1 double mutant, ire1a ire1b, in which ER stress responses are defective, suggesting that the early Pi starvation induced ER‐phagy is induced by ER stress. Furthermore, iron limitation and inhibition of lipid‐reactive oxygen species accumulation suppressed the ER‐phagy. Interestingly, membrane lipid remodeling, a response to late Pi starvation, was accelerated in the ire1a ire1b under early Pi‐depleted conditions. Our findings reveal the existence of two different phases of responses to Pi starvation (i.e. early and late) and indicate that ER stress‐mediated ER‐phagy is involved in Pi recycling in the early phase to suppress acceleration of the late phase. Significance Statement: Autophagy is induced by phosphate (Pi)‐starvation, although whether it is involved in Pi‐recycling remains unclear. We discovered that, at the early phase of Pi‐starvation, autophagy induced by iron‐mediated endoplasmic reticulum (ER)‐stress selectively degrades the ER to contribute to Pi‐recycling. This mechanism suppressed a response to late Pi‐starvation, membrane lipid remodeling. Our results reveal the mechanistic importance of autophagy in the response to Pi‐starvation and show that the plant response to Pi‐starvation has two distinct phases: early and late. [ABSTRACT FROM AUTHOR]