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Drought had affected the crops production in Morocco, during the last decade. Plants breeding is still a solution to increase crops tolerance for water scarcity. Using natural biofertilizer based on microorganisms still a good practice to enhance the resilience of agriculture to drought. The objective of this study is to investigate the effect of water shortage and use of a biofertilizer based on the strain of Pseudomonas putida on five genotypes of eggplants selected for drought tolerance under the semi-arid of the northeast of Morocco. Two irrigations regimes: 100% (amount of water irrigation made by growers) and 50% of this amount with and without the biofertilizer (1 × 108 UFC/g). The biofertilizer was applied three times during the plant growth stages. The experiment was conducted at commercial farm production and using a randomized complete block design. Plants were organized in blocks containing 3 plants for each genotype and repeated in 5 repetitions. Crops were planted on August 3rd, 2022, and experiments ended on January 2nd, 2023. The results showed different responses among the genotypes in terms of growth. The effect of Pseudomonas on plant height showed that there was a significant increase, at 100% irrigation for C14, B3, C8, B5 and C11 with 20%, 19%, 17%, 14.29% and 12,5%, respectively compared with the control. For C8 and B3, when subjected to 100% water with biofertilizer, there was an increase in the average number of fruits compared to 100% water without the biofertilizer. The highest yield was recorded with B5 under 100% irrigation + fertilizer (1.35 kg/plant). Water shortage impacted the productivity of all genotypes and the fruit number and yield increased with the use of the biofertilizer. Our study is still valuable under the conditions of this trial and more experiments will be needed at several seasons and at different growing conditions. [ABSTRACT FROM AUTHOR]

Serotonin is a well-known animal hormone and ubiquitous monoamine. In recent years, its presence in plants has attracted the attention of many researchers. In plants, serotonin as signaling hormone plays a pivotal role in hormonal crosstalk, regulating antioxidant metabolism and developmental processes under abiotic stresses. Among abiotic stresses, salt stress considerably influences Guizotia abyssinica growth and physio-chemical functions. The effect of exogenous serotonin was assessed to ameliorate the harmful effect of salinity stress at different levels. All the growth parameters, chlorophyll pigments, gas exchange indicators, and nitrate reductase activity were decreased under all salinity levels while 2-thiobarbituric acid reactive substances (TBARS), proline, and antioxidant activities were increased. Serotonin improved the length of roots and shoots, basal diameter, leaf number, area, width and length, root dry matter, stem dry matter, leaves dry matter, chlorophyll a, chlorophyll b, chlorophyll fluorescence, transpiration rate, stomatal conductance, photosynthetic rate, relative water content, water use efficiency, and nitrate reductase under salt stress condition. Moreover, the upregulation of antioxidant enzymes evoked by the salt stress was further enhanced. Taken together, salt stress inhibited the growth and performance of G. abyssinica, however, exogenous application of serotonin fortified its tolerance by mitigating membrane damage and improving assimilatory functions, plant water status and plant defense metabolism, thereby lowering the adverse effects of salt stress on various plant growth performance and physio-biochemical functions. [ABSTRACT FROM AUTHOR]

Introduction: Water limitation is one of the most important abiotic factors that can limit plant growth and yield due to production of reactive oxygen species (ROS) like H2O2 and the reduction of chlorophyll content. To protect against oxidative stress, plant cells produce both antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX), and non-enzymatic antioxidants such as low weight molecules like proline, sugars and ascorbate. Also water limitation disturbs the mineral-nutrient relations in plants through their effects on nutrient availability and numerous of physiological and biochemical destruction in the vegetative and reproductive periods of plant development. Several strategies have been suggested in order to improve yield under abiotic and biotic stresses in plants, among them application of Plant Growth Promoting Rhizobacteria (PGPR) and nano particles such as nano iron-silicon oxide play a key role in yield improvement. A better understanding of physiological responses under water limitation may help in programs which the objective is to improve the drouht resistance of crop. During the course of these stresses, active solute accumulation of compatible solutes such as proline and the activities CAT, POD and PPO enzymes are claimed to be an effective stress tolerance mechanism. Therefore, the aim of this study was to evaluate the effects of bio-fertilizers and nano iron oxide and nano oxide on some physiological and biochemical (i.e., antioxidant enzyme activity, chlorophyll, protein, soluble sugars and proline) responses of triticale under water limitation conditions. Materials and methods: An experiment was conducted as factorial based on randomized complete block design with three replicates at the research farm of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2021. The experimental factors were included of irrigation in three levels (full irrigation as control, irrigation withholding at 50% of booting and heading stages as severe and moderate water limitation respectively (BBCH 43 and 55 respectively), application of bio fertilizers in four levels (no application as control, application of Azospirilum, Pseudomonas, both application Azospirilum and Pseudomonas) and nanoparticles foliar application at four levels (foliar application with water as control, nano iron oxide foliar application (1 g.l-1), nano silicon oxide (50 mg.l-1), both application nano iron-silicon oxide). Psedomunas and Azospirilum were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. For inoculation seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1x108 colony forming units (CFU). In each plot there were 5 rows with 2 m long. In each experimental plot, two marginal rows and 0.5 m from beginning and ending of planting lines were removed data were measured from the middle lines. The used nano silicon-iron oxide had the average particle size less than 30 nm and special surface of particles was more than 30 m2.g-1. They were product of Nanomaterial US Research which was provided by Pishgaman Nanomaterials Company of Iran. Nano iron oxide and nano silicon powder added to deionized water and was placed on ultra sonic equipment (100 W and 40 kHz) on a shaker for better solution. Foliar application of nano silicon oxide and putrecine were done in two stages of period growth BBCH 21 and 30. Results and discussion: The results showed that total chlorophyll content (48.16%), quantum yield (36.05%), relative water content (35.83%) and grain yield (43.28%) increased in dual application of bio fertilizers and nano particles foliar application under full irrigation conditions compared to no application of bio fertilizers and nano particles under irrigation cut off at booting stage. But under such conditions, electrical conductivity, hydrogen peroxide and malondialdehyde content decreased 35.67, 53.16 and 56.32% respectively compared to no application of PGPR and nanoparticles under irrigation withholding in booting stage. Also, the application of PGPR and nanoparticles under irrigation cut off in booting stage increased the activity of catalase, peroxidase and polyphenol oxidase enzymes (47.06, 55.69 and 36.53% respectively), proline and soluble sugars content (45.41 and 46.93% respectively) compared to no application of PGPR and nanoparticles under full irrigation conditions. Conclusion: Based on the results of this study, the application of plant growth promoting rhizobacteria and nonoparticle can increase grain yield of triticale under water limitation conditions due to improving biochemical and physiological traits. [ABSTRACT FROM AUTHOR]

AbstractWater deficit stress (WDS) is one of the most significant abiotic limiting factors in cultivated crops, including cotton (Gossypium barbadense L.). With global climate change and the destruction of ecological balance, the frequency and severity of drought events are increasing in many regions around the world. Therefore, the aim of the present work was to investigate the potential of using nano zinc particles (ZnO-NPs), plant growth-promoting rhizobacteria (Azospirillum sp.), and their combination to mitigate the negative impacts of WDS on cotton var. Giza 96. Extended irrigation intervals of 30 and 45 days led to considerable decreases in plant height, chlorophyll content, relative water content (RWC), yield, and cotton fiber quality compared to the optimal irrigation interval (every 15 days). When applied individually or in combination, ZnO-NPs and Azospirillum sp. can ameliorate the negative effects of WDS on cotton growth and productivity. Overall, the use of Azospirillum sp. and ZnO-NPs, either individually or in combination, has demonstrated their potential to enhance cotton growth and yield parameters (plant height, dry weight, leaf area, chlorophyll pigment, seed index, seed yield, and lint%) under prolonged irrigation intervals during 2021 and 2022 seasons. Antioxidant enzymes activity comprising catalase (CAT), peroxidase (POD), and polyphenol oxidase (PPO) and proline content were increased under drought stress. Cotton fiber quality parameters including length, strength, and micronaire were insignificantly affected under low irrigation rate. The combination of ZnO-NPs and Azospirillum sp. provided the most effective mitigation of WDS during both experimental seasons, outperforming the effects of individual applications. [ABSTRACT FROM AUTHOR]

Background: Heat stress is one of the abiotic stresses that make wheat crops vulnerable, which significantly impacts crop production around the world. An increase in temperature during the reproductive phase (anthesis) beyond the optimal range of 15–20 °C leads to decreased crop production, poor quality of the grain, and altered physiological and biochemical processes. To study the association between high temperature and physio-biochemical traits under normal and late sown, a set of fifteen genotypes was utilized. Results: Relative water content under high temperatures had an overall decrease of 8.7%. However, grain protein and malondialdehyde content were higher in the stressed conditions than in the control, with increases of 20.2% and 38.9%, respectively. Marker Xgwm67, located on chromosome 5B, was found to be significantly associated with malondialdehyde content (R2 = 21%) and Xgwm570, located on 6A, was closely linked to relative water content as well as grain protein content (R2 = 16%) revealed by regression analysis. The correlation matrix displays a positive association between the control and stressed condition by R2 = 0.92, 0.82, and 0.53 in malondialdehyde, relative water content, and grain protein, respectively. However, there was a negative correlation between water content–malondialdehyde and malondialdehyde–grain protein, though there was only a 4% correlation between grain protein content (control) and relative water content (stressed). Based on the tolerance matrix, WH730 and RAJ4079 were heat tolerant, and DBW173 and HD3086 were sensitive. Conclusions: These findings indicate that to identify tolerant genotypes, physiological and biochemical traits can be utilized as an alternate criterion, and these closely associated markers can be applied for improved late-planted wheat production through MAS. The breeding scheme and genome editing by recognizing novel genes through physio-biochemical parameters, marker-assisted selection, and prospective screening of tolerant genotypes are proclaimed by the study. [ABSTRACT FROM AUTHOR]

Glucan phosphorylase is present in plants in two isozymes, namely, a plastidial isoform (PHO1) and a cytosolic isoform (PHO2), and is involved in starch-related carbohydrate metabolism. The aim of this study was to determine whether mutations in the genes encoding glucan phosphorylase caused these plants to have increased resistance to short-term drought. One of the strategies plants use to defend themselves against drought stress is to change their starch content, which may be due to changes in glucan phosphorylase activity. In our greenhouse pot experiment, we used potato leaves from wild-type plants and transgenic mutant lines with reduced expression of genes encoding both PHO isozymes. The plants were exposed to drought or were grown under optimal conditions. A lack of water strongly affected the water saturation deficit (WSD) and leaf protein content. The activity of the plastidial glucan phosphorylase isoform (PHO1) in mutant plants increased under drought stress, in contrast to its activity in wild-type plants. After analyzing several physiological parameters, we found that suppressed expression of the gene encoding one of the subunits of plastidial glucan phosphorylase, PHO1a, resulted in increased tolerance to drought in potatoes. [ABSTRACT FROM AUTHOR]

Drought had affected the crops production in Morocco, during the last decade. Plants breeding is still a solution to increase crops tolerance for water scarcity. Using natural biofertilizer based on microorganisms still a good practice to enhance the resilience of agriculture to drought. The objective of this study is to investigate the effect of water shortage and use of a biofertilizer based on the strain of Pseudomonas putida on five genotypes of eggplants selected for drought tolerance under the semi-arid of the northeast of Morocco. Two irrigations regimes: 100% (amount of water irrigation made by growers) and 50% of this amount with and without the biofertilizer (1x108 UFC/g). The biofertilizer was applied three times during the plant growth stages. The experiment was conducted at commercial farm production and using a randomized complete block design. Plants were organized in blocks containing 3 plants for each genotype and repeated in 5 repetitions. Crops were planted on August 3rd, 2022, and experiments ended on January 2d, 2023. The results showed different responses among the genotypes in terms of growth. The effect of Pseudomonas on plant height showed that there was a significant increase, at 100% irrigation for C14, B3, C8, B5 and C11 with 20%, 19%, 17%, 14,29% and 12,5%, respectively compared with the control. For C8 and B3, when subjected to 100% water with biofertilizer, there was an increase in the average number of fruits compared to 100% water without the biofertilizer. The highest yield was recorded with B5 under 100% irrigation + fertilizer (1,35 kg/plant). Water shortage impacted the productivity of all genotypes and the fruit number and yield increased with the use of the biofertilizer. Our study is still valuable under the conditions of this trial and more experiments will be needed at several seasons and at different growing conditions.

Abstract Background Heat stress is one of the abiotic stresses that make wheat crops vulnerable, which significantly impacts crop production around the world. An increase in temperature during the reproductive phase (anthesis) beyond the optimal range of 15–20 °C leads to decreased crop production, poor quality of the grain, and altered physiological and biochemical processes. To study the association between high temperature and physio-biochemical traits under normal and late sown, a set of fifteen genotypes was utilized. Results Relative water content under high temperatures had an overall decrease of 8.7%. However, grain protein and malondialdehyde content were higher in the stressed conditions than in the control, with increases of 20.2% and 38.9%, respectively. Marker Xgwm67, located on chromosome 5B, was found to be significantly associated with malondialdehyde content (R 2 = 21%) and Xgwm570, located on 6A, was closely linked to relative water content as well as grain protein content (R 2 = 16%) revealed by regression analysis. The correlation matrix displays a positive association between the control and stressed condition by R 2 = 0.92, 0.82, and 0.53 in malondialdehyde, relative water content, and grain protein, respectively. However, there was a negative correlation between water content–malondialdehyde and malondialdehyde–grain protein, though there was only a 4% correlation between grain protein content (control) and relative water content (stressed). Based on the tolerance matrix, WH730 and RAJ4079 were heat tolerant, and DBW173 and HD3086 were sensitive. Conclusions These findings indicate that to identify tolerant genotypes, physiological and biochemical traits can be utilized as an alternate criterion, and these closely associated markers can be applied for improved late-planted wheat production through MAS. The breeding scheme and genome editing by recognizing novel genes through physio-biochemical parameters, marker-assisted selection, and prospective screening of tolerant genotypes are proclaimed by the study.

IntroductionWater limitation is one of the most important abiotic factors that can limit plant growth and yield due to production of reactive oxygen species (ROS) like H2O2 and the reduction of chlorophyll content. To protect against oxidative stress, plant cells produce both antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX), and non-enzymatic antioxidants such as low weight molecules like proline, sugars and ascorbate. Also water limitation disturbs the mineral-nutrient relations in plants through their effects on nutrient availability and numerous of physiological and biochemical destruction in the vegetative and reproductive periods of plant development. Several strategies have been suggested in order to improve yield under abiotic and biotic stresses in plants, among them application of Plant Growth Promoting Rhizobacteria (PGPR) and nano particles such as nano iron-silicon oxide play a key role in yield improvement. A better understanding of physiological responses under water limitation may help in programs which the objective is to improve the drouht resistance of crop. During the course of these stresses, active solute accumulation of compatible solutes such as proline and the activities CAT, POD and PPO enzymes are claimed to be an effective stress tolerance mechanism. Therefore, the aim of this study was to evaluate the effects of bio-fertilizers and nano iron oxide and nano oxide on some physiological and biochemical (i.e., antioxidant enzyme activity, chlorophyll, protein, soluble sugars and proline) responses of triticale under water limitation conditions.Materials and methodsAn experiment was conducted as factorial based on randomized complete block design with three replicates at the research farm of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2021. The experimental factors were included of irrigation in three levels (full irrigation as control, irrigation withholding at 50% of booting and heading stages as severe and moderate water limitation respectively (BBCH 43 and 55 respectively), application of bio fertilizers in four levels (no application as control, application of Azospirilum, Pseudomonas, both application Azospirilum and Pseudomonas) and nanoparticles foliar application at four levels (foliar application with water as control, nano iron oxide foliar application (1 g.L-1), nano silicon oxide (50 mg.L-1), both application nano iron-silicon oxide). Psedomunas and Azospirilum were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. For inoculation seeds were coated with gum Arabic as an adhesive and rolled into the suspension of bacteria until uniformly coated. The strains and cell densities of microorganisms used as PGPR in this experiment were 1×108 colony forming units (CFU). In each plot there were 5 rows with 2 m long. In each experimental plot, two marginal rows and 0.5 m from beginning and ending of planting lines were removed data were measured from the middle lines. The used nano silicon-iron oxide had the average particle size less than 30 nm and special surface of particles was more than 30 m2.g-1. They were product of Nanomaterial US Research which was provided by Pishgaman Nanomaterials Company of Iran. Nano iron oxide and nano silicon powder added to deionized water and was placed on ultra sonic equipment (100 W and 40 kHz) on a shaker for better solution. Foliar application of nano silicon oxide and putrecine were done in two stages of period growth BBCH 21 and 30.Results and discussionThe results showed that total chlorophyll content (48.16%), quantum yield (36.05%), relative water content (35.83%) and grain yield (43.28%) increased in dual application of bio fertilizers and nano particles foliar application under full irrigation conditions compared to no application of bio fertilizers and nano particles under irrigation cut off at booting stage. But under such conditions, electrical conductivity, hydrogen peroxide and malondialdehyde content decreased 35.67, 53.16 and 56.32% respectively compared to no application of PGPR and nanoparticles under irrigation withholding in booting stage. Also, the application of PGPR and nanoparticles under irrigation cut off in booting stage increased the activity of catalase, peroxidase and polyphenol oxidase enzymes (47.06, 55.69 and 36.53% respectively), proline and soluble sugars content (45.41 and 46.93% respectively) compared to no application of PGPR and nanoparticles under full irrigation conditions.ConclusionBased on the results of this study, the application of plant growth promoting rhizobacteria and nonoparticle can increase grain yield of triticale under water limitation conditions due to improving biochemical and physiological traits.

Abstract A two-year field trial was set up to investigate the effects of applying 3 tons ha-1 of wheat (3WB) and cotton biochar (3CB) alone or in combination with chemical nitrogen (N) and phosphorus (P) fertilizers on biochemical properties, yield and nutrient content of safflower under normal irrigation and water stress (irrigation cut-off at flowering stage) conditions. The total water applied in the chemical treatments [150 kg ha−1 N + 50 kg ha−1 P (100% of the recommended dose) and 112.5N + 37.5P (75% of the recommended dose)] under water stress, was significantly higher than other treatments. Application of 112.5N + 37.5P + 3CB increased RWC from 57.5 to 59.4% and the total chlorophyll content from 80.7 to 128.1%, compared to the control. The carotenoid content, catalase and peroxidase in 112.5N + 37.5P + 3CB were lower than chemical fertilizers. Under water stress, the seed yield of 112.5N + 37.5P + 3CB was 10.2–12.6% higher than 112.5N + 37.5P + 3WB. The higher chlorophyll content, RWC, remobilization efficiency and nutrient content in 112.5N + 37.5P + 3CB compared to other treatments was associated with seed yield enhancement. The findings indicate that the combination of CB with 75% recommended dosage of N and P, may be the optimal approach for enhancing safflower production under water stress conditions.

Abstract Rice is a staple food in the diets of more than half of the world's population. With India's irregular rainfall patterns and continual environmental anomalies, particularly in Kerala, the identification of climate-smart management practices which can withstand drought is critical. In this context, atrial was conducted in the experimental plots to evolve effective water and nutrient management practices under aerobic rice in lateritic soils of Kerala. However, during the experiment in a few treatments, rolling of leaves was observed, and when explored for the reasons, it was due to soil moisture deficit and plant water stress. When compared to other crop species, rice is highly vulnerable to water deficit. In this regard, an attempt has been made to study the leaf rolling pattern in aerobic rice and how this can be managed with a few soil amendments so that rice productivity can be sustained. The results showed that plant growth parameters, relative water content (RWC), membrane leakage (ML) and spectral signatures were significantly affected by the leaf rolling. It was found that leaf rolling affected plants have less RWC and higher ML and are under drought stress. Pearson correlation analysis showed a strong positive correlation (P

Purpose: The study aimed to explore the effects of biofertilizer inoculation on the growth and morphophysiological traits of Red Angel and Wonderful pomegranate cultivars under salinity stress. Research method: The experiment utilized a factorial design based on a completely randomized design with four replications to assess the effects of salinity stress at three levels (control, 4, and 8 dS/m) and biofertilizer at four levels (control, Pseudomonas fluorescens, Glomus mosseae, and P. fluorescens + G. mosseae) on pomegranate plantlets. Findings: The results showed that the highest percentage of symbiosis was observed in P. fluorescens + G. mosseae, with 89.16% and 90.55% in the Red Angel and Wonderful cultivars, respectively. Salinity did not have any influence on the percentage of symbiosis in both cultivars. Furthermore, the application of biofertilizers increased the stem diameter, number of lateral branches, total number of leaves, leaf fresh and dry weight, root diameter, number of lateral roots, and relative water content of leaves in both cultivars. Additionally, all biofertilizers reduced cell membrane injury at all salinity levels by approximately 40%. Salinity decreased the leaf fresh and dry weight, root fresh and dry weight, and number of lateral roots, while increasing cell membrane injury in both cultivars. Research limitations: No limitations were identified. Originality/Value: The results highlight the potential of biofertilizers in mitigating the adverse effects of salinity stress on pomegranates, particularly when P. fluorescens and G. mosseae are combined.

Water scarcity is the major limiting factor for growth and yield in arid and semi-arid regions. Therefore, an experiment was conducted to investigate the effect of deficit irrigation on the yield, fruit quality and physiological responses of cucumber plants Cucumis sativus (L.) Kish F1 (i.e., a scion) either grafted or not grafted on the African horned cucumber rootstock under open field conditions. Irrigation treatments were 100, 80, and 60% of crop evapotranspiration (ETc). Results showed that plant growth and yield significantly decreased in response to deficit irrigation in both grafted and non-grafted plants. The fruit number and yield of grafted onto African horned cucumber rootstock were higher than those of non-grafted plants under deficit irrigation (60% ETc). Fruit firmness and vitamin C content significantly decreased with increasing water-deficit stress, while total soluble solid, phenolic compounds and antioxidant activity increased. Fruits of grafted plants had a significantly higher quality compared with non-grafted fruits under all irrigation regimes. Likewise, grafted plants showed significantly higher proline and leaf relative water content and lower electrolyte leakage compared with non-grafted plants under all irrigation regimes. These findings suggest that grafting cucumber onto drought-tolerant African horned cucumber rootstock could improve water-stress tolerance in cucumber. [ABSTRACT FROM AUTHOR]

Background and Objectives: Perennial sow-thistle (Sonchus arvensis L.) is a medicinal plant belong to the sunflower family with anti-diabetic, antidepressant and anti-cancer properties. The crisis of salinization of agricultural lands is considered as one of the most important problems of the world and Iran, and as an environmental stress, it has a direct effect on many plant characteristics under stress. Since there is little information about the response of Sonchus plant to salinity stress, the present experiment was conducted to investigate the effect of salinity on some morphological and physiological traits as well as the activity of antioxidant enzymes under salinity conditions. Materials and Methods: The experiment was conducted as a completely randomized design with three repetitions in 2018 in the greenhouse of the Faculty of Agriculture of Urmia University. Salinity stress was applied at four levels (0, 50, 100 and 150 mM of NaCl salt) at the 6-8 leaf stage, and shoot dry weight, root dry weight and root length were recorded. Also, photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids), protein content, relative leaf water content (RWC), proline and carbohydrate contents, antioxidant capacity (DPPH and FRAP) and the activity of antioxidant enzymes including catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD), peroxidase (PX) were measured in the lower and middle leaves of the plants. Analysis of variance (ANOVA) for the obtained data and comparison of the means of the treatments using Duncan’s test were implemented in SAS 9.4 software. Results: The results showed that root length, root dry weight and shoot dry weight decrease significantly with increasing salinity level. Also, the content of chlorophyll a and b increased in salinity conditions, while salinity decreased the amounts of carotenoids. The highest amount of chlorophyll was observed in the lower leaf under 150 mM NaCl. The content of protein, proline and soluble sugar was enhanced with increasing salinity level; the maximum amount of these parameters was observed in the middle leaf at 150 mM NaCl. The highest amount of total phenolic and flavonoid compounds was observed at the stress level of 50 mM NaCl. The content of sodium ion (Na+) increased with increasing salinity level, while the amount of potassium ion (K+) declined. The activity of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase enzymes, as well as FRAP and DPPH antioxidant capacity increased in salinity conditions. Conclusion: According to the obtained results, it can be concluded that Sonchus arvensis plant copes with salinity through increasing some osmolytes under stress conditions. Moreover, an enhancement of the amount of chlorophyll a and b at high levels of salinity showed that Sonchus arvensis is probably a salt-tolerant plant. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of pinching and foliar spraying of thidiazuron on improving the tolerance to water-deficit stress in Pelargonium graveolens plants, a factorial experiment was conducted in the form of a completely randomized design with four replications in the research greenhouses of the Faculty of Agriculture of Lorestan University in 2022. The first factor was water deficit stress (80 (control), 50 and 20% available water in the soil (AWC)), the second factor was pinching and non-pinching, and the third one included thidiazoron foliar spraying (zero, 5 and 10 mg/liter). The results showed that water deficit stress had a decrease effect on the indices of plant height, number of lateral branches, total fresh and dry weight, relative water content and essential oil percentage, whereas it had an increase impact on electrolyte leakage, malondialdehyde content and catalase enzyme activity. Pinching of plants and foliar application of thidiazuron in the control level decreased the plant height, number of leaves and the relative water content of the leaves, but increased total fresh and dry weight, root growth, concentration of photosynthetic pigments and electrolyte leakage. However, under the water deficit stress, plant height, number of lateral branches, number of leaves, root growth, total fresh and dry weight, relative leaf water content and essential oil yield increased and electrolyte leakage, malondialdehyde content and catalase enzyme activity decreased. In general, the results showed that the application of pinching and thidiazoron, particularly at a concentration of 5 mg/liter, resulted in a reduction of the adverse effects of water deficit stress by improving the water balance and promoting root growth. [ABSTRACT FROM AUTHOR]

SUMMARY: Polyamines are involved in several plant physiological processes. In Arabidopsis thaliana, five FAD‐dependent polyamine oxidases (AtPAO1 to AtPAO5) contribute to polyamine homeostasis. AtPAO5 catalyzes the back‐conversion of thermospermine (T‐Spm) to spermidine and plays a role in plant development, xylem differentiation, and abiotic stress tolerance. In the present study, to verify whether T‐Spm metabolism can be exploited as a new route to improve stress tolerance in crops and to investigate the underlying mechanisms, tomato (Solanum lycopersicum) AtPAO5 homologs were identified (SlPAO2, SlPAO3, and SlPAO4) and CRISPR/Cas9‐mediated loss‐of‐function slpao3 mutants were obtained. Morphological, molecular, and physiological analyses showed that slpao3 mutants display increased T‐Spm levels and exhibit changes in growth parameters, number and size of xylem elements, and expression levels of auxin‐ and gibberellin‐related genes compared to wild‐type plants. The slpao3 mutants are also characterized by improved tolerance to drought stress, which can be attributed to a diminished xylem hydraulic conductivity that limits water loss, as well as to a reduced vulnerability to embolism. Altogether, this study evidences conservation, though with some significant variations, of the T‐Spm‐mediated regulatory mechanisms controlling plant growth and differentiation across different plant species and highlights the T‐Spm role in improving stress tolerance while not constraining growth. [ABSTRACT FROM AUTHOR]

Developing new bread wheat varieties that can be successfully grown in saline conditions has become a pressing task for plant breeders. High-throughput phenotyping tools are crucial for this task. Proximal remote sensing is gaining popularity in breeding programs as a quick, cost-effective, and non-invasive tool to assess canopy structure and physiological traits in large genetic pools. Limited research has been conducted on the effectiveness of combining RGB and thermal imaging to assess the salt tolerance of different wheat genotypes. This study aimed to evaluate the effectiveness of combining several indices derived from thermal infrared and RGB images with artificial neural networks (ANNs) for assessing relative water content (RWC), chlorophyll a (Chla), chlorophyll b (Chlb), total chlorophyll (Chlt), and plant dry weight (PDW) of 18 recombinant inbred lines (RILs) and their 3 parents irrigated with saline water (150 mM NaCl). The results showed significant differences in various traits and indices among the tested genotypes. The normalized relative canopy temperature (NRCT) index exhibited strong correlations with RWC, Chla, Chlb, Chlt, and PDW, with R2 values ranging from 0.50 to 0.73, 0.53 to 0.76, 0.68 to 0.84, 0.68 to 0.84, and 0.52 to 0.76, respectively. Additionally, there was a strong relationship between several RGB indices and measured traits, with the highest R2 values reaching up to 0.70. The visible atmospherically resistant index (VARI), a popular index derived from RGB imaging, showed significant correlations with NRCT, RWC, Chla, Chlb, Chlt, and PDW, with R2 values ranging from 0.49 to 0.62 across two seasons. The different ANNs models demonstrated high predictive accuracy for NRCT and other measured traits, with R2 values ranging from 0.62 to 0.90 in the training dataset and from 0.46 to 0.68 in the cross-validation dataset. Thus, our study shows that integrating high-throughput digital image tools with ANN models can efficiently and non-invasively assess the salt tolerance of a large number of wheat genotypes in breeding programs. [ABSTRACT FROM AUTHOR]

Tunisia is known as an underprivileged country in water resources, and water scarcity is evident in certain regions. In the long term, this situation could become more exacerbated, considering the increased risk of aridity. In this context, this work was carried out to study and compare the ecophysiological behavior of five olive cultivars facing drought stress and to evaluate the contribution of rhizobacteria to mitigate the effects of drought stress on these cultivars. The results showed a significant decrease in the relative water content (RWC) with the lowest percentage recorded for the 'Jarboui' cultivar (RWC = 37%), and the highest percentage was registered for the 'Chemcheli' cultivar (RWC = 71%). In addition, the performance index (PI) decreased for all the five cultivars and it reached the lowest values for 'Jarboui' and 'Chetoui' with 1.51 and 1.57, respectively. For the SPAD index, a decrease was registered for all the cultivars, except 'Chemcheli' (SPAD index = 89). Furthermore, the bacterial inoculation treatment improved the responses of cultivars to water stress. In fact, for all of the studied parameters, it was found that rhizobacterial inoculation significantly attenuated the effects of drought stress with variability dependent on the level of tolerance of the tested cultivars. This response improvement was noted especially in susceptible cultivars like 'Chetoui' and 'Jarboui'. [ABSTRACT FROM AUTHOR]

Rice production is severely threatened by drought stress. To develop drought-tolerant varieties, the selection of donors for the breeding programme is crucial. Twenty-one rice genotypes were evaluated at the vegetative and reproductive stages under drought. Higher relative water content (> 65%) and leaf water potential (> − 3.50 MPa) in Danteshwari, Mahamaya, Samleshwari, Poornima, IBD-1, Safri 17, Sahabhagidhan, Vandana and N22 explained their drought tolerance with higher biomass production, lower drought score and early stress recovery rate of 1 and 3 under vegetative stage drought. At the reproductive stage drought, higher grain yield and less relative yield reduction was found in Mahamaya (2.42 t/ha, 46.37%), Samleshwari (2.05 t/ha, 42.88%), Poornima (1.86 t/ha, 42.67%), Sahabhagidhan (2 t/ha, 57.72%) and Danteshwari (2 t/ha, 39.11%), showed higher tolerance due to greater leaf water potential and biomass with a lower reduction in grain filling percentage due to more remobilization of assimilates to the grains. Though, N22 and Anjali flowered 5–7 days earlier in drought stress compared to well-watered condition, partially responsible for increased grain filling under drought. Therefore, visual selection for a large sink size under favorable conditions and higher biomass accumulation under vegetative drought stress with greater fertility under reproduction stage is favorable for maintaining higher grain yield in rice. Further, higher expression of OsAP37, EDT1, OsLEA3-1, OsDIL, OsDRAP1, OsNAC14, OsNAR2.1, OsWRKY30 and OsRab7 in Mahamaya, Samleshwari, Poornima, Sahabhagidhan, and Danteshwari supported the higher grain yield under drought stress. [ABSTRACT FROM AUTHOR]

The present research was conducted to investigate some physiological traits of 22 bread wheat landraces as well as five registered cultivars under irrigated and late drought stress. In this study, significant differences were obtained between landraces in the investigated physiological traits generally and the responses of cultivars changed to years and applications. TGB 003232, TR 63581 and TGB 000534 landraces showed higher values than the average of registered cultivars in leaf relative water content under late drought stress conditions. According to rank analysis, Dağdaş 94, TGB 003232 and Müfitbey cultivars became prominent in drought tolerance at late developmental stages. In the photosystem II (PS II) maximum energy efficiency (Fv/Fm) value used to determine the drought tolerance of the genotypes, the bread wheat landrace Çalı basıran became prominent in all three stages. According to the results obtained, it is important to use landraces as a gene source in breeding studies in the physiological traits investigated. [ABSTRACT FROM AUTHOR]

Adaptability and significant economic value of the neem tree are well-known, as it can flourish in a variety of environmental conditions. While the neem seed production is highly sensitive to prevailing weather conditions during the reproductive phase and flowering behaviour of the tree. A study was conducted at Tamil Nadu Agricultural University, Coimbatore in 2023 with the primary objective of validating the weather influence on neem seed production using the logics of physiological responses, as a continuation of research conducted the previous year (2022). During the pre-flowering and flowering stages, diverse weather conditions led to notable changes in the physiological traits of neem trees, which displayed varying patterns of flowering. Trees that flowered consistently showed elevated levels of indole acetic acid (IAA) oxidase, relative water content, and nitrate reductase compared to those that lacked flowers or produced intermittently. In the flowering stage, the neem trees responded positively in terms of physiological aspects like IAA oxidase, relative water content, nitrate reductase, and exhibited lower proline levels, which can be attributed to the optimal maximum temperature, rainfall, and soil moisture. Proline levels rose during the pre-flowering stage due to soil moisture deficits but fell during the flowering stage with the onset of rain. These physiological changes, driven by climatic factors, are likely to enhance the flowering, fruiting, and overall yield of neem trees. [ABSTRACT FROM AUTHOR]

Purpose: The study aimed to explore the effects of biofertilizer inoculation on the growth and morphophysiological traits of Red Angel and Wonderful pomegranate cultivars under salinity stress. Research method: The experiment utilized a factorial design based on a completely randomized design with four replications to assess the effects of salinity stress at three levels (control, 4, and 8 dS/m) and biofertilizer at four levels (control, Pseudomonas fluorescens, Glomus mosseae, and P. fluorescens + G. mosseae) on pomegranate plantlets. Findings: The results showed that the highest percentage of symbiosis was observed in P. fluorescens + G. mosseae, with 89.16% and 90.55% in the Red Angel and Wonderful cultivars, respectively. Salinity did not have any influence on the percentage of symbiosis in both cultivars. Furthermore, the application of biofertilizers increased the stem diameter, number of lateral branches, total number of leaves, leaf fresh and dry weight, root diameter, number of lateral roots, and relative water content of leaves in both cultivars. Additionally, all biofertilizers reduced cell membrane injury at all salinity levels by approximately 40%. Salinity decreased the leaf fresh and dry weight, root fresh and dry weight, and number of lateral roots, while increasing cell membrane injury in both cultivars. Research limitations: No limitations were identified. Originality/Value: The results highlight the potential of biofertilizers in mitigating the adverse effects of salinity stress on pomegranates, particularly when P. fluorescens and G. mosseae are combined. [ABSTRACT FROM AUTHOR]

Soil pollution with heavy metals is a threat to crop production. Practically, application of silicon (Si) with biochar can be a cost-effective approach to immobilize metals in contaminated soils. Investigation of the anatomical and biochemical changes of corn leaf is important for describing the mechanisms of Si and biochar soil application in alleviating the negative effects of nickel (Ni) toxicity. A factorial pot experiment was conducted to investigate the effect of Si (0, 250 and 500 mg Si kg−1 soil) in combination with rice husk biochar (RHB) or sheep manure biochar (SMB) prepared at two pyrolysis temperatures (300 and 500 °C) on anatomical and biochemical properties of corn leaves in a Ni-polluted soil. The length, width, area and weight of third-leaf, and metaxylem and protoxylem of midrib improved by application of Si250 with RHB more than SMB. At Si250, RHB300 and RHB500 improved the stomatal area by 31.7 and 27.7 % compared to control (without biochar), respectively. The leaf membrane stability index was increased by increasing Si application level and reached 69 % in RHB300. In contrast to total chlorophyll, the highest carotenoid content, catalase and peroxidase was obtained by control (without Si and biochar) followed by SMB. At Si250, the highest relative water content (RWC) was observed in RHB300 by 34.8 % increase. Also, RHB300 had the highest total dry matter, with increases of 82.2, 120.0 and 83.1 % at Si0, Si250 and Si500, respectively. By increasing the Si level and biochar application, the shoot Ni decreased between 42.1 and 133.3 %. Combined application of Si250 with RHB300 resulted in the highest dry matter through improving the leaf dimensions, metaxylem and protoxylem areas of midrib, membrane stability index, total chlorophyll, and RWC, while Ni uptake was reduced.

In arid regions, one of the practical solutions to overcome the water shortage and increasing soil fertility is application of salicylic acid (SA) with biochar. A pot experiment was conducted to consider the combination of SA with biochar on biochemical and physiological parameters of triticale as a factorial experiment using a completely randomized design (RCD) with four replicates. Treatments consisted of irrigation regime (normal irrigation and irrigation according to 50 % field capacity), salicylic acid application [without SA (SA0) and 3 mM SA (SA3)] and fertilizer type including without fertilizer (control), application of 50 kg ha−1 phosphorus (P), and application of wheat biochar (WB), cotton biochar (CB) and sesame biochar (SB) (2 % w/w). Under water stress, CB at SA0 and SA3 could improve the total chlorophyll by 119.4 and 70.6 %, compared to control, respectively. Also, carotenoid content in SA3 treatments increased in the range of 75.8 to 34.6 % compared to SA0. CB at SA3, increased catalase activity by 11.4 % compared to SB. At SA3, the highest RWC was observed in WB and CB by 26.7 and 18.1 % increases compared to SA0, respectively. At SA3, CB could enhance grain yield by 24.8 % under water stress. Under water stress, at SA3, remobilization efficiency from 63.2 % in control was enhanced to 69.2, 74.3 and 68.1 % in WB, CB and SB, respectively. CB and WB had better chemical properties in terms of EC, N, P, K and micronutrients compared to SB. These properties of BC and WB enhanced their ability to increase the nutrient availability, biochemical properties and consequently the grain yield enhancement, especially when applied with SA3.

Many studies have demonstrated that brassinolide improves the drought tolerance of plants. This study aims to test whether the drought tolerance of chrysanthemums can be improved by brassinolide and to clarify the underlying physiological mechanism. An own-root chrysanthemum and a corresponding grafted-root line (Artemisia annua rootstock) were treated with brassinolide under three water levels in a randomised complete block design with five replications. The results showed that brassinolide increased the relative water content, net photosynthetic rate, chlorophyll (Chl) fluorescence parameters, Rubisco, ascorbate peroxidase, glutathione reductase, dehydroascorbate reductase and monodehydroascorbate reductase activities, ascorbate/dehydroascorbate, glutathione/oxidised glutathione and dry mass, and reduced the H2O2 content in the own-root and grafted-root chrysanthemums, especially under drought stresses. The magnitude of the changes to the parameters was greater in the own-root line than in the corresponding grafted-root line under brassinolide treatment. The above parameters showed significant differences (P < 0.05) between the brassinolide chrysanthemums and the corresponding non-brassinolide chrysanthemums under drought stresses. This might be the physiological mechanism of improved drought tolerance by brassinolide in chrysanthemums.

Chia (Salvia hispanica L.) cultivation in dry regions like Morocco requires understanding its drought tolerance for successful projects amidst climate change threats. In this context, a study was conducted to assess the effect of severe drought stress on chia seedlings. Under drought stress conditions, growth traits of the shoot part have been significantly decreased, while the root part did not change significantly compared to control conditions. A significant reduction in chlorophylls and carotenoids was noted in stressed chi seedlings. In comparison with control conditions, the predawn leaf water potential and stomatal conductance significantly decreased by about 81.4% and 35.3%, respectively, in stressed chia seedlings, without detecting any significant change in the relative water content. Drought-stressed chia seedlings exhibited significant accumulation of epicuticular wax (approximately 57.7%) on leaves compared to control seedlings. In addition, chia seedlings exhibited osmotic adjustment under conditions of severe drought stress, characterised by a substantial accumulation of proline (fourfold increase) and proteins (85.6%) compared to control conditions. Significant correlations have been established between some traits that interfere with plant responses to drought stress. Nonetheless, thorough examinations of chia's drought tolerance mechanisms are crucial for informed strategies for its cultivation in arid and marginal regions. [ABSTRACT FROM AUTHOR]

The knowledge about vulnerability of tree seedlings to severe droughts is important in order to select the most suitable species for forestry plantations in a context of extreme weather events induced by global climate change. We conducted a study aiming to evaluate the effects of lethal leaf dehydration on seedlings of nine tropical tree species cohabiting the same forest ecosystem, but differing in terms shade tolerance, maximum height, geographical distribution, and leaf mass per area. For this, the percentual loss of photochemical efficiency, measured as the loss of maximum quantum efficiency of photosystem II during leaf dehydration (PL[Fv/Fm]) was investigated. Statistically significant differences were found between species for the average values ​​of the relative water content (RWC) in which there is a loss of 10% and 50% of Fv/Fm. The species were separated in three groups: (a) species that showed the highest Fv/Fm losses at high RWC values, (b) intermediate species, and (c) species that showed significant Fv/Fm loss only at very low values of RWC. The PL[Fv/Fm] during leaf dehydration can be an useful methodology to select tree species for plantations in sites prone to severe droughts associated to extreme weather events. [ABSTRACT FROM AUTHOR]

The research was conducted at the National Institute of Agricultural Sciences located in Mayabeque province, Cuba, with the aim of determining the response of bean crops to controlled deficit irrigation applied at different stages of their biological cycle. The study was carried out during two planting seasons (January and October 2021) under semi-controlled conditions. Seeds of the Triunfo 70 cultivar were sown in concrete containers, and three irrigation suspension periods of 15 days were studied: during the vegetative growth stage (VG), flowering stage (FS), and grain filling stage (GFS), along with a control group irrigated at 100% of the ETc. After the irrigation suspensions, soil moisture, growth indicators, and yield components were evaluated. In VG during the second experiment, it reduced stem length, leaf number, and leaf area. Above-ground dry mass decreased in both experiments, as well as the mass of 100 grains and grams per plant. In FS, it reduced stem length, relative chlorophyll content (RCC), mass of 100 grains, and yield in grams per plant, while in GFS, only the RCC was affected. Based on the results, it can be concluded that the grain filling stage was the least sensitive to water deficiency, causing the least impact on yield. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, the cold resistance of five main nectarine (Prunus persica (L.) Batsch, var nectarine) cultivars grown in Shanxi Province of China was evaluated and compared. To explore the physio-biochemical mechanism underlying their cold resistance variations, semi-lethal low temperature (LT50) and thirteen cold resistance related parameters at six timepoints during overwintering were determined and analyzed. Results showed that these five nectarine cultivars could be classified into high cold resistant (HR), moderate cold resistant (MR) and low cold resistant (LR) groups. The HR cultivars were of higher relative water (RW) and proline (PRO) contents and superoxide dismutase (SOD) activity, but much lower relative electric conductivity (RE), malondialdehyde (MDA) content and catalase (CAT) activity. Moreover, the increase of PRO and abscisic acid (ABA) contents and decrease of RW content in HR cultivars were greater than other cultivars. Additionally, redundancy analysis (RDA) revealed that these indexes were significantly correlated with the HR cultivars, indicating that they could be used as potential markers for the cold resistance evaluation of nectarine germplasm resources. Cold stress occurs in late winter and early spring threatens greatly the nectarine industry. In this study, the semi-lethal low temperature (LT50) and thirteen cold resistance related parameters of five nectarine cultivars, including 'Nonglehong little princess' (LP), 'Luyou No. 5' (LY), 'Nonglehong No. 6' (NL), 'Zhongyou No. 20' (ZY) and 'Qiuhongzhu' (QH), were determined. Based on these parameters, they were categorized into high—(HR, including NL and LP), moderate—(MR, including QH) and low-cold resistant (LR, including ZY and LY) groups. The relative water (RW), proline (PRO), soluble sucrose (SS) and soluble protein (SP) contents, and superoxide dismutase (SOD) and peroxidase (POD) activities of HR cultivars were higher while their relative electronic conductivity (RE), malondialdehyde (MDA) and gibberellin acid (GA3) contents and catalase (CAT) activity were lower than other cultivars during natural overwintering. Redundancy analysis revealed that the lowest temperature in a day (LT) and LT50 significantly explains 69.8% and 10.9% of these physiological variables, respectively. Moreover, GA3 and indoleacetic acid (IAA) contents and CAT activity were positively correlated, while PRO, SS, ABA and RW contents were negatively correlated with both LT and LT50. Our study will be helpful in understanding the cold resistance variations of nectarine germplasm resources. [ABSTRACT FROM AUTHOR]

• Seed priming reduces the accumulation of proline, soluble sugars, and H 2 O 2 under irrigation regimes. • The adverse effects of drought stress regimes are alleviated by upregulating the activity of defense enzymes at seed priming. • The morphological and agronomic traits improve by seed priming. • The highest sesame seed yield produced in seed priming with salicylic acid. An experiment was set up as a split-plot factorial in a randomized complete block design with three replications to investigate the response of sesame genotypes to different seed priming methods under optimal water supply and drought stress conditions. The main factor was irrigation regime at three levels of irrigation after 45 % depletion of available soil water (control), irrigation after 65 % depletion of available soil water (moderate stress), and irrigation after 85 % depletion of available soil water (sever stress). The seed priming at five levels of none-priming (control), priming with pure water, priming with salicylic acid, priming with K 2 SO 4 , and priming with ZnSO 4 and genotype at three levels (Darab 14, Oltan, and Karaj) were factorially located in the sub plots. The results showed that the moderate and sever stress regimes boosted the H 2 O 2 level, proline and soluble sugars contents, anthocyanin amount, and activity of catalase, superoxide dismutase, peroxidase, and polyphenol oxidase while relative water content, leaf area index, number of capsules per plant, 1000-seed weight, biomass, seed yield, harvest index, and water use efficiency were reduced in such conditions. All seed priming treatments positively improved sesame development and growth under three irrigation regimes by enhancing the plant water content, upregulating the enzymatic and non-enzymatic defense system, and decreasing ROS production. The highest sesame seed yield was recorded in seed priming treatment with salicylic acid, averaging 1152.7 kg ha−1. The Karaj genotype produced the higher seed yield under control, moderate stress, and sever stress regimes (1765.7, 1271.0, and 771.4 kg ha−1, respectively). Overall, the results of the current study suggest that seed priming can be used as a practical solution to reduce the harmful effects of drought stress on the growth and yield of sesame genotypes. Finally, combination of the Karaj genotype × seed priming with salicylic acid is recommended to obtain the maximum sesame seed yield. [ABSTRACT FROM AUTHOR]

Cacao (Theobroma cacao L.) is noted to have a low tolerance to drought and is, therefore, not resilient to prolonged dry periods. The study sought to evaluate the morpho-anatomical and physiological responses of two clonal seedlings of cacao BR25 and K9 under drought stress and to explore the potential alleviating effects of salicylic acid (SA) at concentrations of 0.5 and 1.0 mM on the early vegetative stage. Eleven-month-old BR25 and K9 cacao were pre-treated with foliar application of 0.5 and 1.0-mM SA for 2 wk before the onset of drought conditions. Well-watered and drought seedlings with no pre-treatments served as the control. Water was withheld for 20 d, after which rewatering resumed for 3 mo. Results revealed that after 20 d of drought, both clonal varieties experienced a significant decline in relative water content (RWC) and increased ascorbate peroxidase (APX) and catalase activity. Changes in stem diameter were observed after a rewatering period of 3 mo. K9 exhibited a noticeable reduction in root and shoot dry weight and stomatal aperture after 20 d of drought, whereas BR25 showed a decrease in total chlorophyll content and chlorophylls a and b. Furthermore, the results of the study suggest that 0.5-mM SA has the potential to mitigate the drastic effects during drought in BR25 and K9 cacao by improving RWC, stomatal length, and width. On the other hand, 1.0-mM SA has the potential to alleviate the effects of drought experienced earlier on by improving root dry weight and APX activities of the seedlings. [ABSTRACT FROM AUTHOR]

Natural and synthetic phytohormones are widely used in agriculture. The synthetic cytokinin ethylenediurea (EDU) induces protection in plants against ozone phytotoxicity. In our study, new hybrid derivatives of EDU were synthesized and tested for phytoactivity. The germination potential (Gp), germination of seeds (G), and relative water content in leaves (RWC), characterizing the drought resistance of plants, were determined. The results of laboratory studies showed that EDU and its hybrid derivatives have a positive effect on root length, the growth and development of shoots, as well as the ability of plants to tolerate stress caused by a lack of water. [ABSTRACT FROM AUTHOR]

Maize production and productivity are affected by drought stress in tropical and subtropical ecologies, as the majority of the area under maize cultivation in these ecologies is rain-fed. The present investigation was conducted to study the physiological and biochemical effects of 24-Epibrassinolide (EBR) as a plant hormone on drought tolerance in maize. Two maize hybrids, Vivek hybrid 9 and Bio 9637, were grown under three different conditions: (i) irrigated, (ii) drought, and (iii) drought+EBR. A total of 2 weeks before the anthesis, irrigation was discontinued to produce a drought-like condition. In the drought+EBR treatment group, irrigation was also stopped, and in addition, EBR was applied as a foliar spray on the same day in the drought plots. It was observed that drought had a major influence on the photosynthesis rate, membrane stability index, leaf area index, relative water content, and leaf water potential; this effect was more pronounced in Bio 9637. Conversely, the activities of antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) increased in both hybrids under drought conditions. Specifically, Vivek hybrid 9 showed 74% higher CAT activity under drought conditions as compared to the control. Additionally, EBR application further enhanced the activity of this enzyme by 23% compared to plants under drought conditions. Both hybrids experienced a significant reduction in plant girth due to drought stress. However, it was found that exogenously applying EBR reduced the detrimental effects of drought stress on the plant, and this effect was more pronounced in Bio 9637. In fact, Bio 9637 treated with EBR showed an 86% increase in proline content and a 70% increase in glycine betaine content compared to untreated plants under drought conditions. Taken together, our results suggested EBR enhanced tolerance to drought in maize hybrids. Hence, pre-anthesis foliar application of EBR might partly overcome the adverse effects of flowering stage drought in maize. [ABSTRACT FROM AUTHOR]

Soil water scarcity hinders crop productivity globally, emphasizing the imperative for sustainable agriculture. This study investigated the role of nitrogen in alleviating drought stress in barley. Parameters such as relative water content, photosynthetic rate, stomatal conductance, mesophyll concentration of CO2, total leaf nitrogen, grain yield, total organic nitrogen content, starch content, and macronutrient concentrations (N, P, K, Ca, Mg) were examined. The optimal grain yield (3.73 t·ha−1) was achieved with 1 g of nitrogen per container (near 200 kg N hectare−1) under ideal moisture conditions. However, under drought stress, nitrogen supply variants (1 g and 2 g per container) exhibited a significant decrease in photosynthetic rate (Pn), NRA activities, and a notable increase in Ci values. Stomatal conductance exhibited a substantial decrease by 84% in the early growth phase, especially with a 2 g dose of nitrogen supply. Nitrogen enhanced crude protein levels, yet both drought stress and nitrogen application reduced grain weight and starch content. Nitrogen effectively improved metabolic processes under drought, particularly in earlier growth stages (e.g., tillering). This research highlights the importance of sustainable agricultural practices related to the growth stage of barley, emphasizing nitrogen optimization to enhance crop resilience in water-scarce environments. The results underscore the intricate interplay between nitrogen fertilization, drought stress, and crop yield, indicating benefits during initial stress exposure but detrimental effects in subsequent growth stages. [ABSTRACT FROM AUTHOR]

Objective: Water stress is a critical environmental factor, affecting the crucial processes and yield of crops. This study aimed to investigate the effect of water stress on the physiological and biochemical traits of safflower genotypes. Methods: The study was carried out as a factorial experiment based on a randomized complete block design at the Seed and Plant Improvement Research Institute during 2017-19. The treatments included two irrigation levels (40% and 80% depletion of the available water) and Parnian, Goldasht, and Kazak genotypes. The plants were sown in soil columns with a height of 150 and a diameter of 23 cm, and irrigated by a drip system. Antioxidant enzymes activity, malondialdehyde accumulation, proline, relative water content, chlorophyll, seed yield, and fatty acids composition were measured at the end of the experiment. Results: Water stress significantly increased the accumulation of hydrogen peroxide and malondialdehyde in safflower genotypes which led to increased catalase and peroxidase enzyme activity by 1 and 2.5 U, respectively. The proline content increased about 16 times under water stress conditions. In contrast, the relative water content showed a significant decrease, which resulted in increased canopy temperature and decreased seed yield by 70%. The Kazak genotype had the lowest increase in canopy temperature under stress conditions and showed higher yield stability. Moreover, the fatty acid composition of seed oil changed and the amount of linoleic acid decreased by 1.8% under water stress conditions. Conclusion: The results indicated that in addition to drought-related physiological traits, the lack of increase in saturated/unsaturated fatty acid ratio is also an important indicator in screening superior genotypes for cultivation under water shortage conditions. [ABSTRACT FROM AUTHOR]

Cadmium is one of the most carcinogenic and hazardous heavy metals on the earth for causes many serious diseases and disorders in the plant body. The presence of Cd in the soil is equally harmful to the production of rice crops and human beings. A pot experiment was conducted to analyze the consequences of cadmium-induced stress on the antioxidative defense system in rice plants. The assessment of antioxidative defense mechanism based on the cadmium-induced stress in the range of 100 to 300 ppm while the parameters, Chlorophyll Content Index (SPAD), nitrogen (%), relative water content (%), membrane stability index (%), proline content (µg.g-1), and catalase activity (nm H2O2 mg-1.min-1) were used. The highest reduction in the Chlorophyll Content Index (CCI), nitrogen (%), RWC (%), and MSI (%) was recorded at the highest concentrations of Cd Cl2 (300 ppm). However, at the same time, an increase in proline content (µg.g-1) and catalase activity (nm H2O2 mg-1. min-1) were also detected at all the intervals of the study. The activity of CCI, amino acid, and enzyme were presented in % increase/decrease over the control of Cd-induced stress in rice plants. The reduction (%) in CCI (SPAD) and RWC (%) was recorded maximum at 75 Days after transplanting (DAT), while nitrogen (%) and MSI (%) were recorded at 50 DAT. However, the increase (%) in proline and Catalase activity was maximum at 75 and 50 DAT. [ABSTRACT FROM AUTHOR]

Drought stress poses a significant threat to Brassica napus (L.), impacting its growth, yield, and profitability. This study investigates the effects of foliar application of individual and interactive pharmaceutical (Paracetamol; 0 and 250 mg L−1) and amino acid (0 and 4 ml/L) on the growth, physiology, and yield of B. napus under drought stress. Seedlings were subjected to varying levels of drought stress (100% field capacity (FC; control) and 50% FC). Sole amino acid application significantly improved chlorophyll content, proline content, and relative water contents, as well as the activities of antioxidative enzymes (such as superoxide dismutase and catalase) while potentially decreased malondialdehyde and hydrogen peroxide contents under drought stress conditions. Pearson correlation analysis revealed strong positive correlations between these parameters and seed yield (R2 = 0.8–1), indicating their potential to enhance seed yield. On the contrary, sole application of paracetamol exhibited toxic effects on seedling growth and physiological aspects of B. napus. Furthermore, the combined application of paracetamol and amino acids disrupted physio-biochemical functions, leading to reduced yield. Overall, sole application of amino acids proves to be more effective in ameliorating the negative effects of drought on B. napus.

Adaptability and significant economic value of the neem tree are well-known, as it can flourish in a variety of environmental conditions. While the neem seed production is highly sensitive to prevailing weather conditions during the reproductive phase and flowering behaviour of the tree. A study was conducted at Tamil Nadu Agricultural University, Coimbatore in 2023 with the primary objective of validating the weather influence on neem seed production using the logics of physiological responses, as a continuation of research conducted the previous year (2022). During the pre-flowering and flowering stages, diverse weather conditions led to notable changes in the physiological traits of neem trees, which displayed varying patterns of flowering. Trees that flowered consistently showed elevated levels of indole acetic acid (IAA) oxidase, relative water content, and nitrate reductase compared to those that lacked flowers or produced intermittently. In the flowering stage, the neem trees responded positively in terms of physiological aspects like IAA oxidase, relative water content, nitrate reductase, and exhibited lower proline levels, which can be attributed to the optimal maximum temperature, rainfall, and soil moisture. Proline levels rose during the pre-flowering stage due to soil moisture deficits but fell during the flowering stage with the onset of rain. These physiological changes, driven by climatic factors, are likely to enhance the flowering, fruiting, and overall yield of neem trees.

Drought is the most important abiotic stress in arid and semi-arid regions of the world and causes a decrease in the yield of agricultural plants. One of the ways to deal with drought is the use of hydrogels. Two pot experiments were conducted to study the effect of hydrogel polymer on the growth and the physiological traits of fenugreek and dill plants. The study was carried out as a factorial experiment in a completely randomized design. The experiment included two factors: hydrogel polymer rates (0, 0.02, 0.04, and 0.08 grams per kilogram of soil) and irrigation intervals (irrigation intervals of 3 and 6 days). Results showed that leaf, stem and seedling fresh and dry weight were increased by hydrogel polymer application in both plant species. Hydrogel polymer increased leaf relative water content but decreased chlorophyll content. Plants treated with the polymer applied at 0.08 g kg -1 produced the highest dry matter. The improvement was probably due to the increased leaf relative water content. The highest dry weight of the seedling was measured in plants treated with the polymer applied at 0.08 g kg-1 , whereas the lowest seedling dry weight was found in plants that were not treated with the polymer. The effect of irrigation interval on growth characteristics of both plant species was not significant. Overall, the use of hydrogel improves plant biomass in dill and fenugreek. Application of amounts higher than 0.08 g/kg of hydrogel on dill and fenugreek is recommended for further research.

IntroductionLavender (Lavandula officinalis L.) belonging to the Lamiaceae family is a plant with economic, medicinal and ornamental value. Its essential oil is used as a raw material for many industries, including perfumery, cosmetics, and pharmaceutical industries. Drought stress as a limiting factor reduces growth and productivity in plants. This issue is especially important in arid and semi-arid regions of the world such as Iran. One of the basic solutions to adjust or reduce the effect of water stress in agricultural plants is the use of different types of biological fertilizers. Also, its low diffusion speed in the soil can play an important role in the lack of its ions in the solution in the soil of the root development area. In most agricultural systems, due to the low mobility of phosphorus in the soil, absorption by the plant is low. In order to investigate the effect of biofertilizers and phosphorus on reducing the effects of irrigation deficiency in lavender, an experiment was conducted in the form of split plots in a randomized complete block design with 3 replications at the Research Station of the Faculty of Agriculture, Islamic Azad University of Tabriz in 2019-2020.Materials and methodsExperimental factors including irrigation levels (irrigation after 60, 90 and 120 mm from Class A evaporation pan) as the main factor and inoculation with biofertilizer including four levels (inoculation with Thiobacillus, Pseudomonas and Thiobacillus + Pseudomonas and no inoculation As control) and phosphorus fertilizer levels at two levels (0 and 50 kg ha-1) as a secondary factor. The studied traits included leaf dry weight, flower dry weight, cell membrane leakage rate, relative leaf water content, soluble sugars and proline content, catalase and superoxide dismutase enzymes and peroxidase and MDA. To measure the activity of antioxidant enzymes, leaf samples kept at -80 degrees Celsius were used. The activity of catalase was measured using the method described by (Aebi, 1984; Ezhilmathi, 2007). The measurement of superoxide dismutase (SOD) enzyme was calculated according to the method (Giannopolitis and Ries, 1977) based on enzyme unit per milligram per body weight. The determination of malondialdehyde (MDA) was based on Aston and Sidney's method (Aston and Sidney, 1987). Proline content in the youngest leaf was also determined by the method of Bates et al. (1973). SAS version 8 software was used to analyze the variance of the data, MSTATC version 2 software was used to compare the averages, and Excel software was used to draw the figures.Results and discussionThe results showed that at all levels of irrigation, phosphorus consumption and inoculation with integrated biofertilizers increased the dry weight of flowers compared to the control. Irrigation after 60 mm of evaporation from the pan with the application of 50 kg of phosphorus per hectare and application of Thiobacillus + Pseudomonas obtained the highest dry weight of flowers (833.3 g ha-1). The highest leaf dry weight was proline, catalase, peroxidase, superoxide dismutase and malondialdehyde at 60 ml of evaporation with 50 kg ha-1 application and application of Thiobacillus + Pseudomonas. The results of this study also showed that the effects of interaction between irrigation, phosphorus and biofertilizer levels on cell membrane leakage, leaf dry weight and relative leaf water content were not significant.ConclusionBased on the results of this experiment, it can be said that in water stress conditions, the use of biological fertilizers combined with the use of phosphorus fertilizers can greatly reduce the incidence of malnutrition in lavender medicinal plant. The accumulation of soluble sugars, proline and the increase in the activity of antioxidant enzymes in this plant in the face of drought stress can be considered as drought tolerance mechanisms. The combined use of Thiobacillus and Pseudomonas bacteria had better results than the use of these bacteria alone; Therefore, if the intensity of water deficit stress in this plant is not high, the effects of water deficit stress can be reduced by using biological fertilizers and phosphorus fertilizer.

Common bean is a species having high nutritional composition. Drought response in plants is complex phenomenon relating interactions between structure, functions and development of the plant. The Improvement of drought resistant for common bean has major objectives for many breeding programs. The growth of the plant, related to the parameter plays a vital role in the selection criteria for drought resistance. The increasing drought tolerance in commercial varieties is highly desirable. 20 varieties of common bean leaves were collected, it is subjected in vitro water stress with 10% polyethylene glycol 6000 (PEG 6000). The parameters are determined as a relative water content (RWC), seedling root length, leaf area, stomatal index, wax and proline. The result points out that these varieties responded differently during the drought stress. Tolerant and Susceptible comes under the varieties that are categorized which are based on RWC. The tolerant varieties maintain a high water content. Generally, the tolerant varieties are higher in seedling root length, leaf area, stomatal index, wax than the susceptible varieties. The proline accumulations are higher in susceptible varieties when compared to the tolerant varieties. A significant correlation was observed from the above parameters. The results are discussed with reference to the plant’s response during drought.

Glucan phosphorylase is present in plants in two isozymes, namely, a plastidial isoform (PHO1) and a cytosolic isoform (PHO2), and is involved in starch-related carbohydrate metabolism. The aim of this study was to determine whether mutations in the genes encoding glucan phosphorylase caused these plants to have increased resistance to short-term drought. One of the strategies plants use to defend themselves against drought stress is to change their starch content, which may be due to changes in glucan phosphorylase activity. In our greenhouse pot experiment, we used potato leaves from wild-type plants and transgenic mutant lines with reduced expression of genes encoding both PHO isozymes. The plants were exposed to drought or were grown under optimal conditions. A lack of water strongly affected the water saturation deficit (WSD) and leaf protein content. The activity of the plastidial glucan phosphorylase isoform (PHO1) in mutant plants increased under drought stress, in contrast to its activity in wild-type plants. After analyzing several physiological parameters, we found that suppressed expression of the gene encoding one of the subunits of plastidial glucan phosphorylase, PHO1a, resulted in increased tolerance to drought in potatoes.

Drought is a significant climatic factor that significantly affects the production of Chinese cabbage, a crop that is highly susceptible to drought stress. The development and cultivation of drought-tolerant varieties could be a viable strategy to minimize the damage caused by climate change and ensure stable production of Chinese cabbage. This requires the implementation of technologies for early evaluation and selection of a plethora of resources. In this study, we screened 100 varieties and breeding resources for drought tolerance under a water deficit treatment at the seedling stage. We also evaluated the growth response of Chinese cabbage varieties and breeding resources under water deficit treatment and selected drought-tolerant Chinese cabbage genotypes. We confirmed that the visual score for wilting, which evaluates the wilting response during the recovery process of Chinese cabbage seedlings through water deficit treatment and re-watering, can be used as an indicator for evaluating tolerance to drought stress. The visual score for wilting showed a high correlation with major traits representing drought tolerance. Our findings highlight the need for an integrated approach that considers various environmental conditions, varieties, and lines to select and develop drought-tolerant varieties. We selected '18-FH112-1' and '18-FH112-1-2' among others, and these germplasms will be useful resources for drought tolerance breeding. This study provides a foundation for future efforts to develop drought-tolerant Chinese cabbage varieties, thereby contributing to the stable production of this crucial crop. [ABSTRACT FROM AUTHOR]

Osteospermum ecklonis DC. NORL. is native to South Africa and is fully adapted to the Mediterranean climate. The aim of the study was to elucidate morphological and developmental changes in O. ecklonis plants associated with drought resistance in response to low doses of UV-C. Growth responses under three levels of drought stress (NW: normal watering, MD: moderate drought stress and SD: severe drought) were recorded. The results showed that 1 kJ m−2 UV-C significantly (p < 0.05) increased resistance to water stress without affecting growth and development or damaging photosystem II. Fresh weights of the upper parts and the root system of the irradiated plants were maintained at similar levels to those of the non-irradiated control plants. Fv/Fm values in the irradiated plants ranged from 0.73 to 0.82 depending on the stress level, while in the non-irradiated plants, the values ranged from 0.69 to 0.83. Differences between UV-C irradiated and non-irradiated plants were recorded in electrolyte leakage (EL), in malondialdehyde (MDA) and in relative water content (RWC) at all drought levels. The EL percentage of the non-irradiated plants at SD was 19.7%, while in the irradiated plants, it was 17.8%. RWC rates in the irradiated plants ranged between 60.6 and 76.4%, while in the non-irradiated plants, they ranged from 54.2 to 63.6%. Superoxide dismutase (SOD) and catalase (CAT) activities increased with UV-C irradiation, suggesting that antioxidant responses were induced and protected cell membranes from lipid peroxidation and damage. The results of the present study showed that UV-C irradiation at 1 kJ m−2 alleviated the drought symptoms of O. ecklonis by reducing oxidative stress and membrane lipid peroxidation. [ABSTRACT FROM AUTHOR]

Oat (Avena nuda L.) is a globally important cereal crop grown for its nutritious grains and is considered as moderately salt-tolerant. Studying salinity tolerant mechanisms of oats could assist breeders in increasing oat production and their economic income in salt-affected areas, as the total amount of saline land in the world is still increasing. The present study was carried out to better understand the salt tolerance mechanism of the naked oat line Bayou1. A soil experiment was conducted on 17 days-old Bayou1 seedlings treated with varying concentrations of NaCl for a period of 12 days. Bayou1 plants grew optimally when treated with 50 mM NaCl, demonstrating their salinity tolerance. Reduced water uptake, decreased Ca2+, Mg2+, K+, and guaiacol peroxidase activity, as well as increased Na+ concentration in leaves, all contributed to a reduction in shoot growth. However, the damage to ionic homeostasis caused by increased Na+ concentrations and decreased K+ concentrations in the roots of Bayou1 did not inhibit its root growth, indicating that the main salt-tolerant mechanism in Bayou1 existed in its roots. Further, a hydroponic experiment found that increasing Na+ concentration in root cell sap enhanced root growth, while maintaining the integrity of root cell membranes. The accumulated Na+ may have facilitated the root growth of Bayou1 exposed to NaCl by effectively adjusting cellular osmotic potential, thereby ensuring root cell turgor and expansion. [ABSTRACT FROM AUTHOR]