Water Deficit Stress Research Articles

Effects of Water Deficit Stress at the Tillering Stage of Direct Seeded Rice (Oryza sativa L.)

The ten rice varieties viz. NAUR-1, Purna, GNR-6, NVSR-2227, NVSR-3093, NVSR-2285, NVSR-2278, NVSR-2852, NVSR-2601, and NVSR-2927 were grown in kharif season for observing their efficiency in terms of yield under a deficit of water at tillering stage. The effects of short-term water stress on various morpho-physiological and biochemical traits viz. leaf area index, number of panicles, chlorophyll content, number of stomata, relative water content, abscisic acid, proline, glycine betaine, ascorbic acid, and harvest index content were studied and they were observed higher in Purna as compared to other nine varieties. However, Plant height and Ionic leakage were recorded lower in Purna as compared to other varieties. The abscisic acid as well as proline and glycine betaine content recorded maximum in Purna which might help in keeping hydration in cells during water deficit stress. Thus, with short-term water deficit stress at tillering stage, the variety Purna would be better in terms of breeding for tolerant variety as well as yield among ten rice varieties.

Root responses under water deficit stress: unraveling the impact on wheat crop and the ameliorating role of brassinolide

Aim: To identify changes in root system architecture traits of wheat due to exogenous application of epibrassinolide for the alleviation of negative impact of low moisture stress in wheat crop. Methodology: On the basis of growth performances one set of contrasting wheat genotypes were identified (HD-2733, relatively stress tolerant and DBW-187 relatively stress sensitive). Similarly, brassinosteroids (BRs) concentration was selected by pilot experiments, wherein 0.01mM performed best among all. Taking all these results into consideration, four treatments (T0=well-watered, T1=water deficit, T3=EBL + well wateredandT4=EBL + water deficit) were maintained for evaluation of root architectural traits, biomassand grain yield per plant. Results: The tolerant genotype (HD-2733) showed better tolerance in almost all root traits and in yield as compared to the sensitive genotype (DBW-187). epibrassinolide under water deficit condition was found to be effective as the root trait values were higher for root length, root volume, root surface area and root biomass under EBL+ water deficit treatment as compared to water deficit. Shoot biomass was highly sensitive to water deficit as the biomass allocation under water deficit was more towards root as compared to shoot. Interpretation: Epibrassinolide can be a potent biochemical to improve the root characteristics as well as yield per plant. Seeds of tolerant genotype treated with 0.01m M EBL even under low moisture stress can be recommended. Key words: Epibrassinolide, Root system, Wheat, Water deficit

Physiological and Morphological Responses of Three Grapevine Rootstocks to Water Stress

Water deficit stress is one of the most frequent environmental stresses affecting the physiological and growth responses of plants, especially grapevines. However, grapevine varieties and species differ in their tolerance to water stress. To identify the most tolerant grapevine rootstock, a factorial randomised block design with two factors was used. The first factor included the susceptible cv. Sultana (V. vinifera L.) scion grafted onto three rootstocks (Yaghouti, Kolahdari and 140 Ru), and the second factor was water stress potential at three levels (control, -1 MPa and -2 MPa). The physiological parameters, such as malondialdehyde (MDA), electrical leakage (EL), proline, soluble sugar, protein, photosynthetic pigments, and antioxidant enzymes were investigated. Our results revealed that increasing water stress enhanced H2O2, MDA, EL, proline, soluble sugar, and soluble protein, while decreasing chlorophyll (Chl) and carotenoid contents, growth parameters, and plant dry weight. The glutathione peroxidase (GPX) activity was enhanced in response to water deficiency, whereas catalase (CAT) and ascorbate peroxidase (APX) enzymes exhibited higher activity at -1 MPa, which was then reduced under the lowest water potential (-2 MPa). In addition, 140 Ru rootstocks exposed to water stress had lower levels of MDA, H2O2, EL, and higher Chl (a, b), carotenoid, APX, and GPX activity, as well as higher shoot dry weight. Overall, the physiological and morphological responses of the three rootstocks propose that grafting the commercial Sultana cultivar onto drought-tolerant rootstocks such as 140 Ru is an effective strategy for improving drought stress tolerance.

Investigation of Benzyl Adenine and Water Deficit Stress on Antioxidant Enzyme Activities in Peanut (Arachis hypogaea L.)

Investigation of Benzyl Adenine and Water Deficit Stress on Antioxidant Enzyme Activities in Peanut (Arachis hypogaea L.)

Deciphering the physio-biochemical dynamics of wheat (T. aestivum L.) genotypes during water deficit stress

Deciphering the physio-biochemical dynamics of wheat (T. aestivum L.) genotypes during water deficit stress

Evaluation of Agronomical traits and Drought Tolerance Indices in Some Corn (Zea mays L.) Hybrids under Water Deficit Stress

Evaluation of Agronomical traits and Drought Tolerance Indices in Some Corn (Zea mays L.) Hybrids under Water Deficit Stress

Enhanced photochemical efficiency of PSII in Prosopis juliflora suggests contribution to invasion advantage over native C3 xero-halophytes under salt stress.

Chlorophyll a fluorescence parameters related to PSII photochemistry, photoprotection and photoinhibition were investigated in four C3 plant species growing in their natural habitat: Prosopis juliflora ; Abutilon indicum ; Salvadora persica ; and Phragmites karka . This study compared the light reaction responses of P. juliflora , an invasive species, with three native co-existing species, which adapt to varying water deficit and high salt stress. Chlorophyll a fluorescence quenching analyses revealed that P. juliflora had the highest photochemical quantum efficiency and yield, regulated by higher fraction of open reaction centres and reduced photoprotective energy dissipation without compromising the integrity of photosynthetic apparatus due to photoinhibition. Moreover, the elevated values of parameters obtained through polyphasic chlorophyll a fluorescence induction kinetics, which characterise the photochemistry of PSII and electron transport, highlighted the superior performance index of energy conservation in the transition from excitation to the reduction of intersystem electron carriers for P. juliflora compared to other species. Enhanced pigment contents and their stoichiometry in P. juliflora apparently contributed to upregulating fluxes and yields of energy absorbance, trapping and transport. This enhanced photochemistry, along with reduced non-photochemical processes, could explain the proclivity for invasion advantage in P. juliflora across diverse stress conditions.

Rhizobacteria Bacillus spp. mitigate osmotic stress and improve seed germination in mustard by regulating osmolyte and plant hormone signaling.

Drought, a widespread abiotic stressor, exerts a profound impact on agriculture, impeding germination and plant growth, and reducing crop yields. In the present investigation, the osmotolerant rhizobacteria Bacillus casamancensis strain MKS-6 and Bacillus sp. strain MRD-17 were assessed for their effects on molecular processes involved in mustard germination under osmotic stress conditions. Enhancement in germination was evidenced by improved germination percentages, plumule and radicle lengths, and seedling vigor upon rhizobacterial inoculation under no stress and osmotic stress conditions. Under osmotic stress, rhizobacteria stimulated the production of gibberellins and reserve hydrolytic enzymes (lipases, isocitrate lyase, and malate synthase), bolstering germination. Furthermore, these rhizobacteria influenced the plant hormones such as gibberellins and abscisic acid (ABA), as well as signalling pathways, thereby promoting germination under osmotic stress. Reduced proline and glycine betaine accumulation, and down-regulation of transcription factors BjDREB1_2 and BjDREB2 (linked to ABA-independent signalling) in rhizobacteria-inoculated seedlings indicated that bacterial treatment mitigated water deficit stress during germination, independently of these pathways. Hence, the advantageous attributes exhibited by these rhizobacterial strains can be effectively harnessed to alleviate drought-induced stress in mustard crops, potentially through the development of targeted bio-formulations.

Investigating the Stability of Bread Wheat Genotypes under Water Deficit Stress Conditions in Different Cold Climate Regions of using AMMI and GGE-Biplot Analysis

Investigating the Stability of Bread Wheat Genotypes under Water Deficit Stress Conditions in Different Cold Climate Regions of using AMMI and GGE-Biplot Analysis

Performance of mungbean (Vigna radiata L. Wilczek) accessions under intermittent water deficit stress in a tropical environment

Performance of mungbean (Vigna radiata L. Wilczek) accessions under intermittent water deficit stress in a tropical environment

Impact of Bio-Fertilizers under Supplementary Irrigation and Rain-fed Conditions on Some Physiological Responses and Forage Quality of Smooth Vetch (Vicia dasycarpa L.)

The purpose of this study was the evaluate use of bio-fertilizers to adjustment water shortage stress and improved smooth vetch (Vicia dasycarpa L.) yield under water deficit stress conditions. Thus, A 2-year experiment were performed in an agrisilviculture system of plum orchard in 2016 and 2017. In this study, the single, double and triple combined of Arbuscular mycorrhizal fungi- Rhizophagus intraradices (AMF), Azotobacter chroococcum (Az) and Thiobacillus spp. (Th) on smooth vetch plants were evaluated under rain-fed and supplemental irrigation. The results indicated that irrigated plants had more Fe and Zn nutrients than rain-fed plants. Combined use of AMF + A. chroococcum more improved the forage dry matter digestibility (DMD), total digestible nutrient (TDN), net energy for lactation (NEL), dry matter intake (DMI) and relative feed value (RFV) than plants with single inoculation. In irrigated plants, double and triple combination of AMF with A. chroococcum and/or Thiobacillus spp. improved chlorophyll-a, chlorophyll-b, total chlorophyll, RWC, TSS, AsA, and GSH while lowering proline and MDA. Rain-fed condition reduced grain yield. In conclusion, synthesis non-enzymatic antioxidant because of the combined use of bio-fertilizers (AMF, Az and Th) can reduce ROS damage and improve water deficit resistance and yield in smooth vetch rain-fed plants.

Physiological and biochemical responses of rice to polyethylene glycol

Effects of water deficit induced by polyethylene glycol (PEG-6000) on rice grown in half strength Hoagland solution was studied in the present investigation. Impacts of different water stress (10, 20 and 30% PEG) on some physiological and biochemical characteristics were determined in this investigation. Results showed that water stress significantly affected most physiological and biochemical characteristics. The increasing water stress declined the root and shoot length and fresh and dry weights of root and shoot. An increase in water stress also resulted in reduction of relative water content, leaf pigments and protein content. Upon dehydration, an incline in reducing and total sugar and proline content were evident in the root and shoot of rice. Water-deficit stress resulted in higher superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities but as the severity of the water stress increased, the SOD activity decreased. These crucial characteristics would be expected to be utilized as screening techniques for water stress tolerance to the future development of new variety. Bangladesh J. Bot. 52(4): 897-905, 2023 (December)

Soil Manuring and Genetic Variation Conjunctively Surmount the Partial Drought Stress in Wheat (Triticum aestivum L.)

Crop growth is negatively influenced under water-stress conditions, which is among the most yield-limiting factors significantly decreasing crop yield. This study evaluated the effect of water-deficit stress on physiological, bio-chemical and yield attributes of wheat (Triticum aestivum L.) under both constantly wet and water-stressed conditions on two wheat varieties (UJALA-14, SARC-4). Further, the combined impacts of crop genetic variability and organic manuring in soil was studied for overcoming the partial drought stress in wheat. Treatments of different levels of irrigation water alone or with farmyard manure (FYM) @ 20 Mg ha‒1 were compared as: constantly wet irrigation (control), irrigation intensity equal to field capacity (FC), ½ FC + FYM, and ¼ FC + FYM. Crop growth, physiological and chlorophyll as well as sodium and potassium contents were measured. The findings of current study exhibited that shortage of water had negative effects on growth, physiological, bio-chemical and yield attributes of wheat. Genotype SARC-4 exhibited superior growth response having constantly wet and field capacity condition, on the other hand UJALA-14 gave better growth response under water stress conditions of ½ FC and ¼ FC when treated with FYM amendment. It is concluded that partial drought stress developed tolerance in wheat genotypes particularly in UJALA-14, which was strengthened with organic amendment. Combined use of drought tolerant varieties and application of FYM as a fertilizer is very effective way to enhance crop yield.

Water availability may not constrain vegetation growth in Northern Hemisphere

With global climate warming, the variability of climate and weather tends to increase driving the water resources available for vegetation become more uncertain. Therefore, there is still a debate as to how vegetation response to, and to which extent it is constrained to water availability. In this study, we analyzed the correlation between vegetation growth and water availability in the Northern Hemisphere from 1982 to 2018. The condition of vegetation growth was characterized by Normalized Difference Vegetation Index (NDVI) and Leaf Area Index (LAI), while the Standardized Precipitation Evapotranspiration Index (SPEI) represented water condition. Our results suggest that the water deficit stress on vegetation growth in the Northern Hemisphere caused by global warming may not be as severe as described in previous studies. Although there was an increasing trend in areas where vegetation growth was constrained by water deficit in the Northern Hemisphere, such trend was not significant; in contrast, there was a significant decreasing trend in areas where vegetation growth was constrained by surplus water. In addition, there was a spatial variability in water availability for vegetation growth at mid and high latitudes. We further found that the response time of vegetation to both water deficit and water surplus was increasing, indicating that the cumulative effect of water availability on vegetation growth was delaying, and that vegetation tends to be affected by climatic extreme events such as drought with longer time scales. Our results highlight the need to reconsider the response of vegetation activities to water availability, and shed light on a more divers reaction pattern of vegetation to water in the context of climate change.

Unlocking the Genetic Basis of Abiotic Stress Tolerance in Wheat: Insights from Dif- ferential Expression Analysis and Machine Learning

Abiotic stresses such as heat and cold temperatures, salinity, and drought are threatening global food security by affecting crop quality and reproductivity. Wheat is the most essential staple crop in the world, its complex genome is the main barrier to finding valuable genes responsive to different stresses. Thus, in our study we conducted differential RNA-seq analysis to identify Differentially Expressed Genes (DEGs) involved in 4 different stresses such as drought, heat, freeze resistance, and water-deficit stress, then applied two machine learning models; the "Extra-tree regressor" and LIME algorithms to accurately predict and select the highly significant genes. Our findings identified a set of 36 significant genes, many of which play important roles in various molecular functions, cellular components, and biological processes related to the response or resistance to abiotic stress in wheat. For example, Hsp101b is a member of the heat shock protein family, which protects cells against stress by stabilizing proteins. BADH, an enzyme involved in the synthesis of stress hormones, is important for the plant’s response to different stresses. AGL14 is a member of the AGL protein family, which regulates gene expression and is involved in the plant’s response to drought, cold, and salinity stresses. This study demonstrates the prospects of the integration of bioinformatics tools as well as machine learning models to assess the genes responsible for wheat stress resistance, genes’ regulatory networks, and their functions in order to save time and cost to improve wheat productivity.

Effects of zinc-nano oxide, salicylic acid and sodium nitroprusside on physiological properties, antioxidant enzyme activities and secondary metabolites of Viola odorata under drought stress

One of the most important abiotic stresses and limiting factors (closing pores, lack of CO2 entry, reduced photosynthesis, and reduced yield) of plant products around the world is water-deficit stress. This study aimed to examine the water deficit stress and foliar application with anti-stress compounds (ASC) on characteristics of Viola odorata. The study was carried out as a factorial experiment based on a randomized complete design. The factors consisted of water deficit and the foliar application of ASC at six levels [zinc-nano oxide (ZnO, 1000 and 1500 mg l–1), salicylic acid (SA, 200 and 300 mg l–1), and sodium nitroprusside (SNP, 200 and 300 μM)], and the control. The water deficit reduced the leaf water potential, cell membrane stability, and the shoot and root fresh weight but increased electrolyte leakage and soluble sugar accumulation. However, foliar applications, particularly SA and SNP, positively affected the measured parameters. The activities of superoxide dismutase and guaiacol peroxidase at all three field capacity levels were higher in the plants treated with SA and SNP than in the control and plants treated with ZnO. In sum, using 200 mg l–1 of SA as a foliar application, in addition to improvement of the growth and developmental conditions of the aromatic violet plant, moderated the adverse effects of water deficit stress and increased the plant resistance to water deficit stress. Based on the results, the application of SA, SNP, and ZnO reduced electrolyte leakage and enhanced the plant’s resistance to water deficit by increasing the compatible osmolyte accumulation and antioxidant enzyme activity.

Integrative impacts of salicylic acid and water deficit stress on physiological processes of medicinal herb Bacopa monnieri (L.)

Integrative impacts of salicylic acid and water deficit stress on physiological processes of medicinal herb Bacopa monnieri (L.)

Stem water potential estimation from images using a field noise-robust deep regression-based approach in peach trees

Field-grown peach trees are large and have a complex branch structure; therefore, detection of water deficit stress from images is challenging. We obtained large datasets of images of field-grown peach trees with continuous values of stem water potential (Ψstem) through partial secession treatment of the base of branches to change the water status of the branches. The total number of images as frames extracted from videos of branches was 23,181, 6743, and 10,752, in the training, validation, and test datasets, respectively. These datasets enabled us to precisely model water deficit stress using a deep-learning-regression model. The predicted Ψstem of frames belonging to a single branch showed a Gaussian distribution, and the coefficient of determination between the measured and predicted values of Ψstem increased to 0.927 by averaging the predicted values of the frames in each video. This method of averaging the predicted values of frames in each video can automatically eliminate noise and summarize data into the representative value of a tree and is considered to be robust for the diagnosis of water deficit stress in large field-grown peach trees with a complex branch structure.

Real-time expression and in silico characterization of pea genes involved in salt and water-deficit stress

Real-time expression and in silico characterization of pea genes involved in salt and water-deficit stress

Effect of water deficit stress during fruit cultivation on the carbon stable isotopes of organic acids in Japanese apricots and liqueur prepared from these fruits

ABSTRACT The objective of this study was to assess the impact of water deficit stress during fruit cultivation on the δ 13C values of citric acid and malic acid in Japanese apricots at different ripeness stages and their resulting liqueurs. Our experiments show that water deficit stress increases the δ 13C values of citric acid and malic acid in tree-ripened fruits, counteracting the typical decrease during ripening. However, water deficit treatment has a minimal effect on the δ 13C values of organic acids in green fruits. Regardless of fruit ripeness or water status, the δ 13C values of organic acids in fruits are directly reflected in the resulting liqueurs. Overall, water deficit stress during fruit cultivation has the potential to promote similarity in the δ 13C values of organic acids across fruits at different ripeness levels, reducing variations among liqueurs derived from fruits of varying ripeness levels.