Drought Stress Impacts on Plants and Different Approaches to Alleviate Its Adverse Effects

Drought stress, being the inevitable factor that exists in various environments without recognizing borders and no clear warning thereby hampering plant biomass production, quality, and energy. It is the key important environmental stress that occurs due to temperature dynamics, light intensity, and low rainfall. Despite this, its cumulative, not obvious impact and multidimensional nature severely affects the plant morphological, physiological, biochemical and molecular attributes with adverse impact on photosynthetic capacity. Coping with water scarcity, plants evolve various complex resistance and adaptation mechanisms including physiological and biochemical responses, which differ with species level. The sophisticated adaptation mechanisms and regularity network that improves the water stress tolerance and adaptation in plants are briefly discussed. Growth pattern and structural dynamics, reduction in transpiration loss through altering stomatal conductance and distribution, leaf rolling, root to shoot ratio dynamics, root length increment, accumulation of compatible solutes, enhancement in transpiration efficiency, osmotic and hormonal regulation, and delayed senescence are the strategies that are adopted by plants under water deficit. Approaches for drought stress alleviations are breeding strategies, molecular and genomics perspectives with special emphasis on the omics technology alteration i.e., metabolomics, proteomics, genomics, transcriptomics, glyomics and phenomics that improve the stress tolerance in plants. For drought stress induction, seed priming, growth hormones, osmoprotectants, silicon (Si), selenium (Se) and potassium application are worth using under drought stress conditions in plants. In addition, drought adaptation through microbes, hydrogel, nanoparticles applications and metabolic engineering techniques that regulate the antioxidant enzymes activity for adaptation to drought stress in plants, enhancing plant tolerance through maintenance in cell homeostasis and ameliorates the adverse effects of water stress are of great potential in agriculture.

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Improving water stress tolerance of the biocontrol yeastCandida sakegrown in molasses-based media by physiological manipulation

Canadian Journal of Microbiology ◽

10.1139/w00-138 ◽

2001 ◽

Vol 47 (2) ◽

pp. 123-129 ◽

Cited By ~ 5

Author(s):

M Abadias ◽

N Teixidó ◽

J Usall ◽

I Viñas ◽

N Magan

Keyword(s):

Polyethylene Glycol ◽

Water Stress ◽

Amino Acid ◽

Cell Viability ◽

Stress Tolerance ◽

Biocontrol Agent ◽

Compatible Solutes ◽

Intracellular Concentration ◽

Water Stress Tolerance ◽

Candida Sake

The biocontrol agent Candida sake was cultured on either an unmodified molasses-based medium (water activity, aw0.996) or on water stressed media produced by the addition of glycerol, glucose, NaCl, sorbitol, or proline to 0.98, and 0.96 awfor 24, 48, and 72 h, to study their impact on subsequent cell viability, and on concentrations of endogenous sugars (trehalose and glucose) and polyols (glycerol, erythritol, arabitol, and mannitol). The viability of cells of different ages cultured on these media was evaluated on NYDA medium with freely available water (aw0.995), and on medium modified with polyethylene glycol to aw0.95. Regardless of solute used, viable counts of cells grown on molasses-based medium (aw0.98) were equal to or higher than those obtained from the medium with water freely available. The amino acid proline stimulated growth at 10% concentration. In contrast, water stress induced by addition of NaCl, glucose, or sorbitol at aw0.96 caused a significant reduction in viable counts. Older cultures were more resistant to water stress. Glycerol and arabitol were the main solutes accumulated by C. sake cells in response to lowered aw. Intracellular concentration of these polyols depended more on the solute used to adjust the awthan on the awitself. Candida sake was more resistant to water stress with higher intracellular concentration of glycerol and erythritol.Key words: compatible solutes, polyols, sugars, improved viability, formulation.

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Improvement of drought tolerance in rice using line X tester mating design and biochemical molecular markers

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00656-1 ◽

2022 ◽

Vol 46 (1) ◽

Author(s):

Almoataz Bellah Ali El-Mouhamady ◽

Abdul Aziz M. Gad ◽

Ghada S. A. Abdel Karim

Keyword(s):

Water Stress ◽

Drought Stress ◽

Drought Tolerance ◽

Stress Tolerance ◽

Water Deficit ◽

Scientific Progress ◽

Crop Productivity ◽

Hybrid Generation ◽

Water Stress Tolerance ◽

Rice Genotypes

Abstract Background Water stress, specifically the limited water resources needed to grow strategic crops, especially rice, poses a great threat to crop productivity. So, it was imperative that scientists all work together to try genetically improving the rice for drought tolerance in light of these environmental challenges. The aim of this study is trying to know the genetic behavior responsible for water-deficit tolerance in rice genotypes but at the molecular level. Moreover, this attempt will be an important leap in the process of genetic improvement in rice for water stress tolerance in Egypt. Results Twenty-three rice genotypes including eight parents and their fifteen F1 crosses or (the first hybrid generation) by line X tester analysis were evaluated for water stress tolerance during two experiments (the control and drought experiment) besides some molecular–biochemical studies for eight parents and the highest selected five crosses for water stress tolerance. The research revealed that five rice crosses out of fifteen hybrids were highly tolerant to water stress compared to the normal conditions. Data of biochemical markers indicated the presence of bands that are considered as molecular genetic markers for water-deficit tolerance in some rice genotypes, and this is the scientific progress achieved in this research. This was evident by increasing the density and concentration of SDS-protein electrophoresis besides enhancing the activities of peroxidase (POD) and polyphenol oxidase (PPO) under water-deficit conditions, which confirmed the tolerance of drought stress in the eight rice genotypes and the best five crosses from the first hybrid generation. Conclusion The five promising and superior rice hybrids showed an unparalleled tolerance to water stress in all evaluated traits under water stress treatment compared to the standard experiment. Also, biochemical and molecular parameters evidence confirmed the existence of unquestionable evidence that it represents the main nucleus for producing rice lines tolerated for drought stress under Egyptian conditions.

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Stomatal and physiological response of contrasting Z. mauritiana (Lamk.) clones to water stress

10.1101/077297 ◽

2016 ◽

Author(s):

M. Kulkarni

Keyword(s):

Water Stress ◽

Drought Stress ◽

Stress Tolerance ◽

Fruit Production ◽

Relative Increase ◽

Leaf Temperature ◽

Fruit Drop ◽

Water Stress Tolerance ◽

Relative Water ◽

Leaf Relative Water Content

AbstractWater stress is one of the major limitations to fruit production worldwide. Identifying suitable indicators, screening techniques and quantifiable traits would facilitate the genetic improvement process for water stress tolerance. In the present study, we evaluated the ability of physiological parameters (Transpiration, E; Fv/Fm; leaf water potential, ψleaf; leaf temperature, LT; and, leaf relative water content, RWC) to distinguish between contrasting Z. mauritiana clones subjected to a 30-d drought cycle. Four field-grown clones Seb and Gola (tetraploid) and Q 29 and B 5/4 (diploid) were studied. By 30 d after the onset of water stress treatment, the E, Fv/Fm, ψleaf and RWC of drought-stressed plants had declined significantly in all genotypes compared to values of well-watered treatments. However, the reductions were more severe in leaves of diploid clones. Under drought stress, the Seb and Gola, maintained higher E (31.5%), Fv/Fm (6.28%), ψleaf; (11.2%), and RWC (9.3 %) than Q 29 and B 5/4 clones. In general, LT of drought-stressed plants was higher (~4°C) than that of well-watered plants but the relative increase was greater among later than former ones. Under maximum drought stress, LT of Seb and Gola clones was on average 3.0°C lower than that of Q 29 and B 5/4. Former clones yielded 20% more than later ones, mainly reason being (14.8%) less fruit drop as an effect of water stress. The results indicate that presented parameters can be reliable in screening for water stress tolerance ability, with Fv/Fm, ψleaf, RWC and LT having the added advantage of being easily and quickly assessed.

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Osmotic adjustment and its use as a selection criterion in Eucalyptus seedlings

Canadian Journal of Forest Research ◽

10.1139/x94-310 ◽

1994 ◽

Vol 24 (12) ◽

pp. 2404-2408 ◽

Cited By ~ 21

Author(s):

Jorge H. Lemcoff ◽

Ana B. Guarnaschelli ◽

Ana M. Garau ◽

María E. Bascialli ◽

Claudio M. Ghersa

Keyword(s):

Water Stress ◽

Drought Stress ◽

Stress Tolerance ◽

Osmotic Adjustment ◽

Developmental Stages ◽

Selection Criterion ◽

Field Capacity ◽

Water Stress Tolerance ◽

Early Developmental Stages ◽

Early Developmental

Osmotic adjustment was studied in 6-month-old seedlings of Eucalyptuscamaldulensis Dehnh., Eucalyptustereticornis Smith, Eucalyptusviminalis Labill., and Eucalyptusgrandis Hill ex Maiden. Because osmotic adjustment is related to water-stress tolerance, it can be used as a selection criterion of material adapted to drought. Half of the individuals of each species were submitted gradually to water stress, while the rest were maintained in soil at field capacity. Twenty-five days later the effect of stress on the development of osmotic adjustment was analyzed. All species had adjusted osmotically. The lowest osmotic adjustment was observed in E. camaldulensis and E. grandis (14.1% and 15.2%, respectively). Eucalyptusviminalis and E. tereticornis had values of 32.3% and 41.9%, respectively. Our results demonstrate that species differ significantly in their extent of osmotic adjustment under drought stress, and that it is possible to use this inductive plant feature as one of the criteria to select, during early developmental stages, Eucalyptus genotypes adapted to drought-prone environments. Some phylogenetic considerations are presented.

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Genome-Driven Investigation of Compatible Solute Biosynthesis Pathways of Pseudomonas syringae pv. syringae and Their Contribution to Water Stress Tolerance

Applied and Environmental Microbiology ◽

10.1128/aem.00686-10 ◽

2010 ◽

Vol 76 (16) ◽

pp. 5452-5462 ◽

Cited By ~ 32

Author(s):

Matthias Kurz ◽

Adrien Y. Burch ◽

Britta Seip ◽

Steven E. Lindow ◽

Harald Gross

Keyword(s):

Water Stress ◽

Stress Tolerance ◽

Pseudomonas Syringae ◽

Compatible Solutes ◽

Small Contribution ◽

In Planta ◽

Putative Gene ◽

Fusion Strain ◽

Water Stress Tolerance

ABSTRACT The foliar pathogen Pseudomonas syringae pv. syringae exhibits an exceptional ability to survive on asymptomatic plants as an epiphyte. Intermittent wetting events on plants lead to osmotic and matric stresses which must be tolerated for survival as an epiphyte. In this study, we have applied bioinformatic, genetic, and biochemical approaches to address water stress tolerance in P. syringae pv. syringae strain B728a, for which a complete genome sequence is available. P. syringae pv. syringae B728a is able to produce the compatible solutes betaine, ectoine, N-acetylglutaminylglutamine amide (NAGGN), and trehalose. Analysis of osmolyte profiles of P. syringae pv. syringae B728a under a variety of in vitro and in planta conditions reveals that the osmolytes differentially contribute to water stress tolerance in this species and that they interact at the level of transcription to yield a hierarchy of expression. While the interruption of a putative gene cluster coding for NAGGN biosynthesis provided the first experimental evidence of the NAGGN biosynthetic pathway, application of this knockout strain and also a gfp reporter gene fusion strain demonstrated the small contribution of NAGGN to cell survival and desiccation tolerance of P. syringae pv. syringae B728a under in planta conditions. Additionally, detailed investigation of ectC, an orphan of the ectoine cluster (lacking the ectA and ectB homologs), revealed its functionality and that ectoine production could be detected in NaCl-amended cultures of P. syringae pv. syringae B728a to which sterilized leaves of Syringa vulgaris had been added.

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