Role of osmoprotectants and drought tolerance in wheat

In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from abiotic stresses. Spm has been shown to protect plants from a variety of environmental insults, but whether it can prevent the adverse effects of drought has not yet been reported. Drought stress increases endogenous Spm in plants and exogenous application of Spm improves the plants’ ability to tolerate drought stress. Spm’s role in enhancing antioxidant defense mechanisms, glyoxalase systems, methylglyoxal (MG) detoxification, and creating tolerance for drought-induced oxidative stress is well documented in plants. However, the influences of enzyme activity and osmoregulation on Spm biosynthesis and metabolism are variable. Spm interacts with other molecules like nitric oxide (NO) and phytohormones such as abscisic acid, salicylic acid, brassinosteroids, and ethylene, to coordinate the reactions necessary for developing drought tolerance. This review focuses on the role of Spm in plants under severe drought stress. We have proposed models to explain how Spm interacts with existing defense mechanisms in plants to improve drought tolerance.

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Corrigendum: Physiological and Proteomic Analysis of the Rice Mutant cpm2 Suggests a Negative Regulatory Role of Jasmonic Acid in Drought Tolerance

Frontiers in Plant Science ◽

10.3389/fpls.2018.00465 ◽

2018 ◽

Vol 9 ◽

Author(s):

Rohit Dhakarey ◽

Manish L. Raorane ◽

Achim Treumann ◽

Preshobha K. Peethambaran ◽

Rachel R. Schendel ◽

...

Keyword(s):

Drought Tolerance ◽

Jasmonic Acid ◽

Proteomic Analysis ◽

Regulatory Role ◽

Rice Mutant ◽

Negative Regulatory Role

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Innovative Role of DH Breeding in Genomics Assisted-Crop Improvement: Focus on Drought Tolerance in Wheat

Genomics Assisted Breeding of Crops for Abiotic Stress Tolerance, Vol. II - Sustainable Development and Biodiversity ◽

10.1007/978-3-319-99573-1_5 ◽

2019 ◽

pp. 69-90

Author(s):

H. K. Chaudhary ◽

A. Badiyal ◽

W. Hussain ◽

N. S. Jamwal ◽

N. Kumar ◽

...

Keyword(s):

Drought Tolerance ◽

Crop Improvement

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Exopolysaccharides Producing Bacteria for the Amelioration of Drought Stress in Wheat

Sustainability ◽

10.3390/su12218876 ◽

2020 ◽

Vol 12 (21) ◽

pp. 8876

Author(s):

Noshin Ilyas ◽

Komal Mumtaz ◽

Nosheen Akhtar ◽

Humaira Yasmin ◽

R. Z. Sayyed ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Drought Stress ◽

Drought Tolerance ◽

Indole Acetic Acid ◽

Stress Hormones ◽

Carotenoid Content ◽

Bacterial Strains ◽

Morphological Attributes ◽

Vigor Index

This research was designed to elucidate the role of exopolysaccharides (EPS) producing bacterial strains for the amelioration of drought stress in wheat. Bacterial strains were isolated from a farmer’s field in the arid region of Pakistan. Out of 24 isolated stains, two bacterial strains, Bacillus subtilis (Accession No. MT742976) and Azospirillum brasilense (Accession No. MT742977) were selected, based on their ability to produce EPS and withstand drought stress. Both bacterial strains produced a good amount of EPS and osmolytes and exhibited drought tolerance individually, however, a combination of these strains produced higher amounts of EPS (sugar 6976 µg/g, 731.5 µg/g protein, and 1.1 mg/g uronic acid) and osmolytes (proline 4.4 µg/mg and sugar 79 µg/mg) and significantly changed the level of stress-induced phytohormones (61%, 49% and 30% decrease in Indole Acetic Acid (IAA), Gibberellic Acid (GA), and Cytokinin (CK)) respectively under stress, but an increase of 27.3% in Abscisic acid (ABA) concentration was observed. When inoculated, the combination of these strains improved seed germination, seedling vigor index, and promptness index by 18.2%, 23.7%, and 61.5% respectively under osmotic stress (20% polyethylene glycol, PEG6000). They also promoted plant growth in a pot experiment with an increase of 42.9%, 29.8%, and 33.7% in shoot length, root length, and leaf area, respectively. Physiological attributes of plants were also improved by bacterial inoculation showing an increase of 39.8%, 61.5%, and 45% in chlorophyll a, chlorophyll b, and carotenoid content respectively, as compared to control. Inoculations of bacterial strains also increased the production of osmolytes such asproline, amino acid, sugar, and protein by 30%, 23%, 68%, and 21.7% respectively. Co-inoculation of these strains enhanced the production of antioxidant enzymes such as superoxide dismutase (SOD) by 35.1%, catalase (CAT) by 77.4%, and peroxidase (POD) by 40.7%. Findings of the present research demonstrated that EPS, osmolyte, stress hormones, and antioxidant enzyme-producing bacterial strains impart drought tolerance in wheat and improve its growth, morphological attributes, physiological parameters, osmolytes production, and increase antioxidant enzymes.

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Incredible Role of Osmotic Adjustment in Grain Yield Sustainability under Water Scarcity Conditions in Wheat (Triticum aestivum L.)

Plants ◽

10.3390/plants9091208 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1208

Author(s):

Tahir Mahmood ◽

Muhammad Abdullah ◽

Sunny Ahmar ◽

Muhammad Yasir ◽

Muhammad Shahid Iqbal ◽

...

Keyword(s):

Drought Tolerance ◽

Osmotic Adjustment ◽

Yield Components ◽

Positive Association ◽

Kernel Weight ◽

Environment Interaction ◽

Plant Yield ◽

Wheat Genotypes ◽

Yield Sustainability

Interrogations of local germplasm and landraces can offer a foundation and genetic basis for drought tolerance in wheat. Potential of drought tolerance in a panel of 30 wheat genotypes including varieties, local landraces, and wild crosses were explored under drought stress (DS) and well-watered (WW) conditions. Considerable variation for an osmotic adjustment (OA) and yield components, coupled with genotype and environment interaction was observed, which indicates the differential potential of wheat genotypes under both conditions. Reduction in yield per plant (YP), thousand kernel weight (TKW), and induction of OA was detected. Correlation analysis revealed a strong positive association of YP with directly contributing yield components under both environments, indicating the impotence of these traits as a selection-criteria for the screening of drought-tolerant genotypes for drylands worldwide. Subsequently, the association of OA with TKW which contributes directly to YP, indicates that wheat attains OA to extract more water from the soil under low water-potential. Genotypes including WC-4, WC-8 and LLR-29 showed more TKW under both conditions, among them; LLR-29 also has maximum OA and batter yield comparatively. Result provides insight into the role of OA in plant yield sustainability under DS. In this study, we figure out the concept of OA and its incredible role in sustainable plant yield in wheat.

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