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ABSTRACT: Background
Abiotic stresses (e.g., heat or limited water and nutrient availability) limit crop production worldwide. With the progression of climate change, the severity and variation of these stresses are expected to increase. Exogenous silicon (Si) has shown beneficial effects on plant growth; however, its role in combating the negative effects of heat stress and their underlying molecular dynamics are not fully understood.Results
Exogenous Si significantly mitigated the adverse impact of heat stress by improving tomato plant biomass, photosynthetic pigments, and relative water content. Si induced stress tolerance by decreasing the concentrations of superoxide anions and malondialdehyde, as well as mitigating oxidative stress by increasing the gene expression for antioxidant enzymes (peroxidases, catalases, ascorbate peroxidases, superoxide dismutases, and glutathione reductases) under stress conditions. This was attributed to increased Si uptake in the shoots via the upregulation of low silicon (SlLsi1 and SlLsi2) gene expression under heat stress. Interestingly, Si stimulated the expression and transcript accumulation of heat shock proteins by upregulating heat transcription factors (Hsfs) such as SlHsfA1a-b, SlHsfA2-A3, and SlHsfA7 in tomato plants under heat stress. On the other hand, defense and stress signaling-related endogenous phytohormones (salicylic acid [SA]/abscisic acid [ABA]) exhibited a decrease in their concentration and biosynthesis following Si application. Additionally, the mRNA and gene expression levels for SA (SlR1b1, SlPR-P2, SlICS, and SlPAL) and ABA (SlNCEDI) were downregulated after exposure to stress conditions.Conclusion
Si treatment resulted in greater tolerance to abiotic stress conditions, exhibiting higher plant growth dynamics and molecular physiology by regulating the antioxidant defense system, SA/ABA signaling, and Hsfs during heat stress.
SUBMITTER: Khan A
PROVIDER: S-EPMC7268409 | biostudies-literature | 2020 Jun
REPOSITORIES: biostudies-literature
Khan Adil A Khan Abdul Latif AL Imran Muhammad M Asaf Sajjad S Kim Yoon-Ha YH Bilal Saqib S Numan Muhammad M Al-Harrasi Ahmed A Al-Rawahi Ahmed A Lee In-Jung IJ
BMC plant biology 20200603 1
<h4>Background</h4>Abiotic stresses (e.g., heat or limited water and nutrient availability) limit crop production worldwide. With the progression of climate change, the severity and variation of these stresses are expected to increase. Exogenous silicon (Si) has shown beneficial effects on plant growth; however, its role in combating the negative effects of heat stress and their underlying molecular dynamics are not fully understood.<h4>Results</h4>Exogenous Si significantly mitigated the advers ...[more]