Elicitor-Induced Biochemical and Molecular Manifestations to Improve Drought Tolerance in Rice (Oryza sativa L.) through Seed-Priming

Abstract

Rice (Oryza sativa L.) is one of the major grain cereals of the Indian subcontinent which face water-deficit stress for their cultivation. Seed-priming has been reported to be a useful approach to complement stress responses in plants. In the present study, seed-priming with hormonal or chemical elicitor [viz. methyl jasmonate (MJ), salicylic acid (SA), paclobutrazol (PB)] showed significant increase in total phenolic content, antioxidant activity and expression of Rice Drought-responsive (RD1 and RD2) genes (of AP2/ERF family) in contrasting rice genotypes (Nagina-22, drought-tolerant and Pusa Sugandh-5, drought-sensitive) under drought stress. However, decrease in lipid peroxidation and protein oxidation was observed not only under the stress but also under control condition in the plants raised from primed seeds. Expression analyses of RD1 and RD2 genes showed upregulated expression in the plants raised from primed seeds under drought stress. Moreover, the RD2 gene and the drought-sensitive genotype showed better response than that of the RD1 gene and the drought-tolerant genotype in combating the effects of drought stress. Among the elicitors, MJ was found to be the most effective for seed-priming, followed by PB and SA. Growth and development of the plants raised from primed seeds were found to be better under control and drought stress conditions compared to that of the plants raised from unprimed seeds under the stress. The present study suggests that seed-priming could be one of the useful approaches to be explored toward the development of simple, cost-effective and farmer-friendly technology to enhance rice yield in rainfed areas.

Epigenomics of Plant Responses to Environmental Stress

“…Insights into the molecular conservation of stress memory in crop species are scarce. However, like chemical priming of seeds to enhance stress tolerance of young plants, referred to as seed-priming [115], understanding the mechanisms of stress priming/memory might enable manipulation for tailored responses of crop plants to respond more efficiently to the challenges presented by the climate change. Thus, there is great potential for generation of environment-mediated heritable epigenetic variations, which actually drive/influence the evolution process in living organisms.…”

Role of Biotic Elicitors as Potent Inducer of Defence Mechanism against Salt-Stress in Wheat (Triticum aestivum L.)

“…Also, seedpriming with selenium (Se) and SA was found to be effective in protecting rice plants against chilling stress [8]. Recently, bio-elicitorinduced biochemical and molecular manifestations to improve drought tolerance in rice [9] and impact of seed priming on proline content and antioxidant enzymes to mitigate drought stress in rice have been already reported [10].…”

Drought Tolerance and Evaluation of Genetic Changes in Rice Mutant Lines

“…Mutant lines indicated tolerance to drought in a selection processes, it should be showing relationship between phenotype and genotype. Based on reports from QTL and molecular data showed that a key gene has immediate response to drought and other biotic stressed Samota et al, 2017;Borah et al, 2017;Prince et al, 2015). The plant's phenotype showed tolerance to drought can be observed such as panicle length and fertile grains, roots length.…”