Executive Summary : | In fields, rice plants are exposed to a combination of biotic and abiotic stresses. Such exposure can disrupt the metabolism of plants and lead to yield loss. Rice is a major crop of our country. So, the loss in yield can directly affect the life of majority of people. However, in nature we observe that some of the rice varieties do survive under such a stressful condition and produce good yields. This shows that rice plants are equipped with necessary molecular mechanisms to defend complex environmental stresses. The present proposal is aimed to study these defence responses from rice and identify the key components involved. Biotic and abiotic stresses when present simultaneously in plants can interact with each other and may influence the effect of damages differently than the individual stresses. It is a well known fact that abscisic acid (ABA), a sesquiterpene is one of the major regulatory hormones in plants for abiotic stress adjustment. On the other hand, another plant hormone jasmonic acid (JA) can efficiently manage the detrimental effect of biotic stress specially caused by necrotrophic pathogens. Therefore, it is in demand to explore broadly the crosstalk between JA and ABA to understand the interaction between biotic and abiotic stresses and to uncover the genes and molecular mechanisms involved. To address this question a suitable rice (Oryza sativa L.) variety will be selected from a number of available varieties like Swarna, IR64, Nona Bokra differing in their disease susceptibilities and yield [Aich et al., 2019; Muthusamy et al., 2020]. For instance, a high yielding rice variety like IR64 can be one of the candidates. For our experiments 15-day-old seedlings will be collected in four groups after germination. The 1st, 2nd and 3rd group will be primed with suitable solution either supplemented with desired concentrations of JA or ABA or with both for 24 h, respectively. On the other hand, the 4th group (without priming with either JA or ABA) will be considered as control. Thereafter, one set of each group of seedlings will be subjected to combined biotic (by Rhizoctonia solani) and abiotic (by NaCl) stresses for 48 h and the other set of each group will remain without any stress. Thereafter, sampling will be done and the seedlings will be used for analysis of several morphological, biochemical and molecular attributes with appropriate statistical analysis to fulfil the objectives. This study will provide the insights on how the two types of hormones interact with each other and their efficacy to manage the damages caused by the combined biotic and abiotic stresses. Furthermore, the study will help to analyse the interconnections among different attributes under two different types of stresses at a time in rice plants with their correlations.
References: 1. Aich, A.R. et al. 2019. Journal of Pharmacognosy and Phytochemistry, 8(4), 2479-2482 2. Muthusamy, S.K. et al. 2019. Applied biochemistry and biotechnology, 187, 221-238 |