Appraising diverse metrics of nitric oxide in salt stress tolerance of high yielding wheat genotypes

Abstract

Staple crop vulnerability has been escalating with significant approach due to climatic variations leading to persistent salt accumulation as inimical environmental stressors, and thus endangering food security. To address this global concern, there is a need to elucidate the growth, physiological and yield responses, entailing plant salt tolerance modifications. Recent years have been advocated with studies focusing on the integration of nitric oxide (NO), however there is a need of critical decipherment on NO synthesis is regulated under salt stress conditions. With this focus, the present investigation has assessed the salt-mediated differential impacts on the plant growth, root architecture, photosynthetic pigment, carbon metabolites (carbohydrate and starch), and stomatal frequency, leading to restrained plant metabolisms in the 49 wheat genotypes. Further, the accumulation of secondary metabolites (flavonoids and phenols) was found concomitant with the improved NO biosynthesis in salt-stressed tolerant wheat genotype. To validate the involvement of endogenous NO as salt stress tolerance criterion, use of NO scavenger (cPTIO) suggests the involvement of NO in enhancing salt tolerance and stress defense metabolites mainly lignin biosynthesis, and cellulose to attain plant stress tolerance. These underlying interactions could pave the way to convey wheat tolerance for the future breeding programs.