Morpho-physiological Responses of Rice to Salicylic Acid under Drought Stress

Abstract

Salicylic acid (SA) is vital in controlling plant growth and development. Water deficiency is acute environmental stress to field crops causing low production of crops. Rice is one of the staple crops whose yields and quality are highly affected due to drought stress. Despite the importance of SA in crop production, little information has been reported concerning the effect of SA under drought
stress. Therefore, the possible physiological and morphological responses of rice to SA were investigated under drought conditions. In this study, the external application of 2-hydroxybenzoic acid (Salicylic acid) was identified as a positive tool in decreasing the stress of the drought effect. The field experiment was arranged under a randomized complete block design (RCBD) containing three replications of SA and drought stress treatments. The SA treatments consisted of 0, 250, 500, 750 and 1000 µMm-2 concentrations and drought stresses were slight, moderate and severe. Following the treatments, higher leaf number, leaf area index, relative water content, leaf membrane stability index and pigment content were determined for the application of 750 µMm-2 of SA compared to the
alternative treatments and management of plants. Exogenous application of SA during drought stress has growth-promoting and stress priming effects on rice plants, hence reducing yield limitation. The findings of the study imply that SA can be utilized as a protective agent to increase water use efficiency, osmotic management, and pigment content to reduce the negative effects of
drought stress on rice growth and physiology, resulting in optimum yield.