Regulation of phytosterol biosynthetic pathway during drought stress in rice

• Published in: Plant physiology and biochemistry Vol. 129; pp. 11 - 20
• Main Authors: Kumar, M.S. Sujith, Mawlong, Ibandalin, Ali, Kishwar, Tyagi, Aruna
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.08.2018
• Subjects: Abscisic Acid - metabolism; Chromatography, High Pressure Liquid; Dehydration; Drought tolerance; HMG-CoA reductase; Hydroxymethylglutaryl CoA Reductases - metabolism; Metabolic Networks and Pathways; Oryza - metabolism; Oryza - physiology; Phospholipid sterol acyltransferase; Phytosterols - biosynthesis; Phytosterols - metabolism; Phytosterols - physiology; Plant Growth Regulators - metabolism; Rice; Water - metabolism; ABA; RP-HPLC; HMGR; MSI; SE; PSAT; HMG-CoA reductase; Drought tolerance; Phospholipid sterol acyltransferase; Rice; RWC
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2018.05.019

Plants respond to drought stress in the form of various physio-biochemical and molecular changes at both cellular and molecular levels. Drought stress causes the destruction of cell membranes by disintegration of membrane lipids. One of the major groups of membrane lipids that plays important role in preserving the integrity of cell membranes is phytosterols. HMG-CoA reductase (HMGR) is the principal enzyme in the biosynthesis of plant sterols, synthesized via mevalonic acid pathway. Phospholipid: sterol acyltransferase (PSAT) is another important enzyme that plays an important role in turnover of phytosterols into steryl esters and helps maintain homeostasis of membrane lipids. In this study, the expression of both HMGR and PSAT genes in drought sensitive (IR64) and drought tolerant (N22) rice cultivars under applied drought conditions were found to be elevated. The increase in expression of these genes was proportional to the level of severity of applied drought stress. This is substantiated by the negative correlation of HMGR and PSAT expression to relative water content (RWC) and membrane stability index (MSI). Expression of PSAT was also found to be positively correlated to ABA content and HMGR expression. •Effect of drought stress on sterol content and other biochemical parameters in two contrasting cultivars of rice was analyzed.•Phospholipid: sterol acyltransferase (PSAT) gene was isolated in rice.•Gene expression of HMGR and PSAT during drought stress was studied using realtime PCR.