Overexpression of a Cytosolic Abiotic Stress Responsive Universal Stress Protein (SbUSP) Mitigates Salt and Osmotic Stress in Transgenic Tobacco Plants

Abstract

The universal stress protein (USP) is a ubiquitous protein and plays an indispensable role in plant abiotic stress tolerance. The genome of Salicornia brachiata contains two homologs of intron less SbUSP gene which encodes for salt and osmotic responsive USP. In vivo localization reveals that SbUSP is a membrane bound cytosolic protein. The role of the gene was functionally validated by developing transgenic tobacco and compared with control [wild-type (WT) and vector control (VC)] plants under different abiotic stress condition. Transgenic lines (T1) exhibited higher chlorophyll, relative water, proline, total sugar, reducing sugar, free amino acids, polyphenol contents, osmotic potential, membrane stability, and lower electrolyte leakage and lipid peroxidation (malondialdehyde content) under stress treatments than control (WT and VC) plants. Lower accumulation of H2O2 and O2− radicals was also detected in transgenic lines compared to control plants under stress conditions. Present study confers that overexpression of the SbUSP gene enhances plant growth, alleviates ROS buildup, maintains ion homeostasis and improves the physiological status of the plant under salt and osmotic stresses. Principal component analysis exhibited a statistical distinction of plant response to salinity stress, and a significant response was observed for transgenic lines under stress, which provides stress endurance to the plant. A possible signaling role is proposed that some downstream genes may get activated by abiotic stress responsive cytosolic SbUSP, which leads to the protection of cell from oxidative damages. The study unveils that ectopic expression of the gene mitigates salt or osmotic stress by scavenging ROS and modulating the physiological process of the plant.

Metabolic profiling and scavenging activities of developing circumscissile fruit of psyllium (Plantago ovata Forssk.) reveal variation in primary and secondary metabolites

“…Total lipid composition was statistically analysed by principal component analysis (PCA) and a heat map was generated. Lipid data set was used to generate Pearson's correlation matrix, and PCA along with respective heat map was inferred [55,61] using different software including Sigma Plot (ver. 12), SYSTAT (ver.…”

Gene expression differs in codominant prairie grasses under drought

“…More gene‐groups showed greater sensitivity within Sorghastrum , however. Of these, one was linked to osmotic stress (SALT_ORYSJ), three with general stress (USPAL_ARATH, NSUS4_ARATH and TIL_ARATH), two with ABA response (CUT1B_ARATH and GRPA_MAIZE) and only one with oxidative stress (MSRB1_ORYSJ) (Abo‐Ogiala et al., ; Alvarez, Roy Choudhury, & Pandey, ; Dinakar, Vishwakarma, Raghavendra, & Padmasree, ; Kline, Barrett‐Wilt, & Sussman, ; Liu et al., ; Roy & Nandi, ; Udawat, Jha, Sinha, Mishra, & Jha, ; Zhang, Zhao, Xiao, Zheng, & Yue, ). The more sensitive response by these gene‐groups in Sorghastrum could indicate greater stress response by this species, especially for gene‐groups related to water management.…”

The Promoter of AtUSP Is Co-regulated by Phytohormones and Abiotic Stresses in Arabidopsis thaliana

“…Expression of several plant USP genes has been shown to be induced under various abiotic stresses, but their precise molecular function is still unknown (Sauter et al, 2002; Maqbool et al, 2009; Loukehaich et al, 2012; Gonzali et al, 2015; Jung et al, 2015; Sinha et al, 2016; Udawat et al, 2016). Two plant USPs, i.e., SpUSP from wild tomato and SbUSP from S. brachiata have been reported to be induced in response to multiple abiotic stresses (Loukehaich et al, 2012; Udawat et al, 2014).…”

“…Kerk et al (2003) identified 44 genes encoding USPA domain containing proteins in Arabidopsis and performed their phylogenetic analysis which revealed that they have evolved from 1MJH like ancestor. Since then, several USP proteins have been reported to play important roles in stress tolerance in various plants, such as Arabidopsis , rice, cotton, tomato, pigeonpea, and Salicornia brachiata (Sauter et al, 2002; Lenman et al, 2008; Merkouropoulos et al, 2008; Maqbool et al, 2009; Loukehaich et al, 2012; Udawat et al, 2014, 2016; Gonzali et al, 2015; Jung et al, 2015; Sinha et al, 2016). However, the precise function of most of the plant USPs has not been deciphered, so far.…”