Endoplasmic Reticulum Subproteome Analysis Reveals Underlying Defense Mechanisms of Wheat Seedling Leaves under Salt Stress

Abstract

Salt stress is the second most important abiotic stress factor in the world, which seriously affects crop growth, development and grain production. In this study, we performed the first integrated physiological and endoplasmic reticulum (ER) proteome analysis of wheat seedling leaves under salt stress using a label-free-based quantitative proteomic approach. Salt stress caused significant decrease in seedling height, root length, relative water content and chlorophyll content of wheat seedling leaves, indicating that wheat seedling growth was significantly inhibited under salt stress. The ER proteome analysis identified 233 ER-localized differentially accumulated proteins (DAPs) in response to salt stress, including 202 upregulated and 31 downregulated proteins. The upregulated proteins were mainly involved in the oxidation-reduction process, transmembrane transport, the carboxylic acid metabolic process, stress response, the arbohydrate metabolic process and proteolysis, while the downregulated proteins mainly participated in the metabolic process, biological regulation and the cellular process. In particular, salt stress induced significant upregulation of protein disulfide isomerase-like proteins and heat shock proteins and significant downregulation of ribosomal protein abundance. Further transcript expression analysis revealed that half of the detected DAP genes showed a consistent pattern with their protein levels under salt stress. A putative metabolic pathway of ER subproteome of wheat seedling leaves in response to salt stress was proposed, which reveals the potential roles of wheat ER proteome in salt stress response and defense.

An Extremely Streamlined Macronuclear Genome in the Free-Living Protozoan Fabrea salina

“…These findings mirror the results of previous studies, which showed that G protein receptors play an important role in the response to abiotic stresses, especially high salinity ( Liu et al 2018 ). Activation of chaperones and folding catalysts is a key way for organisms to deal with misfolded proteins resulting from the accumulation of reactive oxygen species owing to salt stress ( Zhang et al 2021 ). Next, we found that the most significant changed DEGs were enriched in the genes specific to the high salinity group (Fisher’s exact test, P = 1.4 × 10 −7 ), rather than those shared with the low salinity group ( fig.…”

Label-Free Quantitative Proteome Analysis Reveals the Underlying Mechanisms of Grain Nuclear Proteins Involved in Wheat Water-Deficit Response

“…The grain nuclear proteome identification was performed by using EASY-nLC 1000 (Thermo/Finnigan, Sanjose, CA, United States) according to the recent report ( Zhang et al, 2021 ).…”

“…Various protein post-translational modifications also participate in regulating drought responses such as phosphorylation and acetylation modifications ( Zhang et al, 2014a , b ; Zhu et al, 2018 ). In recent years, subcellular proteomics has been developed to decipher different organelle proteins involved in abiotic stress defense such as endoplasmic reticulum, plasma membrane, chloroplast, and mitochondria ( Wang and Komatsu, 2016 ; Zhang et al, 2021 ; Zhu et al, 2021 ).…”

Responses of Endoplasmic Reticulum to Plant Stress

“…Although many studies have reported the role of ER stress signalling in salt stress response, the underlying molecular mechanism and client proteins for the ER-associated regulatory mechanisms are still unknown. Zhang et al [95] performed the first ER proteome analysis of wheat seedlings to understand the role of ER proteostasis pathways in salt-induced growth reduction. They proposed a putative mechanism whereby salt stress generates ROS, which triggers Redox reactions in the cell leading to the accumulation of misfolded proteins.…”