Comparative Proteome Analysis of the Penultimate Internodes of Barley Genotypes Differing in Stem Reserve Remobilization Under Drought Stress

Abstract

Barley yield relies more on stem reserves under stress conditions at the grain filling stage. At terminal drought stresses, the remobilization of reserved assimilates from stem to seed contributes a major role in yield. To understand the molecular mechanism of stem reserve utilization during drought stress, a comparative proteome and physiological analyses were performed on the penultimate internodes of three genotypes of barley Yousef (tolerant), Morocco (susceptible), and PBYT17 (semi-tolerant) under drought stress at 21 and 28 days after anthesis (DAA). Under water stress and well-watered conditions Yousef showed significantly higher RWC, grain yield, and stem reserve remobilization capacity than susceptible and semi-tolerant genotypes. The proteome analysis led to the identification of 1580 differentially abundant proteins (DAPs), of which 759 and 821 proteins were differentially expressed at 21 and 28 DAA, respectively. Tolerant genotype in response to drought stress increased the abundance of several plant cell wall polysaccharide degradation proteins and protein kinases associated with posttranslational-associated, which might accelerate remobilization process for seed biomass formation compared to susceptible one under drought stress. However, the susceptible genotype increased the abundance of proteins involved in RNA metabolism and transcriptional changes to save energy sources for the growth and survival during drought stress. These findings suggest that barley might response to water stress by efficiently remobilize assimilates from stem to grain through specific remobilization processes.

A comprehensive meta-QTL analysis for yield-related traits of durum wheat (Triticum turgidum L. var. durum) grown under different water regimes

“…Another detected important gene on chromosome 2A was endo-1,4-beta-xylanase 1-like, involved in the hydrolyzation of the xylan backbones into shorter and soluble xylo-oligo saccharides. The xylanase is strongly expressed in tolerant barley genotype under drought stress for the mobilization of the nutrients from the aleurone layer and endosperm to the developing seed ( Hajibarat et al, 2022 ). Among the gene models detected, different disease resistance protein RGA were identified and specifically RGA3 , and RGA4 (two different), and RGA5 on chromosomes 5A, 5B, and 7B under both irrigated and rainfed condition.…”