Integrative analysis of transcriptome and metabolome reveal mechanism of tolerance to salt stress in oat (Avena sativa L.)

Zhongshan Xu; Xiaojing Chen; Xiaoping Lu; Baoping Zhao; Yanming Yang; Jinghui Liu

doi:10.1016/j.plaphy.2021.01.027

Integrative analysis of transcriptome and metabolome reveal mechanism of tolerance to salt stress in oat (Avena sativa L.)

Plant Physiol Biochem. 2021 Mar:160:315-328. doi: 10.1016/j.plaphy.2021.01.027. Epub 2021 Jan 29.

Authors

Zhongshan Xu¹, Xiaojing Chen¹, Xiaoping Lu², Baoping Zhao¹, Yanming Yang¹, Jinghui Liu³

Affiliations

¹ Cereal Industry Collaborative Innovation Center, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, 010019, China; Cereal Engineering Technology Research Center, Inner Mongolia Autonomous Region, Hohhot, Inner Mongolia, 010019, China; National Outstanding Talents in Agricultural Research and Their Innovative Teams, Hohhot, Inner Mongolia, 010019, China.
² Cereal Industry Collaborative Innovation Center, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, 010019, China.
³ Cereal Industry Collaborative Innovation Center, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, 010019, China; Cereal Engineering Technology Research Center, Inner Mongolia Autonomous Region, Hohhot, Inner Mongolia, 010019, China; National Outstanding Talents in Agricultural Research and Their Innovative Teams, Hohhot, Inner Mongolia, 010019, China. Electronic address: cauljh@aliyun.com.

PMID: 33545609
DOI: 10.1016/j.plaphy.2021.01.027

Abstract

Soil salinity is among the crucial factors that impact on crop productivity, including oat (Avena sativa L.). Herein, we used two distinct oat cultivars with varied salt tolerance levels to unravel adaptive responses to salt stress by metabolomic and transcriptomic characterization. Metabolomic profiling revealed 201 metabolites, including saccharides, amino acids, organic acids, and secondary metabolites. The levels of most saccharides and amino acids were elevated in Baiyan 2 (BY2) as well as in Baiyan 5 (BY5) exposed to salt stress. In the tolerant cultivar BY2 exposed to 150 mM NaCl, concentrations of most of the metabolites increased significantly, with sucrose increased by 38.34-fold, Sophorose increased by 314.15-fold and Isomaltose 2 increased by 25.76-fold. In the sensitive cultivar BY5, the concentrations of most metabolites increased after the plant was exposed to 150 mM NaCl but decreased after the plant was exposed to 300 mM NaCl. Transcriptomic analysis revealed that gene expressions in BY5 were significantly affected under exposure to 300 mM NaCl (34040 genes up-regulated and 14757 genes down-regulated). Assessment of metabolic pathways as well as KEGG enrichment revealed that salt stress interferes with the biosynthesis of two oat cultivars, including capacity expenditure and sugar metabolism. Most of the BY2 genes enhanced energy consumption (for example, glycolysis) and biosynthesis (for instance, starch and sugar metabolism) under salt stress. In contrast, genes in BY5 were found to be down-regulated, leading to the inhibition of energy consumption and biosynthesis, which may also be attributed to salt sensitivity in BY5. In addition, the modified Na⁺/K⁺ transporter genes expression is associated with the predominant ionic responses in BY2, which leads low concentration of Na⁺ and high K⁺ when exposed to high salt situations. These findings suggest that the varied defensive capacities of these two oat cultivars in response to salt stress are due to their variations in energy-expenditure strategy, synthesis of energy substances and ion transport in roots. Our present study offers a crucial reference for oat cultivation under saline soil.

Keywords: Metabolome; Oat; Salt stress; Transcriptome.

MeSH terms

Avena* / genetics
Avena* / physiology
Gene Expression Regulation, Plant
Metabolome*
Salinity
Salt Tolerance*
Transcriptome*