ABSTRACT Saline–alkali stress is a major factor limiting oat growth in various parts of the world. Amino acids, which are essential structural and metabolic compounds in plants, play a crucial role in enhancing salt tolerance. During abiotic stress, amino acids such as proline, arginine and asparagine are synthesised to serve as compatible osmotic regulators, precursors for secondary metabolites, or organic nitrogen storage compounds. In this study, we examined the effect of salt–alkali stress on amino acid metabolism in two oat varieties. Transcriptomic, proteomic and metabolomic analyses were performed to identify amino acid metabolism‐related genes, proteins and metabolites in salt‐sensitive and salt‐tolerant oats after 6, 12, 24 and 48 h of saline–alkali stress. Saline–alkali stress significantly affected five groups of amino acids: oxaloacetate, glycerate, aromatic, pyruvate and α‐ketoglutarate. Among the amino acids identified, phenylalanine and tyrosine showed relatively high expression levels at the transcriptome, proteome and metabolome levels. Genes related to amino acids, including cysK , SHMT , PAL and TDC (amino acid content regulators), were differentially expressed between the two oat varieties and amino acid metabolites such as L‐glutamate, L‐asparagine, L‐aspartic acid, glutathione and betaine were differentially regulated. Key genes, including ASNS , serA , PRODH and cysK , were significantly differentially expressed in both varieties under stress, as validated by RT‐qPCR. This study provides a comprehensive analysis of amino acid metabolism in two oat varieties with different salt tolerances and offers insights into the regulatory mechanisms of amino acid metabolism under abiotic stress.
Ling et al. (Fri,) studied this question.