Metabolomics and its physiological regulation process reveal the salt-tolerant mechanism in Glycine soja seedling roots

Wild soybean (Glycine soja) is an excellent germplasm resource and has strong resistance and wide adaptability to different environments. Hence, the physiology and metabolomics characteristics of wild soybean under different types of salt stress were determined to improve understanding of salt-tolerant mechanisms of wild soybean in the field. Two types of wild soybean seedlings were exposed to two different types of salt stress for 14 d. The photosynthesis of wild soybean seedling extracts were analyzed using metabolomics based on gas chromatography-mass spectrometry. The wild soybean root extracts used metabolomics to quantify the metabolic changes and ion contents. The assimilative function of photosynthesis in salt-tolerant wild soybean was less inhibited than in common wild soybean, and it regulated accumulation of toxic ions and maintained the accumulation of K+ and Mg2+ to alleviate salt stress. Moreover, in resisting salt stress the salt-tolerant wild soybean has showed improved amino acid and carbohydrate and polyol metabolisms under neutral-salt stress and organic acid, amino acid and tricarboxylic acid metabolisms under alkali-salt stress. Our results provide valuable insights into the response of salt-tolerant wild soybean to two types of salt stress by linking stress-related physiological responses to changes in metabolites.