| Wild soybean（Glycine soja）is an excellent germplasm resource and has strong resistance and wide adaptability to different environments.Therefore,there is a certain application value in the improvement of cultivated soybean varieties and grain production.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,which could be used for reference in the creation of new germplasm resources of cultivated soybean and the continuous production of soybean.In this paper,two ecotypes of wild soybeans（common and salt-tolerant）were cultivated by sandy soil,and they were exposed to two different types of salt stress for14 days.The growth parameters,assimilative function of photosynthesis,ion content and metabolites of two ecotypes of wild soybean were analyzed by gas chromatography-mass spectrometry.The salt tolerance mechanism of wild soybean was revealed by physiological regulation process and the difference of metabolites.The results showed that the growth performance and assimilative function of photosynthesis in salt-tolerant wild soybean was less inhibited than in common wild soybean under neutral-salt stress and alkali-salt stress.Salt-tolerant wild soybean could regulated accumulation of toxic ions and maintained the accumulation of K+and Mg2+to alleviate salt stress.Differential metabolite profiling showed that the salt-tolerant wild accumulated more amino acids and carbohydrates and polyols under neutral-salt salt stress,including serine,alanine,proline,mannitol,and other metabolites,including serine,alanine,proline and mannitol.D-arabinol and inositol.Under alkali-salt stress,more amino acids and organic acids were accumulated in the roots of salt-tolerant wild soybean seedlings.These metabolites included alanine,glycine,phenylalanine,threonine,proline,glutamic acid,asparagine and salicylic acid,gluconic acid and malonic acid.At the same time,the salt-tolerant wild soybean improved tricarboxylic acid metabolisms in response to alkali-salt stress.The study demonstrated that the salt-tolerant wild soybean could resist salt stress by regulating the content of toxic ions and accumulating and maintaining the contents of K+and Mg2+.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.At the same time,the utilization rate of wild soybean germplasm resources was improved,which laid a theoretical foundation for the breeding of new salt-tolerant soybean varieties. |
