Metabolic Differences Between Suaeda Salsa and Puccinellia Tenuiflora Under Saline-alkali Stress

Background: Salinization of soil is an urgent problem that restricts agroforestry production and environment protection. Substantial accumulation of metal ion or high alkaline alters plant metabolites and may even cause plant death. In order to explore the differences in the response strategies between Suaeda salsa (S. salsa) and Puccinellia tenuiflora (P. tenuiflora), two main constructive species that survive in saline-alkali soil, their metabolic differences were characterized.Result: Metabolomics was conducted to study the role of metabolic differences between S. salsa and P. tenuiflora under saline-alkali stress. A total of 68 significantly different metabolites were identified by GC-MS, including 9 sugars, 13 amino acids, 8 alcohols, and 34 acids. A more detailed analysis indicated that P. tenuiflora utilizes sugars more effectively and may be salt-alkali tolerant via sugar consumption while S. salsa mainly utilizes amino acids, alcohols, and acids to resist salt-alkali stress. Measurement of phenolic compounds showed that more C6C3C6-compounds were accumulated in P. tenuiflora while more C6C1-compounds, phenolic compounds that can be used to defense stress as signaling molecules, were accumulated in S. salsa.Conclusion: Our observations suggest that S. salsa resists the toxicity of saline-alkali stress using aboveground organs and P. tenuiflora eliminates the poison of saline-alkali via roots. S. salsa has a stronger ability of habitat transformation and can provide better habitat for other plants.