Journal of Peanut Science

In this study,physiological index determination and liquid chromatography-tandem mass spectrometry(LC-MS/MS) analysis methods were utilized to explore the primary water absorption patterns and the variation characteristics of differential metabolites in peanut seeds during germination under salt stress.Peanut seeds absorb water rapidly during germination,however,both the total water uptake and the absorption rate were significantly decreased after being inhibited by salt stress.The difference in the total water uptake between the salt treatment and the control was the greatest at 72 h,reaching21.71 %,and the rate of water absorption in the salt treatment group decreased the most at 3 h, by 11.58%.Principal component analysis and partial least squares discriminant analysis showed a distinct separation of metabolites between the salt-stressed group and the control group,indicating that salt stress exerts a significant impact on metabolism during peanut seed germination.VIP value analysis and KEGG pathway prediction revealed that L-glutamic acid was the most active differential metabolite,followed by L-glutamine,L-aspartic acid,and glucose-1-phosphate.These metabolites are primarily involved in diverse metabolic processes such as amino acid metabolism,carbon-nitrogen metabolism,lipid metabolism,and glucose metabolism.Additionally,key stress-responsive metabolic pathways,including secondary metabolite biosynthesis,flavonoid biosynthesis,purine metabolism,and ABC transporter pathways,exhibited significant enrichment of differential metabolites,which may play a vital role in peanut seed germination under salt stress.In summary,during the early germination stage under salt stress,peanut seeds may enhance their salt tolerance by activating metabolic pathways such as secondary metabolite biosynthesis,purine metabolism,and ABC transporter pathways,thereby adapting to external salt stress.Among these,L-glutamic acid is likely to act as a key regulatory factor enabling peanut seeds to adapt to salt stress during germination.