Comparative Study On Nutritional Physiology And Multi-Omics Integration Analysis Of Glycine Soja And Glycine Max Seedling Roots Under Low Phosphorus Conditions

Phosphorus（P）is an essential mineral element in plant growth and development,and soil infertile caused by phosphorus deficiency limits the yield and quality of crops.However,excessive application of phosphorus fertilizer in agricultural production can cause a series of problems such as environmental pollution,resource waste,and economic loss,which hinder the sustainable development of agriculture.Therefore,finding low phosphorus tolerance mechanisms in crops and breeding low phosphorus tolerant crops are effective solutions to these problems.Multi-omics correlation analysis techniques are often applied to the study of plant interactions with barren environments and can provide comprehensive and accurate information for studies such as plant responses to abiotic stresses.Wild soybeans are a high quality wild resource with strong resistance to adverse conditions and can be used to improve cultivated soybean resistance to low phosphorus.In this study,we compared the differences in biomass,ion accumulation,gene expression and the types,quantity and metabolic pathways of small molecule metabolites in wild and cultivated soybean seedling roots under phosphorus-sufficient and artificially simulated low-phosphorus conditions,and conducted a multi-omics correlation analysis to uncover the key metabolic pathways,key genes,and key metabolites for low phosphorus tolerance in wild soybean,and to identify sensitive metabolic pathways,sensitive genes,and sensitive metabolites that are susceptible to damage in cultivated soybean,in order to reveal the mechanism of low phosphorus tolerance in wild soybean and the process of low phosphorus damage in cultivated soybean.The main results are as follows:（1）Under low phosphorus stress,the height,aboveground dry weight and fresh weight,and underground dry weight and fresh weight of cultivated soybean seedlings decreased by0.29,1.23,1.35,1.23 and 0.85-fold,respectively,which was significantly greater than that of wild soybean.The root length of wild soybean and cultivated soybean seedlings increased by0.15 and 0.04-fold,respectively.（2）Under low phosphorus stress,the levels of Fe³⁺,Cu²⁺and Zn²⁺were significantly increased by 1.42,0.85 and 1.59-fold in the roots of wild soybean seedlings,respectively,but not significantly changed in roots of cultivated soybean seedlings.（3）Under low phosphorus stress,the expression levels of gene regulating sulfoquin olyltransferase（SQD2）,glutathione S-transferase（GST）,catechol O-methyltransferase（COMT）and peroxidase（POD）were significantly up-regulated in wild soybean seedlin g roots and did not change regularly in cultivated soybean seedling roots.The express ion levels of gene regulating salicylate signalling,S-adenosylmethionine decarboxylase and asparagine synthase were significantly down-regulated in cultivated soybean seedlin g roots and remained stable in wild soybean seedling roots.（4）Under low phosphorus stress,the content of glycerol-3-phosphate related to membrane lipid metabolism in wild soybean and cultivated soybean seedling roots decreased by 1.19 and 0.09-fold,respectively,while the content of glutamic acid,putrescine,phenylalanine,tyrosine,neohesperidin,salicylic acid,and asparagine related to antioxidant and basal nitrogen metabolism significantly increased by 0.43,0.85,1.91,1.67,0.42,0.26,and 2.14-fold,respectively,in wild soybean seedling roots,but decreased by 0.85,0.85,0.52,0.30,0.42,0.15,and 0.97-fold,respectively,in the roots of cultivated soybean seedlings.The above experimental results indicate that wild soybean is more adaptable to low phosphorus.Wild soybean maintains membrane stability by reusing internal phosphorus,promoting membrane lipid remodeling,and scavenging active oxygen species to ensure plant survival under phosphorus deficiency conditions.Salicylic acid signal transduction,antioxidant capacity,and basal nitrogen metabolism in the roots of cultivated soybean seedlings are inhibited,making cultivated soybean unable to maintain normal life activities.This study reveals the key molecular metabolic mechanisms of low phosphorus tolerance in wild soybean and the vulnerable low phosphorus sensitive pathways in cultivated soybean,provides new ideas for studying the mechanisms of phosphorus deficiency tolerance in wild soybean,and lays the theoretical foundation for breeding barren tolerant soybean cultivars.