Lipid Metabolomic and Transcriptomic Analyses Reveal That Phosphatidylcholine Enhanced the Resistance of Peach Seedlings to Salt Stress through Phosphatidic Acid.

Soil salinity is a major conlinet limiting sustainable agricultural development in peach tree industry. In this study, lipid metabolomic pathway analysis indicated that phosphatidic acid is essential for root resistance to salt stress in peach seedlings. Through functional annotation analysis of differentially expressed genes in transcriptomics, we found that MAPK signaling pathway is closely related to peach tree resistance to salt stress, wherein expression is significantly upregulated. Under salt conditions, the OE- (L.) Heynh. line showed higher resistance to salt stress than WT and KO- lines. Furthermore, we found that the Na content in OE- roots was significantly lower than that in WT and KO- roots, indicating that phosphatidic acid combined with activated the SOS1 (salt-overly-sensitive 1) protein to enhance Na efflux, thus alleviating the damage caused by NaCl in roots; these findings provide insight into the salt stress-associated transcriptional regulation.