Genome-wide identification of the phospholipase gene family in Panax notoginseng and functional analysis of PnPLA1-8 response to Fusarium oxysporum infection

Panax notoginseng is highly susceptible to root rot during cultivation, severely affecting its production and quality. Phospholipases participate in plant immunity by producing free fatty acids and conjugated lipids that activate downstream signaling cascades. However, genome-wide identification of PnPL genes in P. notoginseng remains limited. A total of 72 PnPL genes were identified in P. notoginseng: 48 PnPLA genes, 9 PnPLC genes and 15 PnPLD genes. Transcriptome and qRT-PCR analyses between healthy and diseased plants (CK, RⅠ and RⅡ) revealed 13 differentially expressed genes from PnPL Gene Family, 11 of which belonged to the PnPLA genes superfamily. Notably, PnPLA1-8 exhibited sustained upregulation with worsening root rot. Further, RNA interference (RNAi) mediated silencing of PnPLA1-8 gene increased susceptibility to Fusarium oxysporum that the main pathogenic fungus in P. notoginseng, whereas overexpression of PnPLA1-8 gene in Nicotiana tabacum enhanced resistance to F. oxysporum. This study suggests that the PnPLA1-8 genes exhibit potential roles in resistance to F. oxysporum.