Comprehensive Lipidomic and Transcriptomic Analysis of Arabidopsis upon Verticillium dahliae Infection

Lipids play a crucial role in the initiation and establishment of plant defense responses, however, the mechanisms underlying the links between lipid dynamics and downstream transcriptional events against pathogens remain largely unclear. Here, we conducted a lipidomic analysis to investigate the lipid profile of Arabidopsis seedlings in response to Verticillium dahliae. Our results revealed that V. dahliae infection triggered profound lipid metabolism and transcriptional reprogramming in Arabidopsis. Comprehensive profiling showed extensive remodeling of lipid-associated metabolic pathways, characterized by the significant accumulation of lysophospholipids (LysoPLs) in infected seedlings. This lipid perturbation was mechanistically linked to the transcriptional activation of phospholipase A (PLA) coding genes such as PLA2A, PLA-Iβ2 and PLP5. Genetic evidence has demonstrated that these PLAs are required for disease resistance because their loss-of-function mutants exhibit incresed susceptibility to V. dahliae and compromise the expression of defense-related genes. Furthermore, the PLAs acted as the central regulatory nodes in modulating multiple defense-related signal axes, including SA, JA and ROS, as well as differentially regulating the expression of defense-related genes in response to LysoPLs signal. Together, these findings uncovered an integrated lipid-based and transcription regulatory network, wherein PLA-mediated LysoPLs dynamics served as a critical determinant of plant immunity against V. dahliae.