Plant Phosphatidylinositol Signalling Network in Cotton Resistance to Verticillium Wilt

Verticillium wilt, a devastating vascular disease in cotton, threatens global production. This review delineates how the conserved phosphatidylinositol (PI) signalling pathway forms a regulatory network conferring resistance against this pathogen. We detail how core enzymes-notably GhPIP5K9a and GhPLDδ-catalyse the production of lipid second messengers, PI(4,5)P₂ and phosphatidic acid, which collectively orchestrate a multidimensional defence network. This network directs membrane microdomain reorganisation for pathogen recognition, activates specific Mitogen-Activated Protein Kinase (MAPK) cascades to regulate defensive transcription factors, and integrates with calcium and hormone signalling to coordinate stomatal closure, lignin deposition, and reactive oxygen species homoeostasis. By critically comparing findings from model plants like Arabidopsis, we highlight unique or divergent regulatory nodes in cotton, such as the crosstalk between the PI signalling and specific MAPK modules and the role of cotton-specific regulators in linking lipid signals to hormone pathways. Recent breakthroughs in phosphoproteomics and single-cell sequencing are unravelling this spatiotemporally complex circuit.