The Verticillium dahliae Effector VdPHB1 Promotes Pathogenicity in Cotton and Interacts with the Immune Protein GhMC4.

This article focuses on the identification and functional characterization of VdPHB1, a prohibitin effector protein secreted by the pathogenic fungus Verticillium dahliae, which causes wilt disease in cotton. VdPHB1 is highly expressed during infection and localizes to the intercellular space of cotton plants, where it interacts with the cotton type II metacaspase GhMC4, a cysteine protease involved in programmed cell death and immune responses. Knockout of VdPHB1 in V. dahliae reduces fungal virulence without affecting growth, while ectopic expression of VdPHB1 in Arabidopsis inhibits growth and increases susceptibility to infection. Silencing GhMC4 in cotton decreases resistance to V. dahliae, and VdPHB1 suppresses GhMC4 protein accumulation and reactive oxygen species production, revealing a molecular mechanism by which VdPHB1 represses cotton immunity to facilitate pathogen infection.