GhCPK28 negatively regulates the immune response by phosphorylating GhTIFY3b

Abstract

AbstractThe soil-borne fungusVerticillium dahliae(V. dahliae) seriously inhibits cotton (Gossypium hirsutum) growth and productivity. The immune system of cotton against this pathogen is largely unknown. Here we investigated the involvement of Ca2+-dependent protein kinases (CPKs) in this immunity. One CPK coding geneGhCPK28had reduced expression after infection byV. dahliaein cotton. Knocking down of theGhCPK28by virus induced gene silencing led to enhanced resistance toV. dahliaewhich is accompanied by a higher ROS accumulation and systemic acquired response. GhCPK28 was found to phosphorylate a TIFY family protein GhTIFY3b and reduce its stability. SilencingGhTIFY3bincreased the susceptibility of cotton toV. dahliae. Together, this study indicate that GhCPK28 is a negative regulator of defense againstV. dahliaeinfection and the GhTIFY3b might be a target protein of its activity. It sheds light on the immune system againstV. dahliaeand provides candidate genes for improving resistance against Verticillium wilt in cotton.