GhSTZ-Mediated Suppression of Metabolic-Immune Coordination Compromises Cotton Defense Against Verticillium Wilt

Verticillium wilt (VW), caused by Verticillium dahliae, poses a significant threat to global cotton production. Through analysis of public transcriptome databases, this study identified GhSTZ, a C2H2 zinc finger protein transcription factor gene, which was significantly induced by V. dahliae. Suppressing GhSTZ expression via virus-induced gene silencing significantly enhanced cotton resistance to VW. This resistance manifested as a 1.2-fold increase in lignin deposition, optimized ROS (reactive oxygen species) homeostasis, and a 1.3-fold elevation in glucose levels. Transcriptome analysis revealed 338 differentially expressed genes in GhSTZ-silenced plants, with 97 upregulated and 241 downregulated. Key downregulated genes included PME (pectin methylesterase) and PG1-pec (polygalacturonase) in the pentose phosphate pathway, while the key upregulated genes comprised C4H (cinnamate 4-hydroxylase) and C3H (p-coumarate 3-hydroxylase) in the phenylpropanoid biosynthesis pathway. Notably, in the plant-pathogen interaction signaling pathway, approximately half of the genes exhibited upregulated expression while the other half showed downregulation. Protein-protein interaction network analysis further revealed cooperative interaction between PME and the secoisolariciresinol dehydrogenase SIRD. This study is the first to elucidate GhSTZ as a negative regulator that compromises cotton disease resistance through a tripartite mechanism. These findings offer a novel approach to enhancing crop disease resistance by targeting the negative regulatory genes.