Cotton ethylene response factor GhERF91 involved in the defense against Verticillium dahliae

Verticillium dahliae causes significant losses in cotton production. To uncover the mechanism of the defense response to Verticillium dahliae in cotton, transcriptomic analyses of cotton cultivars M138 (Verticillium dahliae-resistant) and P2 (Verticillium dahliae-susceptible) were performed. The results revealed 11,076 and 6,640 differentially expressed genes in response to Verticillium dahliae, respectively. The weighted gene co-expression network analysis of 4,633 transcription factors (TFs) indicated a "MEblue" module containing 654 TFs that strongly correlate with the resistance to Verticillium dahliae. Among these TFs, the ethylene response factor Ghi_A05G10166 (GhERF91) was identified as a putative hub gene with a defense response against Verticillium dahliae. A virus-induced gene silencing assay and exogenous application of ethephon showed that GhERF91 was activated by ethylene and positively regulated the response to Verticillium dahliae in cotton. This study provides fundamental transcriptome data and a putative causal gene GhERF91 associated with the resistance to Verticillium dahliae as well as genetic resources for breeding Verticillium dahliae-resistant cotton.