GauCNL18 mediates Verticillium wilt resistance by activating the salicylic acid immunity pathway

Verticillium wilt (VW) is caused by Verticillium dahliae and significantly impacts cotton yield and quality. Breeding of resistant varieties is the most effective strategy for controlling VW. Therefore, it is important to identify VW resistance genes. The diploid wild cotton species Gossypium australe is highly resistant to VW. This study identified 33 CC-NBS-LRR (CNL) genes in the G. australe genome. GauCNL expression pattern (EP) analyses showed that EP1 cluster which included four of the 33 genes, were significantly up-regulated after V. dahliae inoculation. The EP1 cluster genes were then introduced into Arabidopsis thaliana wild type Col-0, respectively. The results showed GauCNL18 overexpression significantly increased V. dahliae resistance, indicating the functional importance of GauCNL18. GauCNL18 promotes V. dahliae resistance by activating the salicylic acid signaling pathway to mediate up-regulating pathogenesis-related genes and reactive oxygen species accumulation. This study identified a CNL resistance gene, GauCNL18, and revealed its resistance mechanism to V. dahliae.