Pan-genome Analysis of GT64 Gene Family and Expression Response to Verticillium wilt in Cotton

Abstract

Background The GT64 subfamily, belonging to the glycosyltransferase enzyme family, plays a critical function in plant adaptation to stress conditions and the modulation of plant growth, development, and organogenesis processes. However, a comprehensive identification and systematic analysis of GT64 in cotton are still lacking. Results This study used bioinformatics techniques to conduct a detailed investigation on the GT64 gene family members of eight cotton species for the first time. A total of 39 GT64 genes were detected, which could be classified into five subfamilies according to the phylogenetic tree. Among them, six genes were found in upland cotton. Furthermore, we investigated the precise chromosomal positions of these genes and visually represented their gene structure details. Moreover, we forecasted cis-regulatory elements in GHGT64s and ascertained the duplication type of the GT64 in the eight cotton species. Evaluation of the Ka/Ks ratio for similar gene pairs among the eight cotton species provided insights into the selective pressures acting on these homologous genes. Additionally, we analyzed the expression profiles of the GT64 gene family. Through overexpression of GHGT64_4 in tobacco, overexpression of this gene in tobacco could improve disease resistance of tobacco. Subsequently, VIGS experiments conducted in cotton demonstrated reduced disease resistance upon silencing of the GHGT64_4, suggesting its involvement in affecting lignin and jasmonic acid biosynthesis pathways, thus impacting cotton resistance. Weighted Gene Co-expression Network Analysis (WGCNA) revealed an early immune response against Verticillium dahliae in G. barbadense compared to G. hirsutum. qRT-PCR analysis indicated that some GT64 genes might play a role under various biotic and abiotic stress conditions. Subcellular localization results showed that GHGT64_4 is mainly located in the endoplasmic reticulum and Golgi apparatus. Conclusions These discoveries enhance our knowledge of GT64 family members and lay the groundwork for future investigations into the disease resistance mechanisms of this gene in cotton.