Genome-wide identification and analysis of DEAD-box RNA helicases in Gossypium hirsutum

[Display omitted] •146 GhDEAD-box genes were identified, which were highly conserved with AtDEADs.•GhDEADs share similar evolutionary relationships, and most of which expanded through segmental duplication.•Clade C of GhDEADs shared higher and ubiquitously expression patterns in different tissues.•Some of GhDEADs were induced or inhibited by drought.•GhDEADs were up-regulated in the leaves of VIGS-GhVIR plants and were related to leaf morphogenesis. DEAD-box RNA helicases, a prominent subfamily within the RNA helicase superfamily 2 (SF2), play crucial roles in the growth, development, and abiotic stress responses of plants. This study identifies 146 DEAD-box RNA helicase genes (GhDEADs) and categorizes them into four Clades (Clade A-D) through phylogenetic analysis. Promoter analysis reveals cis-acting elements linked to plant responses to light, methyl jasmonate (MeJA), abscisic acid (ABA), low temperature, and drought. RNA-seq data demonstrate that Clade C GhDEADs exhibit elevated and ubiquitous expression across different tissues, validating their connection to leaf development through real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Notably, over half of GhDEADs display up-regulation in the leaves of virus-induced gene silencing (VIGS) plants of GhVIR-A/D (members of m6A methyltransferase complex, which regulate leaf morphogenesis). In conclusion, this study offers a comprehensive insight into GhDEADs, emphasizing their potential involvement in leaf development.