Genome-Wide Characterization of the ZIP Transporter Family in Sea Island Cotton (Gossypium barbadense L.) and Expression Profiling Under Heavy Metal and Pathogen Stresses
Simple Summary Sea Island cotton (Gossypium barbadense L.) is widely cultivated for its high-grade extra-long staple fiber and excellent disease resistance. However, its cultivation is increasingly threatened by soil heavy metal contamination (such as cadmium toxicity) and fungal diseases (such as Verticillium wilt caused by Verticillium dahliae). Zinc/iron-regulated transporter-like proteins (ZIPs) serve as essential membrane transporters that manage transition metal homeostasis and modulate stress responses in plants. In this study, we systematically identified 46 GbZIP genes across the G. barbadense genome and comprehensively evaluated their structural characteristics, evolutionary origin, cis-regulatory elements, and expression patterns. Transcriptional analysis demonstrated that several key GbZIP members dynamically respond to cadmium exposure, fungal infection, and their combined occurrence. These findings highlight crucial candidate genes for molecular breeding aimed at improving stress resilience and metal tolerance in premium cotton germplasm.