Genome-Wide Identification, Characterization and Evolution of BBX Gene Family in Cotton

Background: The B-BOX (BBX) proteins have important functions in the regulation of photomorphogenesis. The BBX gene family has been identified in several plants, such as rice, Arabidopsis and tomato. However, there still lack a genome-wide survey of BBX genes in cotton. Results: In our present study, 63 GhBBX genes were identified in cotton. The analyses of phylogenetic evolution and gene structure showed that the GhBBX genes were divided into five subfamilies, and contained B-box conserved domains. qRT-PCR analysis releaved that both GhBBX27 and GhBBX33 had potential roles in proanthocyanidin synthesis of brown cotton fibers. Conclusions: This study provides a genome-wide survey of the BBX gene family in cotton and highlights its role in proanthocyanidin synthesis. This result will help us to further understand the complexity of the BBX gene family and the functional characteristics of its members.