Genome-Wide Analysis of the NF-YB Gene Family in Gossypium hirsutum L. and Characterization of the Role of GhDNF-YB22 in Embryogenesis.

Members of the transcription factor gene family play important roles in diverse processes related to plant growth and development, such as seed development, drought tolerance, and flowering time. However, the function of genes in cotton remains unclear. A total of 23, 24, and 50 genes were identified in (), (), and , respectively. A systematic phylogenetic analysis was carried out in , , , , cacao, rice and, sorghum, where the 150 genes were divided into five groups (α-ε). Of these groups, α is the largest clade, and γ contains the LEC1 type NF-YB proteins. Syntenic analyses revealed that paralogues of genes in exhibited good collinearity. Owing to segmental duplication within the A sub-genome (A) and D sub-genome (D), there was an expanded set of genes in . Furthermore, we investigated the structures of exons, introns, and conserved motifs of genes in upland cotton. Most of the genes had only one exon, and the genes from the same clade exhibited a similar motif pattern. Expression data show that most genes were expressed ubiquitously, and only a few genes were highly expressed in specific tissues, as confirmed by quantitative real-time PCR (qRT-PCR) analysis. The overexpression of gene, predominantly expressed in embryonic tissues, indicates that may affect embryogenesis in cotton. This study is the first comprehensive characterization of the gene family in cotton, and showed that genes could be divided into five clades. The duplication events that occurred over the course of evolution were the major impetus for gene expansion in upland cotton. Collectively, this work provides insight into the evolution of in cotton and further our knowledge of this commercially important species.