Genome-Wide Analysis of Genes and Their Expression Profiling during Fiber Development in Cotton.

Amino acid transporters () are a kind of membrane proteins that mediate the transport of amino acids across cell membranes in higher plants. The AAT proteins are involved in regulating plant cell growth and various developmental processes. However, the biological function of this gene family in cotton fiber development is not clear. In this study, 190, 190, 101, and 94 full-length genes were identified from , , , and . A total of 575 genes from the four cotton species were divided into two subfamilies and 12 clades based on phylogenetic analysis. The genes in the four cotton species were distributed on all the chromosomes. All genes contain multiple exons, and each GhAAT protein has multiple conserved motifs. Transcriptional profiling and RT qPCR analysis showed that four genes tend to express specifically at the fiber initiation stage. Eight genes tend to express specifically at the fiber elongation and maturity stage, and four genes tend to express specifically at the fiber initiation and elongation stages. Our results provide a solid basis for further elucidating the biological function of genes related to cotton fiber development and offer valuable genetic resources for crop improvement in the future.