Genome-wide identification of F-box-LRR gene family and the functional analysis of CsFBXL13 transcription factor in tea plants

This study focused on the identification and functional analysis of the F-box-LRR (FBXL) protein family in tea tree (Camellia sinensis), aiming to reveal its role in spring bud germination and environmental adaptation. Thirty-seven members of the tea tree F-box-LRR gene family were identified and systematically analyzed for their chromosomal localization, gene structure, conserved motifs, and cis-acting elements by bioinformatics methods. It was found that these genes were distributed on 14 chromosomes, with strong conserved and inter-gene covariance characteristics. Cis-acting element analysis showed that the F-box-LRR family members were associated with signals such as low temperature, gibberellin and growth hormone, which may play a key role in spring low-temperature germination. In addition, the study verified that the CsWRKY40 transcription factor directly binds to the promoter region of the CsFBXL13 gene and significantly activates its expression by subcellular localization, yeast one-hybridization and dual luciferase assays, revealing the important function of the CsWRKY40-CsFBXL13 regulatory axis in low-temperature response and spring bud germination in tea tree. This study not only expands the understanding of the F-box-LRR protein family, but also provides potential molecular targets for improving the resistance and productivity of tea tree through molecular breeding.