Genome-wide identification and expression analysis of the MADS-box transcription factor family in Camellia sinensis

The MADS-box genes are an important class of transcription factors and play critical roles in flower development. However, the functions of these genes in the economically important drinking plant, Camellia sinensis, are still not reported. Here, an evolutionary analysis of tea MADS-box genes was performed at whole genome level. A total of 83 MADS-box genes were identified in tea, and their gene structures and expression patterns were further analyzed. The tea MADS-box genes were classified into Mα (26), Mβ (12), Mγ (9), MIKC* (7), and MIKCC (29) clade according to their phylogenetic relationship with Arabidopsis thaliana. Several cis-elements were identified in the promoter regions of the CsMADS genes that are important in regulating growth, development, light responses, and the response to several stresses. Most CsMADS genes display clear different expression patterns in different organs and different species of tea plant. The expression of CsMADS genes can be regulated by abiotic stresses and phytohormone treatment. Our results lay the foundation for future research on the function of CsMADS genes and beneficial for improving tea agricultural traits in the future.