Genome-wide identification of SINA gene family in Medicago truncatula and functional analysis of MtSINAL7.

Ubiquitination is an essential biological process that is vital for maintaining cellular activity and plays a critical role in precisely regulating protein levels within cells. The SINA (seven in absentia) protein belongs to the RING-type E3 ubiquitin ligase, which is one of the key enzymes involved in the process of ubiquitination. However, there have been few reports on the genome-wide identification of SINA gene family and the functional analysis of its specific genes, particularly in leguminous plants. In this study, a total of 20 MtSINA genes were identified from the genomes of Medicago truncatula, and classified into three subfamilies. These genes are distributed on 7 of 8 chromosomes with chromosome preference. The gene structures of most MtSINA genes are quite similar, and all MtSINA proteins contain conserved RING and SINA functional domains. Moreover, various cis-regulatory elements related to abiotic stress and hormone signals were found in the promoters of MtSINA genes. The expression profile indicates that a majority of MtSINA genes exhibit a significant response to abiotic stress. Furthermore, the study characterized the function of MtSINAL7 in plants and discovered its pivotal role in improving plant stress resistance. In summary, this study provides a new insight into the potential functions of MtSINA genes in Medicago truncatula.