Genome-wide identification and expression analysis of the UPF0016 family in tomato (Solanum lycopersicum) under drought stress

As bivalent cation transporters, UPF0016 family is widely expressed in eukatyotes. UPF0016 family has been shown to regulate plants growth, development and photosynthesis. However, studies of UPF0016 family have not been reported in tomato (Solanum lycopersicum L.), and the biological function of this family is still unclear. In this study, we performed the first comprehensive genome-wide characterization and expression in the UPF0016 family in tomato with 5 UPF0016 family members being identified, named as SlPML1, SlPML2, SlPML3, SlPML4 and SlPML5, which were regulated in a tissue-specific manner. Based on phylogenetic analysis, 5 SlPMLs could be divided into 3 groups, with the character of their chromosome distribution, gene structure and conserved protein motifs of 5 SlPMLs were characterized. RT-qPCR analysis indicated that SlPML may aid regulation of tomato in response to abiotic stress. Among these 5 members, SlPML3 was selected and utilized for further experiments, which might be localized in endomembrane compartments. It was found that SlPML3 could relieve membrane lipid peroxidation and reduce the damage of photosynthesis under drought stress, and further efforts need to be explored on its regulatory mechanism. Thus, this study provides an overview of the UPF0016 family in tomato and lays on valuable resource for further analysis on their function and regulatory mechanisms.