Genome-Wide Analysis of BURP Domain-Containing Gene Family in Solanum lycopersicum and Functional Analysis of SlRD1 Under Drought and Salt Stresses

The BURP domain-containing (BURP) genes belong to plant-specific families and are known as essential for various biological processes in plants. However, knowledge of the functions of BURP genes in tomato (Solanum lycopersicum) is lacking. In our study, bioinformatics analysis was performed for the SlBURP gene family, including phylogeny, chromosomal localization, gene structure, cis-acting elements and expression. In addition, the function of SlRD1 in drought and salt stresses was explored. In tomato, fourteen BURP family members were identified, located on five chromosomes, including two tandem duplication clusters. These BURP members were classified into four subfamilies. The promoter regions of SlBURPs harbored numerous hormone- and stress-response elements. Tissue expression analysis showed that several SlBURPs were highly expressed in roots, flowers or fruits. Meanwhile, the expressions of most SlBURPs could be regulated by drought, salt and cold treatments, and some of them also responded to ABA treatment. Moreover, the ectopic expression of SlRD1 in Arabidopsis enhanced tolerances to drought and salt stresses and increased the sensitivity of seed germination to ABA. In conclusion, the comprehensive analysis of the SlBURP family in tomato and the functional exploration of SlRD1 in drought and salt stresses provide a basis for further dissecting the roles of tomato BURP genes.