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