Genome-wide identification, characterization and expression analysis of the DUF668 gene family in tomato.

The domain of unknown function 668 (DUF668) is a gene family that may play a key role in plant growth and development as well as in responding to adversity coercion stresses. However, the DUF668 gene family has not yet been well identified and characterized in tomato. In this study, a total of nine putative genes were identified in tomato, distributed on six chromosomes. Phylogenetic analyses revealed that SlDUF668 proteins were classified into two major groups. Members within the same group largely displayed analogous gene structure and conserved motif compositions. Several -elements were exhibited in the upstream sequences of the genes, including elements implicated in plant growth and development processes, abiotic stress and hormone responses. Further, the study assessed the expression patterns of the SlDUF668 gene family in various tomato tissues, five plant hormones treatments, three abiotic stresses using qRT-PCR. The genes expressed ubiquitously in various tissues, and five genes (, , , and ) showed tissue specificity. And genes responded to abiotic stresses such as salt, drought and cold to varying degrees. Overall, our study provided a base for the tomato DUF668 gene family and laid a foundation for further understanding the functional characteristics of genes in tomato plants.