Analysis of Trihelix Genes and Their Expression in Potato in Response to Abiotic Stresses

Trihelix genes have important roles in light response, growth/developmental stages, and environmental stresses. The aims of this study were to identify and characterize trihelix genes in potato in response to abiotic stresses via an in silico genome-wide analysis approach and validation of gene expression using qRT-PCR. To investigate the functions of trihelix genes, conserved motifs, duplication patterns, phylogenetic tree, and expression of 22 trihelix transcription factors in potato were analysed under abiotic stresses (heat, cold, and high light). Further, a synteny analysis was performed to identify paralogues of trihelix in the potato genome. The phylogenetic tree of trihelix genes was grouped into five clusters based on their domain homology. According to the synteny analysis, trihelix genes of potato revealed high similarity (90%) between StTH38 and StTH41 and between StTH14 and StTH05 genes. Prediction of cis-elements showed that NF-YB, NF-YA, NF-YC, bHLH, MYB, WRKY, and G-box had maximum frequency in the promoter region of trihelix genes. In general, various cis-elements including abiotic, hormone-responsive, light-responsive, and defence-responsive elements were found in trihelix promoter sequences. At 24 h after stress, StTH41 and StTH31 genes showed low expression in all tissues. The StTH41 gene under high light stress showed a relatively high expression in the root. At 48 h after stress, the StTH41 and StTH31 genes showed high expression in root and leaf tissues under all stress treatments. Under all stress treatments, the StTH43 gene showed high expression at 24 h but was down-regulated at 48 h. This is the first study to evaluate the role of trihelix genes in potato in response to abiotic stresses. Our findings could be considered as a useful source for future comparative and molecular mechanisms of trihelix gene studies among different plant species. In conclusion, our findings showed that some trihelix genes can play important roles during abiotic stresses in potato.