Abstract
The domain of the unknown function 221 proteins regulate several processes in plants, including development, growth, hormone transduction mechanism, and abiotic stress response. Therefore, a comprehensive analysis of the potato genome was conducted to identify the deafness-dystonia peptide (DDP) proteins’ role in potatoes. In the present study, we performed a genome-wide analysis of the potato domain of the unknown function 221 (DUF221) genes, including phylogenetic inferences, chromosomal locations, gene duplications, gene structures, and expression analysis. In our results, we identified 10
DDP
genes in the potato genome. The phylogenetic analysis results indicated that
StDDPs
genes were distributed in all four clades, and clade IV was the largest clade. The gene duplication under selection pressure analysis indicated various positive and purifying selections in
StDDP
genes. The putative stu-miRNAs from different families targeting
StDDPs
were also predicted in the present study. Promoter regions of
StDDP
genes contain different
cis
-acting components involved in multiple stress responses, such as phytohormones and abiotic stress-responsive factors. The analysis of the tissue-specific expression profiling indicated the
StDDPs
gene expression in stem, root, and leaf tissues. We subsequently observed that
StDDP4
,
StDDP5
,
and StDDP8
showed higher expressions in roots, stems, and leaves.
StDDP5
exhibited high expression against heat stress response, and
StDDP7
showed high transcript abundance against salt stress in potatoes. Under abscisic acid (ABA) and indole acetic acid (IAA) treatments, seven
StDDP
genes’ expressions indicated that ABA and IAA performed important roles in immunity response. The expression profiling and real-time qPCR of stems, roots, and leaves revealed
StDDPs’
significant role in growth and development. These expression results of
DDPs
are primary functional analysis and present basic information for other economically important crops.