Screening and Identification of Target Gene of StTCP7 Transcription Factor in Potato

TCP transcription factors are involved in the regulation of plant growth and development and response to stress. Previous studies showed that <i>StTCP7</i> was involved in the abiotic stress response of potato and positively regulated plant tolerance to drought stress. On the basis of previous studies, this study verified the downstream target genes of <i>StTCP7</i> transcription factor binding through yeast one hybridization, double luciferase and other technologies, and conducted a preliminary analysis of the downstream target genes. The results showed that the <i>StTCP7</i> transcription factor could bind the promoter region of <i>StDAM5</i> and <i>StGOLS2</i> and regulate the expression of their genes. qRT-PCR analysis showed that the expression level of <i>StDAM5</i> gene was the highest in flower stalk tissue and the lowest in leaf stalk. The expression of <i>StGOLS2</i> gene was the highest in stem, the second in stalk, and the lower in root. Both <i>StDAM5</i> and <i>StGOLS2</i> genes responded to abiotic stress treated with 200 mM NaCl, 20% PEG-6000 and 100 µM ABA. The expression levels of target genes <i>StDAM5</i> and <i>StGOLS2</i> were up-regulated in <i>StTCP7</i> interfered plants. The protein encoded by the target gene <i>StDAM5</i> belongs to the Type II MADS-box protein, which contains 238 amino acids and is an acidic hydrophilic protein. The analysis of <i>StDAM5</i> promoter region showed that the promoter region of <i>StDAM5</i> gene contained cis-acting elements such as light response and abscisic acid. Subcellular localization showed that StDAM5 protein was expressed in both nucleus and cytoplasm.