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 StTCP7 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 StTCP7 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 StTCP7 transcription factor could bind the promoter region of StDAM5 and StGOLS2 and regulate the expression of their genes. qRT-PCR analysis showed that the expression level of StDAM5 gene was the highest in flower stalk tissue and the lowest in leaf stalk. The expression of StGOLS2 gene was the highest in stem, the second in stalk, and the lower in root. Both StDAM5 and StGOLS2 genes responded to abiotic stress treated with 200 mM NaCl, 20% PEG-6000 and 100 µM ABA. The expression levels of target genes StDAM5 and StGOLS2 were up-regulated in StTCP7 interfered plants. The protein encoded by the target gene StDAM5 belongs to the Type II MADS-box protein, which contains 238 amino acids and is an acidic hydrophilic protein. The analysis of StDAM5 promoter region showed that the promoter region of StDAM5 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.