Effects of two amino acid transporter-like genes on potato growth

Amino acid transporters are membrane proteins that mediate amino acid transport across the plasma membrane. They play a significant role in plant growth and development. The amino acid permease (AAP) subfamily belongs to the activating transcription factor family, which is one of the main amino acid transporter families. Potato AAP genes were identified through simple bioinformatics, and the functions of StAAP1 and StAAP8 were verified by plant subcellular localization and potato transgenic technology. In this study, eight AAP-like genes in potato were separated into two subgroups based on the differences in the number of pore-lining residues. To identify the locations where the genes were expressed, we built green fluorescent protein expression vectors for two genes, StAAP1 and StAAP8, and found that these two genes were expressed on the plasma membrane. Meanwhile, we constructed overexpression vectors for these two genes to construct transgenic plants. By observing the phenotype of the transgenic plants, we concluded that StAAP1 and StAAP8 promoted leaf growth and increased leaf area and StAAP1 elongated the potato tubers. Overall, these two genes did not significantly affect tuber weight or number. However, the assessment of amino acid content in potato tubers showed that StAAP8 overexpression increased the content of amino acids, and some of these amino acids were related to protein synthesis. Therefore, StAAP8 overexpression may promote the accumulation of plant amino acids. Studies have shown that there are some differences in the functions of different transcription factor members. The studied AAP8 gene plays a role in amino acid transport and protein accumulation in potato tubers, which provides support for subsequent research on potato tuber nutrition.