Genome-wide analysis of amino acid transporter genes reveals their potential roles in drought stress and drought-associated disease responses in peanut (Arachis hypogaea)
Amino acid transporters (AATs) are central to nitrogen allocation, amino acid distribution, and metabolic adjustment in plants, but this gene family has not been systematically characterized in cultivated peanut (Arachis hypogaea). In this study, 30 AAT genes were identified from the peanut genome and analyzed for chromosomal distribution, protein properties, gene structure, phylogenetic relationships, and expression profiles. The identified ArahyAAT genes were unevenly distributed across 18 chromosomes and showed marked variation in exon-intron organization, which indicates structural diversification within the family. Transcriptome analysis revealed different expression patterns across vegetative and reproductive tissues, with several genes showing preferential expression in roots, nodules, and reproductive organs. To assess their stress responsiveness, five root low-expression genes were selected for RT-qPCR analysis under drought stress and combined drought stress plus charcoal rot infection. ArahyAAT04, ArahyAAT09, and ArahyAAT21 were induced under drought stress, while ArahyAAT07 showed strong induction under the combined treatment. ArahyAAT23 showed limited transcriptional change across the tested conditions. These results suggest that specific ArahyAAT genes may contribute to stress-associated amino acid transport and metabolic adjustment in peanut roots. This study provides a genome-wide characterization and expression analysis of the peanut AAT gene family and identifies candidate genes for future functional studies on...