关键词: 芝麻, SiNPF, 渍害胁迫, 生物信息学分析, 表达分析

Abstract: The nitrate transporter 1/peptide transporter family（NRT1/PTR family，NPF）plays a crucial role in nitrogen uptake and utilization in plants，and is also involved in diverse biotic and abiotic stress responses.To elucidate the function of NPF in the waterlogging stress of sesame（Sesamum indicum L.），a systematic bioinformatics analysis was conducted to identify SiNPF genes. Furthermore，the dynamic expression profiles of selected SiNPFs under submergence conditions were characterized.The results of genome⁃wide analysis indicated that a total of 66 SiNPF members were identified in sesame，distributed across 12 chromosomes（excluding chr13），with chr2（12 genes），chr6（11），chr8（9），and chr9（8）being gene⁃enriched regions.And after constructing the phylogenetic tree（Mega 7，NJ method），it was found that these genes were divided into 10 subfamilies.The analysis of gene structure and conserved motif revealed that the majority of SiNPFs had similar gene structures and high conservation，with 44 SiNPFs containing all conserved motifs.Protein property analysis indicated that SiNPF proteins ranged in molecular weight from 20.96 to 135.01 ku，with the majority being alkaline（48 proteins）and stable（52），all of which were hydrophobic（GRAVY>0）.Transmembrane topology prediction（TMHMM）showed that these proteins contained multiple transmembrane domains（4 to 17）.The prediction results of the cis acting elements of the promoters showed a high frequency of cis⁃acting elements，including light⁃responsive elements，and ABA⁃responsive，anaerobically induced，and methyl jasmonate⁃responsive elements.Transcriptome analysis revealed that under waterlogging stress，15 SiNPFs were significantly downregulated in the roots of sesame varieties C177 and C185，while SiNPF2，SiNPF48，and SiNPF56 were significantly upregulated.The results of cloning and sequencing of these three significantly upregulated SiNPFs from varieties C177 and C185 showed that the amino acid sequence differences between the two varieties were limited，and the overall similarity was high. RT⁃qPCR validation confirmed that the expression patterns of these three genes under waterlogging stress were highly consistent with the transcriptome sequencing results.These findings indicate that specific SiNPF genes are closely associated with waterlogging response in sesame，providing a theoretical basis for further investigation on the biological functions of SiNPF genes and breeding of new waterlogging⁃tolerant sesame varieties.

Key words: Sesame, SiNPF, Waterlogging stress, Bioinformatics analysis, Expression analysis