Sweetpotato, Ipomoea batatas (L.) Lam., is an important and widely grown crop, yet its production is affected severely by biotic and abiotic stresses. The nucleotide binding site (NBS)-encoding genes have been shown to improve stress tolerance in several plant species. However, the characterization of NBS-encoding genes in sweetpotato is not well-documented to date. In this study, a comprehensive analysis of NBS-encoding genes has been conducted on this species by using bioinformatics and molecular biology methods. A total of 315 NBS-encoding genes were identified, and 260 of them contained all essential conserved domains while 55 genes were truncated. Based on domain architectures, the 260 NBS-encoding genes were grouped into 6 distinct categories. Phylogenetic analysis grouped these genes into 3 classes: TIR, CC (I), and CC (II). Chromosome location analysis revealed that the distribution of NBS-encoding genes in chromosomes was uneven, with a number ranging from 1 to 34. Multiple stress-related regulatory elements were detected in the promoters, and the NBS-encoding genes’ expression profiles under biotic and abiotic stresses were obtained. According to the bioinformatics analysis, 9 genes were selected for RT-qPCR analysis. The results revealed that IbNBS75, IbNBS219, and IbNBS256 respond to stem nematode infection; Ib­NBS240, IbNBS90, and IbNBS80 respond to cold stress, while IbNBS208, IbNBS71, and IbNBS159 respond to 30% PEG treatment. We hope these results will provide new insights into the evolution of NBS-encoding genes in the sweetpotato genome and contribute to the molecular breeding of sweetpotato in the future.
Cytogenet Genome Res

中文翻译：

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甘薯核苷酸结合位点编码基因的表征，Ipomoea batatas(L.) Lam.，及其对生物和非生物胁迫的反应

甘薯、番薯(L.) Lam.，是一种重要且广泛种植的作物，但其生产受到生物和非生物胁迫的严重影响。核苷酸结合位点 (NBS) 编码基因已被证明可以改善几种植物物种的胁迫耐受性。然而，迄今为止，甘薯中 NBS 编码基因的特征还没有得到很好的记录。在这项研究中，利用生物信息学和分子生物学方法对该物种进行了 NBS 编码基因的综合分析。共鉴定出 315 个 NBS 编码基因，其中 260 个包含所有必需的保守结构域，而 55 个基因被截断。基于域架构，260 个 NBS 编码基因被分为 6 个不同的类别。系统发育分析将这些基因分为 3 类：TIR、CC (I) 和 CC (II)。染色体定位分析显示，NBS 编码基因在染色体中分布不均，数量从 1 到 34 不等。获得了非生物胁迫。根据生物信息学分析，选择了9个基因进行RT-qPCR分析。结果表明，IbNBS75、IbNBS219和IbNBS256响应茎线虫感染；IB-NBS240，IbNBS90和IbNBS80响应冷应激，而IbNBS208，IbNBS71和IbNBS159响应至30％PEG治疗。我们希望这些结果能为甘薯基因组中 NBS 编码基因的进化提供新的见解，并为未来甘薯的分子育种做出贡献。
细胞遗传基因组研究