Data from: Identification and distribution of the NBS-LRR gene family in the Cassava genome

Background: Plant resistance genes (R genes) exist in large families and usually contain both a nucleotide-binding site domain and a leucine-rich repeat domain, denoted NBS-LRR. The genome sequence of cassava (Manihot esculenta) is a valuable resource for analysing the genomic organization of resistance genes in this crop. Results: With searches for Pfam domains and manual curation of the cassava gene annotations, we identified 228 NBS-LRR type genes and 99 partial NBS genes. These represent almost 1% of the total predicted genes and show high sequence similarity to proteins from other plant species. Furthermore, 34 contained an N-terminal toll/interleukin (TIR)-like domain, and 128 contained an N-terminal coiled-coil (CC) domain. 63% of the 327 R genes occurred in 39 clusters on the chromosomes. These clusters are mostly homogeneous, containing NBS-LRRs derived from a recent common ancestor. Conclusions: This study provides insight into the evolution of NBS-LRR genes in the cassava genome; the phylogenetic and mapping information may aid efforts to further characterize the function of these predicted R genes.

背景：植物抗病基因（R genes）多以大家族形式存在，通常同时包含核苷酸结合位点结构域（nucleotide-binding site domain）与富含亮氨酸重复结构域（leucine-rich repeat domain），该类结构域组合被简称为NBS-LRR。木薯（Manihot esculenta）的基因组序列是解析该作物抗病基因基因组组织的宝贵资源。结果：通过Pfam结构域检索以及木薯基因注释的人工整理与校正，本研究共鉴定得到228个NBS-LRR型基因与99个部分NBS基因。上述基因约占预测总基因数的1%，且与其他植物物种的蛋白质序列具有较高相似度。此外，其中34个基因包含N端Toll/白细胞介素（TIR）样结构域，128个基因包含N端卷曲螺旋（CC）结构域。327个R基因中有63%分布于染色体上的39个基因簇中，这些基因簇大多具有同质性，其内的NBS-LRR基因均源自近期共同祖先。结论：本研究为木薯基因组中NBS-LRR基因的进化研究提供了新视角；其系统发育分析与基因定位信息，将助力后续进一步解析这些预测R基因的功能。