谷子NBS-LRR类基因家族全基因组鉴定及表达分析

Genome-Wide Identification and Expression Analysis of NBS-LRR Gene Family in Setaria italica

对谷子NBS-LRR类家族成员进行鉴定,并对其染色体分布、基因结构、保守基序、系统进化及表达水平进行分析,为NBS-LRR类家族基因在谷子抗病分子育种中的应用奠定基础。结果表明,共获得NBS-LRR类家族基因411个,其中含CN(CC-NBS)结构的基因376个,含CNL(CC-NBS-LRR)结构的基因33个,含TIR(Toll interleukin-1 receptor)结构的基因1个,仅含NBS结构的基因1个。多数NBS-LRR类家族基因定位在8号染色体。在谷子中NBS结构域存在4段保守序列,且该家族在系统进化中被分为3类,基因结构多样,保守基序Motif1结构最保守。有23个谷子NBS-LRR类基因与狗尾草存在共线性,21个与水稻存在共线性,仅1个与拟南芥存在共线性,其中Seita.8G088500和Seita.8G088400被鉴定为水稻抗稻瘟病的高度同源基因。谷子与水稻、拟南芥的共线性基因的Ka/Ks值均小于1;与狗尾草的共线性基因中,Seita.6G014500、Seita.6G023500的Ka/Ks值均大于1。表达谱分析表明,在谷子根和穗中高表达的NBS-LRR类基因数目较多,叶次之,幼芽中最少,表明该家族基因可能在根及穗抗病过程中发挥重要作用。

The NBS-LRR family members of foxtail millet(Setaria italica)were identified,and their chromosome location,gene structure,conserved motif,phylogeny and expression level were analyzed,which laid a foundation for the application of NBS-LRR family genes in molecular breeding of disease resistance in Setaria italica.The results showed that 411 genes of NBS-LRR family were obtained,including 376 genes with CN(CC-NBS)structure,33 genes with CNL(CC-NBS-LRR)structure,1 gene with TIR(Toll interleukin-1 receptor)structure,and only 1 gene with NBS structure.Most of the NBS-LRR family genes were located on chromosome 8.There were four conserved sequences in the NBS domain of Setaria italica,and the family was divided into three groups in phylogeny.The gene structure was diverse,and Motif1 was the most conserved.Twenty-three NBS-LRR genes of Setaria italica were collinear with those of Setaria viridis,21 NBS-LRR genes of Setaria italica were collinear with those of Oryza sativa,1 NBS-LRR gene of Setaria italica was collinear with those of Arabidopsis thaliana.Among them,Seita.8G088500 and Seita.8G088400 were identified as high homologous genes to rice blast resistance genes.The Ka/Ks values of collinear genes between Setaria italica and Oryza sativa,Arabidopsis thaliana were less than 1,but among the collinear genes between Setaria italica and Setaria viridis,Ka/Ks values of Seita.6G014500 and Seita.6G023500 were greater than 1.Expression profile analysis showed that the number of NBS-LRR genes highly expressed in the roots and panicles of foxtail millet was more,followed by the leaves,and the least in the shoots,indicating that the family genes may play an important role in the process of disease resistance in the roots and panicles.