Homologues of a single resistance-gene cluster in potato confer resistance to distinct pathogens: a virus and a nematode
Homologues of a single resistance-gene cluster in potato confer resistance to distinct pathogens: a virus and a nematode
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DOI：
10.1046/j.1365-313x.2000.00814.x
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发表时间：
2000-09-01
期刊：
影响因子：
7.2
通讯作者：
Klein-Lankhorst, RM
中科院分区：
文献类型：
--
作者：
van der Vossen, EAG;van der Voort, JNAMR;Klein-Lankhorst, RM
本文介绍了马铃薯抗线虫基因Gpa 2的分离，证明了同一个抗病基因簇中高度同源的抗病基因可以赋予马铃薯对不同病原菌的抗性。Gpa 2基因座的分子分析导致在一个约115 kb的区域中的四个高度同源的基因的R-基因簇的鉴定。这些基因中至少有两个是有活性的：一个对应于先前分离的Rx 1基因，赋予对马铃薯X病毒的抗性，而另一个对应于Gpa 2基因，赋予对马铃薯孢囊线虫Globodera pallida的抗性。Gpa 2和Rx 1基因编码的蛋白质具有88%以上的同源性（氨基酸同源性），属于含亮氨酸拉链、核苷酸结合位点、富含亮氨酸重复序列（LZ-NBS-LRR）的植物抗性基因。从Gpa 2和Rx 1之间的序列保守性可以清楚地看出，这两种蛋白质之间存在直接的进化关系。序列多样性集中在LRR区域和C-末端。推定的效应结构域是更保守的，这表明，至少在这种情况下，线虫和病毒抗性级联可以共享共同的组件。这些发现强调了蛋白质育种在体外工程新的抗植物病原体特异性方面的潜力。
The isolation of the nematode-resistance gene Gpa2 in potato is described, and it is demonstrated that highly homologous resistance genes of a single resistance-gene cluster can confer resistance to distinct pathogen species. Molecular analysis of the Gpa2 locus resulted in the identification of an R-gene cluster of four highly homologous genes in a region of approximately 115 kb. At least two of these genes are active: one corresponds to the previously isolated Rx1 gene that confers resistance to potato virus X, while the other corresponds to the Gpa2 gene that confers resistance to the potato cyst nematode Globodera pallida. The proteins encoded by the Gpa2 and the Rx1 genes share an overall homology of over 88% (amino-acid identity) and belong to the leucine-zipper, nucleotide-binding site, leucine-rich repeat (LZ-NBS-LRR)-containing class of plant resistance genes. From the sequence conservation between Gpa2 and Rx1 it is clear that there is a direct evolutionary relationship between the two proteins. Sequence diversity is concentrated in the LRR region and in the C-terminus. The putative effector domains are more conserved suggesting that, at least in this case, nematode and virus resistance cascades could share common components. These findings underline the potential of protein breeding for engineering new resistance specificities against plant pathogens in vitro.