Isolation and diversity analysis of resistance gene analogues (RGAs) from cultivated and wild strawberries
Isolation and diversity analysis of resistance gene analogues (RGAs) from cultivated and wild strawberries
复制标题
DOI：
10.1007/s00438-004-1079-4
复制
发表时间：
2004-11-01
影响因子：
3.1
通讯作者：
Díaz Ricci, JC
中科院分区：
文献类型：
--
作者：
Martínez Zamora, MG;Castagnaro, AP;Díaz Ricci, JC
根据已克隆的植物抗病基因的核苷酸结合位点（NBS）保守区设计简并寡核苷酸引物，从野生和栽培草莓中分离抗病基因类似物（RGAs）。从两个相关的野生种，野草莓（Fragaria vesca）和F. chiloensis，和六个不同的草莓x ananassa品种。除GAV-3外，草莓RGAs的氨基酸序列与拟南芥、烟草和亚麻的TIR（Toll Interleukin I Receptor）型R基因具有很强的相似性，表明它们有共同的祖先。GAV-3与非TIR型的关系更为密切。进一步的研究表明，重组水平和非同义/同义替换的比例在家庭内是低的。这些数据表明，NBS编码序列的RGA在草莓受到逐渐积累的突变导致纯化选择，而不是多样化的过程。本文是对草莓中RGAs的首次报道。
Degenerate oligonucleotide primers, designed based on conserved regions of Nucleotide Binding Site (NBS) domains from previously cloned plant resistance genes, were used to isolate Resistance Gene Analogues (RGAs) from wild and cultivated strawberries. Seven distinct families of RGAs of the NBS-LRR type were identified from two related wild species, Fragaria vesca and F. chiloensis, and six different Fragaria x ananassa cultivars. With one exception (GAV-3), the deduced amino acid sequences of strawberry RGAs showed strong similarity to TIR (Toll Interleukin I Receptor)-type R genes from Arabidopsis, tobacco and flax, suggesting the existence of common ancestors. GAV-3 seemed to be more closely related to the non-TIR type. Further studies showed that the recombination level and the ratio of non-synonymous to synonymous substitutions within families were low. These data suggest that NBS-encoding sequences of RGAs in strawberry are subject to a gradual accumulation of mutations leading to purifying selection, rather than to a diversifying process. The present paper is the first report on RGAs in strawberry.