Unique features of the rice blast resistance Pish locus revealed by large scale retrotransposon-tagging.
Unique features of the rice blast resistance Pish locus revealed by large scale retrotransposon-tagging.
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DOI：
10.1186/1471-2229-10-175
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发表时间：
2010-08-13
影响因子：
5.3
通讯作者：
Hirochika H
中科院分区：
文献类型：
--
作者：
Takahashi A;Hayashi N;Miyao A;Hirochika H
R基因介导的抗病性是植物对病原菌最有效的免疫机制之一。到目前为止，已经分离出一些调节植物免疫的主要步骤的组分，然而，R蛋白下游防御信号的分子解剖仍有待完成。此外，已知R基因是高度可变的，然而，负责这种可变性的分子机制仍然不清楚。为了确定R基因介导的水稻抗性所需的新因素，我们使用了水稻插入突变体系，诱导的内源性反转录转座子Tos 17，在涉及稻瘟病菌的遗传筛选。我们使用高通量程序用真菌接种了41，119个突变株系，并鉴定了86个抗性降低的突变株系。基因组分析显示，86个品系中的72个含有编码核苷酸结合位点（NBS）和富含亮氨酸重复序列（LRR）结构域（NBS-LRR）蛋白的基因突变。遗传互补分析和致病性分析表明，该NBS-LRR基因编码Pish，该基因赋予对M.包含avrPish的文件夹。其他14个品系具有完整的Pish基因拷贝，表明它们可能在Pish下游的信号传导组分中含有突变。基因组分析表明，Pish及其邻近的3个NBS-LRR基因彼此高度相似，并且串联定位。Tos 17侧翼序列数据库的计算机分析显示，该区域是插入的“热点”。有趣的是，插入位点在这四个NBS-LRR基因中并不均匀分布，尽管它们在序列和表达水平上相似。在这项工作中，我们分离的R基因Pish，并确定了其他几个突变体参与Pish介导的抗性所需的信号转导。这些结果表明，我们的遗传方法是有效的和有用的揭示新的方面防御信号在水稻。此外，我们的数据提供了实验证据，R基因簇有可能成为转座因子插入植物基因组中的高度首选目标。基于这一发现，一个可能的机制，潜在的高变异性的R基因进行了讨论。
R gene-mediated resistance is one of the most effective mechanisms of immunity against pathogens in plants. To date some components that regulate the primary steps of plant immunity have been isolated, however, the molecular dissection of defense signaling downstream of the R proteins remains to be completed. In addition, R genes are known to be highly variable, however, the molecular mechanisms responsible for this variability remain obscure. To identify novel factors required for R gene-mediated resistance in rice, we used rice insertional mutant lines, induced by the endogenous retrotransposon Tos17, in a genetic screening involving the rice blast fungus Magnaporthe oryzae. We inoculated 41,119 mutant lines with the fungus using a high throughput procedure, and identified 86 mutant lines with diminished resistance. A genome analysis revealed that 72 of the 86 lines contained mutations in a gene encoding a nucleotide binding site (NBS) and leucine rich repeat (LRR) domain-containing (NBS-LRR) protein. A genetic complementation analysis and a pathogenesis assay demonstrated that this NBS-LRR gene encodes Pish, which confers resistance against races of M. oryzae containing avrPish. The other 14 lines have intact copies of the Pish gene, suggesting that they may contain mutations in the signaling components downstream of Pish. The genome analysis indicated that Pish and its neighboring three NBS-LRR genes are high similar to one another and are tandemly located. An in silico analysis of a Tos17 flanking sequence database revealed that this region is a "hot spot" for insertion. Intriguingly, the insertion sites are not distributed evenly among these four NBS-LRR genes, despite their similarity at the sequence and expression levels. In this work we isolated the R gene Pish, and identified several other mutants involved in the signal transduction required for Pish-mediated resistance. These results indicate that our genetic approach is efficient and useful for unveiling novel aspects of defense signaling in rice. Furthermore, our data provide experimental evidence that R gene clusters have the potential to be highly preferred targets for transposable element insertions in plant genomes. Based on this finding, a possible mechanism underlying the high variability of R genes is discussed.
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DOI：
10.1073/pnas.92.14.6597
发表时间：
1995-07-03
影响因子：
11.1
作者：
CENTURY, KS;HOLUB, EB;STASKAWICZ, BJ
通讯作者：
STASKAWICZ, BJ
影响因子：
3.3
作者：
Liu, Xinqiong;Lin, Fei;Pan, Qinghua
通讯作者：
Pan, Qinghua
影响因子：
11.6
作者：
Luck, JE;Lawrence, GJ;Ellis, JG
通讯作者：
Ellis, JG
影响因子：
7
作者：
Fiston-Lavier, Anna-Sophie;Anxolabehere, Dominique;Quesneville, Hadi
通讯作者：
Quesneville, Hadi
影响因子：
7.2
作者：
HIEI, Y;OHTA, S;KUMASHIRO, T
通讯作者：
KUMASHIRO, T