Sequence Variation and Recognition Specificity of the Avirulence Gene AvrPiz-T in Magnaporthe Oryzae Field Populations
Sequence Variation and Recognition Specificity of the Avirulence Gene AvrPiz-T in Magnaporthe Oryzae Field Populations
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稻瘟病田间无毒基因AvrPiz-T的序列变异和识别特异性
DOI：
10.4172/2165-8056.1000113
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发表时间：
2014-07
期刊：
影响因子：
--
通讯作者：
Thomas K. Mitchell
中科院分区：
文献类型：
--
作者：
Wei-Chiang Shen;Guodong Lu;Baohua Wang;Thomas K. Mitchell
稻瘟病菌（Magnaporthe）是一种严重危害水稻生产的病原菌。目前，最有效的病害控制方法是通过将抗性（R）基因导入优良品种来部署宿主抗性。每个R基因的功能依赖于病原体的无毒（AVR）基因的特异性识别。然而，由于田间种群中AVR基因的突变，引入的抗性可以在几年内被分解。从一些案例研究中可以看出，AVR的突变模式是不同的。因此，对AVR基因序列多样性的认识是引入新的抗稻瘟病基因的基础。在本研究中，我们重点研究了一个新发现的AVR基因AvrPiz-t。我们PCR扩增了AvrPiz-t的开放阅读框（ORF）和启动子区，以检测711株M.收集了来自38个国家和地区的数据。通过测序和Southern杂交的扩增位点，在ORF中的多态性的菌株进行分组的基础上的突变类型和位点。计算该基因的自然选择强度，并应用致病性测定来评估AvrPiz-t ORF/启动子多态性与毒力之间的关联。总之，在AvrPiz-t基因座的序列被揭示包含在启动子和ORF区域的变化。这个位点正在经历相对较强的正选择。编码序列的多样性和转座因子在启动子区的插入使M。从而逃避宿主中同源Piz-t R基因的识别。
Magnaporthe oryzae, the rice blast pathogen, causes significant annual yield loss of rice worldwide. Currently, the most effective disease control approach is deployment of host resistance through introduction of resistance (R) genes into elite cultivars. The function of each R gene relies on the specific recognition of an avirulence (AVR) gene of the pathogen. However, the introduced resistance can be broken down within a few years, due to mutation of the AVR genes in the field populations. It is known from a few case studies that AVR mutation patterns are different from one to another. Therefore, knowledge of AVR genes sequence diversity serves as fundamental background in introducing new resistance to control rice blast. In this study, we focused on a newly identified AVR gene AvrPiz-t. We PCR amplified open reading frames (ORFs) of AvrPiz-t as well as promoter regions to detect size variation at this locus in 711 isolates of M. oryzae collected from 38 countries and regions. Through sequencing and Southern hybridization of the amplified locus, strains with polymorphisms in the ORF were classified into groups based on mutation type and site. Natural selection intensity on this gene was calculated and pathogenicity assays were applied to evaluate the association between AvrPiz-t ORF/promoter polymorphism and virulence. In conclusion, sequences at the AvrPiz-t locus were revealed to contain variations at both promoter and ORF regions. This locus is undergoing a relatively strong positive selection. The diversity in coding sequence and the insertions of transposable elements in the promoter region enable M. oryzae to evade recognition by the cognate Piz-t R gene in the host.
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影响因子：
6.7
作者：
Chuma I;Isobe C;Hotta Y;Ibaragi K;Futamata N;Kusaba M;Yoshida K;Terauchi R;Fujita Y;Nakayashiki H;Valent B;Tosa Y
通讯作者：
Tosa Y
影响因子：
11.6
作者：
Orbach, MJ;Farrall, L;Valent, B
通讯作者：
Valent, B
影响因子：
11.4
作者：
Jia, Y;McAdams, SA;Valent, B
通讯作者：
Valent, B
DOI：
10.1631/jzus.b1100338
发表时间：
2012-06
期刊：
Journal of Zhejiang University SCIENCE B
影响因子：
--
作者：
Ping Li;B. Bai;Hong-Yan Zhang;Heng Zhou;Bo Zhou
通讯作者：
Ping Li;B. Bai;Hong-Yan Zhang;Heng Zhou;Bo Zhou
DOI：
10.3410/f.4512956.4369054
发表时间：
2010-08
期刊：
--
影响因子：
--
作者：
D. Ebbole
通讯作者：
D. Ebbole