Evolutionary Dynamics of the Genomic Region Around the Blast Resistance Gene Pi-ta in AA Genome Oryza Species
Evolutionary Dynamics of the Genomic Region Around the Blast Resistance Gene Pi-ta in AA Genome Oryza Species
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DOI：
10.1534/genetics.109.108266
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发表时间：
2009-12-01
期刊：
影响因子：
3.3
通讯作者：
Caicedo, Ana L.
中科院分区：
文献类型：
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作者：
Lee, Seonghee;Costanzo, Stefano;Caicedo, Ana L.
该基因已被有效地应用于稻瘟病的防治。病害是世界上最具破坏性的植物病害之一。单个I氨基酸在。已知Pi-ta蛋白的918位点决定耐药特异性。为了了解目前的进化动态，我们研究了由7个AA基因组稻属（O. sativa）、O. rufipogon、O. nivara、O. meridionalis、O.glaberrima、O. barthii和O. glumaepatula)组成的159份材料的Pi-ta位点及其侧翼区域的序列。在与抗性表型相关的Pi-ta启动子区域附近发现了一个编码预测转座子的3364-bp片段。利用33个新鉴定的Pi-ta单倍型和18个新鉴定的Pi-ta蛋白变异进行单倍型网络分析，证实了紫堇与紫堇之间Pi-ta单倍型的进化关系。在紫叶花中，在Pi-la区发现了最近的方向选择，而在所有紫叶花类群中都没有发现明显的偏差锋中性进化。结果表明，所有优质抗性品种的Pi-ta基因渗入区大小均不小于5.4 Mb，而无Pi-la的品种则不大于5.4 Mb。这些发现表明，Pi-ta区域具有转座子和附加植物。在作物育种过程中，调节剂在广泛的选择压力下进化而来。
The race-specific resistance gene Pi-ta has been effectively used to control blast. disease, one of the most destructive plant diseases worldwide. A single I amino acid change at. the 918 position of the Pi-ta protein was known to determine resistance specificity. To understand the evolutionary dynamics present, we examined sequences of the Pi-ta locus and its flanking regions in 159 accessions composed of seven AA genome Oryza species: O. sativa, O. rufipogon, O. nivara, O. meridionalis, O.glaberrima, O. barthii, and O. glumaepatula. A 3364-bp fragment encoding a predicted transposon was found in the proximity of the Pi-ta promoter region associated with the resistance phenotype. Haplotype network analysis with 33 newly identified Pi-ta haplotypes and 18 newly identified Pi-ta protein variants demonstrated the evolutionary relationships of Pi-ta haplotypes between O. sativa and O. rufipogon. In O. rufipogon, the recent directional selection was found in the Pi-la region, while significant deviation front neutral evolution Was not found in all O. sativa groups. Results of sequence variation in flanking regions around Pi-ta in O. sativa suggest that the size of the resistant Pi-ta introgressed block was M least 5.4 Mb in all elite resistant cultivars but not in the cultivars without Pi-la. These findings demonstrate that the Pi-ta region with transposon and additional plant. modifiers has evolved under an extensive selection pressure during crop breeding.