Molecular evolution of the Pi-ta gene resistant to rice blast in wild rice (Oryza rufipogon)
Molecular evolution of the Pi-ta gene resistant to rice blast in wild rice (Oryza rufipogon)
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DOI：
10.1534/genetics.108.089805
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发表时间：
2008-07-01
期刊：
影响因子：
3.3
通讯作者：
Lin, Tsan-Piao
中科院分区：
文献类型：
--
作者：
Huang, Chun-Lin;Hwang, Shih-Ying;Lin, Tsan-Piao
水稻对稻瘟病菌的抗性。由宿主R（抗性）基因Pi-ta和病原体Avr（无毒）基因AVR-pita的蛋白产物之间的物理相互作用触发。研究了栽培稻的祖先野生稻Pi-ta位点的基因型变异和抗感表型。在全球36个地点调查了Pi-ta基因的分子进化和功能适应。O. rufipogon与O. sativa，但与其它O. rufipogon基因。单倍型可以细分为两个不同的单倍型群，命名为H1和H2。H1源自H2，几乎没有变异，频率低，H2是常见的，是祖先形式。富含亮氨酸重复序列（LRR）结构域的比例较高，Pi-ta基因的低多态性可能是导致该突变的原因之一。主要是由其他假定的生理功能的反复选择性扫描和限制引起的。同时，我们提供的数据表明H1的LRR结构域中的氨基酸Ala-918与抗性表型密切相关。HI可能是最近在水稻的低温化过程中出现的，可能与稻瘟病病原-宿主从意大利小米转移到水稻的情况有关。
Rice blast disease resistance to the fungal pathogen Magnaporthe grisea. is triggered by a physical interaction between the protein products Of the host R (resistance) gene, Pi-ta, and the pathogen Avr (avirulence) gene, AVR-pita. The genotype variation and resistant/susceptible phenotype at the Pi-ta locus of wild rice (Oryza rufipogon), the ancestor of cultivated rice (O. sativa), was surveyed in 36 locations worldwide to study the molecular evolution and functional adaptation of the Pi-ta gene. The low nucleotide polymorphism of the Pi-ta gene of O. rufipogon was similar to that of O. sativa, but greatly differed from what has been reported for other O. rufipogon genes. The haplotypes can be subdivided into two divergent haplogroups named H1 and H2. HI is derived from H2, with nearly no variation and at a low frequency, H2 is common and is the ancestral form. The leucine-rich repeat (LRR) domain has a high ratio, and the low polymorphisin of the Pi-ta gene might. have primarily been caused by recurrent selective sweep and constraint by other putative physiological functions. Meanwhile, we provide data to show that the amino acid Ala-918 of H1 in the LRR domain has a close relationship with the resistant phenotype. HI might have recently arisen during rice domestification and may be associated with the scenario of a blast pathogen-host shift from Italian millet to rice.