Iyer-Pascuzzi Anjali S, McCouch Susan R
Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA.
Mol Plant Microbe Interact. 2007 Jul;20(7):731-9. doi: 10.1094/MPMI-20-7-0731.
Though recessive resistance is well-studied in viral systems, little is understood regarding the phenomenon in plant-bacterial interactions. The Oryza sativa-Xanthomonas oryzae pv. orzyae pathosystem provides an excellent opportunity to examine recessive resistance in plant-bacterial interactions, in which nine of 30 documented resistance (R) genes are recessively inherited. Infestations of X. oryzae pv. oryzae, the causal agent of bacterial blight, result in significant crop loss and damage throughout South and Southeast Asia. Two recently cloned novel recessive R genes, xa5 and xa13, have yielded insights to this system. Like their viral counterparts, these bacterial recessive R gene products do not conform to the five commonly described classes of R proteins. New findings suggest that such genes may more aptly be viewed as mutations in dominant susceptibility alleles and may also function in a gene-for-gene manner. In this review, we discuss recent accomplishments in the understanding of recessively inherited R genes in the rice-bacterial blight pathosystem and suggest a new model for the function of recessive resistance in plant-bacterial interactions.
虽然隐性抗性在病毒系统中已得到充分研究，但对于植物与细菌相互作用中的这一现象却知之甚少。水稻-稻瘟病菌致病系统为研究植物与细菌相互作用中的隐性抗性提供了绝佳机会，在已记录的30个抗性（R）基因中，有9个是隐性遗传的。稻瘟病菌是水稻白叶枯病的病原体，其侵染会在南亚和东南亚地区导致严重的作物损失和损害。最近克隆的两个新型隐性R基因xa5和xa13，为该系统提供了新的见解。与病毒中的对应基因一样，这些细菌隐性R基因产物不符合通常描述的五类R蛋白。新的研究结果表明，这类基因可能更恰当地被视为显性感病等位基因中的突变，并且可能也以基因对基因的方式发挥作用。在这篇综述中，我们讨论了在理解水稻白叶枯病致病系统中隐性遗传R基因方面的最新成果，并提出了一个关于植物与细菌相互作用中隐性抗性功能的新模型。
