Analysis of the diversity and function of the alleles of the rice blast resistancegenesPiz-t,PitaandPikin 24 rice cultivars

• Published in: 农业科学学报（英文） Vol. 15; no. 7; pp. 1423 - 1431
• Main Author: WANG Yan ZHAO Jia-ming ZHANG Li-xia WANG Ping WANG Shi-wei WANG Hui WANG Xiao-xi LIU Zhi-heng ZHENG Wen-jing
• Format: Journal Article
• Language: English
• Published: Plant Protection Colege, Shenyang Agricultural University, Shenyang 110866, P.R.China%Agricultural Crops Molecular Improving Laboratory, Liaoning Academy of Agricultural Sciences, Shenyang 110161, P.R.China%Department of Plant Pathology, China Agricultural University, Beijing 100193, P.R.China 2016
• Subjects: 中国农业科学院; 基因组不稳定性; 多样性; 抗稻瘟病基因; 水稻品种; 水稻白叶枯病菌; 稻瘟病抗性基因; 等位基因; avirulence gene; resistance gene; genetic evolution; aleles; function
• ISSN: 2095-3119; 2352-3425
• DOI: 10.1016/S2095-3119(15)61207-2

Understanding the sequence diversity of rice blast resistance genes is important for breeding new resistant rice cultivars against the rice blast fungusMagnaporthe oryzae. In this study, we selected 24 rice cultivars with different genetic back-grounds to study the alelic diversity of rice blast resistance genesPiz-t, Pitaand Pik. For Piz-t, a total of 17 alelic types were found within the 24 cultivars. Blast inoculations showed that most of the mutations can affect the function of the resistance gene. For Pita, except for the difference at the 918th amino acid, a majority of the 21 mutations were detected among the cultivars. Inoculations with blast isolates carryingAvr-Pita revealed that cultivars with mutations in other sites except for the 918th amino acid did not affect the function of thePita gene. ForPik, a total of six alelic types were found within the 24 cultivars, but ifve of them lost the function of the resistance gene. In addition, we found thatPiz-t, Pita and Pik were expressed constitutively in the 24 rice cultivars and the expression level was not related to resistance. Our results have provided the sequence diversity information of the resistance genesPiz-t, Pita and Pik among the popular rice cultivars grown in the northeast region of China. Keywords：resistance gene, avirulence gene, aleles, function, genetic evolution zae（M. oryzae）, is one of the most destructive diseases in rice production worldwide. Over the years, comprehensive studies on rice blast resistance have been conducted （Silue et al. 1992）. The resistance in newly cultivated rice cultivars to M. oryzae can be lost quickly due to the high level of instability in the genome of the fungus （Bonmanet al. 1992）. Previous studies show that cultivars with durable and broad-spectrum resistance againstM. oryzae carry multiple major resistance （R） and minor resistance genes （Liuet al. 2014）. An effective way to control rice blast disease is, therefore, to breed rice cultivars with multiple R and QTL genes. To date, over 83 rice blast R genes have been identiifed, and are distributed on 11 rice chromosomes except Received 22 May, 2015 Accepted 26 October, 2015 WANG Yan, E-mail： 8806wy@163.com; Correspondence LIU Zhi-heng, Tel： ＋86-24-23738857, E-mail： lzhh1954@163.com; ZHENG Wen-jing, Tel： ＋86-24-31021081, E-mail： zwj27@126. com ＊These authors contributed equaly to this study. ？ 2016, CAAS. Al rights reserved. Published by Elsevier Ltd. doi： 10.1016/S2095-3119（15）61207-2 1. Introduction Rice blast disease, caused by the fungusMagnaporthe ory-