Liu Furong, Zhang Weiguo, Schwessinger Benjamin, Wei Tong, Ruan Deling, Ronald Pamela
Department of Plant Pathology and the Genome Center, University of California, Davis, Davis, CA, United States.
Faculty of Life Science, Northwest University, Xi'an, China.
Front Plant Sci. 2020 Feb 6;11:49. doi: 10.3389/fpls.2020.00049. eCollection 2020.
The rice XA21 and XA3 pattern receptor kinases, derived from and an cultivar Wase Aikoku 3, respectively, confer resistance to strains of the Gram-negative bacterium pv. (), the causal agent of rice bacterial blight disease. Previously, we showed that transfer of to the model rice cultivar Kitaake enhances resistance to . In this manuscript we demonstrate that Kitaake expressing confers resistance to strain PXO79 and that the stress-related marker genes and are upregulated in -infected rice leaves. We also show that rice somatic embryogenesis receptor kinase 2 (OsSERK2) positively regulates XA3-mediated immunity in Kitaake. We found that overexpression of XA21 binding protein 15 (XB15) and XB24, two negative regulators of XA21-mediated immunity, do not affect XA3-mediated immunity in the Kitaake genetic background. Our results indicate that the rice immune receptors XA21 and XA3 employ both shared and distinct signaling components in their response to . The results are important to further understand pathogen-associated molecular pattern (PAMP)-triggered immunity in rice. Furthermore, the presence of Kitaake rice carrying will facilitate genetic research to study the XA3-mediated immunity.
水稻XA21和XA3模式识别受体激酶分别来源于籼稻品种IR24和粳稻品种早生爱国3，可赋予水稻对革兰氏阴性细菌稻黄单胞菌水稻致病变种（Xoo）的抗性，Xoo是水稻白叶枯病的病原菌。此前，我们发现将XA21导入模式水稻品种 Kitaake可增强其对Xoo的抗性。在本论文中，我们证明了表达XA3的Kitaake对Xoo菌株PXO79具有抗性，且在受Xoo侵染的Kitaake水稻叶片中，与胁迫相关的标记基因PAL和PR1被上调。我们还表明，水稻体细胞胚胎发生受体激酶2（OsSERK2）在Kitaake中正向调控XA3介导的免疫反应。我们发现，XA21介导免疫反应的两个负调控因子XA21结合蛋白15（XB15）和XB24的过表达，在Kitaake遗传背景下并不影响XA3介导的免疫反应。我们的结果表明，水稻免疫受体XA21和XA3在对Xoo的反应中使用了共同和不同的信号成分。这些结果对于进一步了解水稻中病原体相关分子模式（PAMP）触发的免疫反应具有重要意义。此外，携带XA3的Kitaake水稻的存在将有助于开展遗传研究以探究XA3介导的免疫反应。
