水稻广谱、持久抗褐飞虱主基因Bph3的功能分析

Brown planthopper is one of the most destructive insect, heavily threaten the global ric production. Application of resistance cultivar to control the insect is considered the most economic and efficent means. The Sri Lankan landrace rice, Rathu Heenati (RH), displays strong and broad-spectrum resistance to all the four BPH biotypes. RH carries a major BPH resistance locus Bph17, and the locus has been successfully cloned in our previous study. Bph17 is a resistance gene cluster including four high homologous receptor kinases and the proteins interacting with the receptor kinases also have been indentified using yeast two-hybrid. To explore the response of the four receptor kinases to different biotype BPH and clarify the broad-spectrum resistance mechanism of Bph17, single or multiple receptor kinase transgenic rice plants would be evaluated for BPH resistance. RNAi, over-expression, phosphorylation, degradation and enzyme activity assay et al experiments will be conducted in order to elucidate the BPH resistance mechanism of the four receptor kinases in this program. The achievement of this program will be very significant for understanding the mechanism of piercing-sucking insect resistance and controlling BPH damage.

褐飞虱为水稻主要害虫之一，严重威胁着世界水稻生产。抗褐飞虱主基因Bph3具有广谱、持久的褐飞虱抗性。项目组前期完成了该基因的图位克隆，表明该位点包含有四个编码凝集素类受体激酶（OsLecRKs）的同源基因,四个OsLecRKs对褐飞虱的抗性存在累加作用；并初步通过酵母双杂等实验获得了其互作蛋白。本项目拟利用含有单个或多个基因的转基因材料，进行不同生物型褐飞虱抗性鉴定，研究Bph3位点四个同源基因与不同褐飞虱生物型间的互作，探索Bph3褐飞虱广谱、持久抗性机制。通过RNAi和过表达、磷酸化、体外降解、胼胝质检测及水稻植株和褐飞虱体内β-1,3-葡聚糖酶活测定等，研究OsLecRKs与β-1,3-葡聚糖酶互作是如何产生褐飞虱抗性，探索四个受体激酶抗褐飞虱的分子机制。本项目的完成不仅对阐明水稻抗吸汁类害虫的机制具有重要的理论意义，而且对褐飞虱的生物防治及水稻的安全生产也将具有十分重要的应用价值。

褐飞虱为水稻主要害虫之一，严重威胁着世界水稻生产。Bph3具有广谱、持久的褐飞虱抗性。项目组前期完成了该基因的精细定位，发现该区间包含有四个高度同源的凝集素类受体激酶（OsLecRKs）的基因。本研究发现四个OsLecRKs对褐飞虱的抗性存在累加作用，表明Bph3的广谱、持久抗性由四个基因共同控制。通过酵母双杂、BiFC和Pull down实验表明，OsLecRK2和OsLecRK3可与胼胝质降解相关的β-1,3-葡聚糖酶OsGNS16互作，并将其磷酸降解，引起胼胝质的积累，从而产生褐飞虱抗性。本研究解析了Bph3抗褐飞虱的机制，为水稻抗褐飞虱分子机制的阐明奠定了基础。