由III型效应因子诱导的R基因表达触发了大米的抗病性
Keyu Gu1, Bing Yang, Dongsheng Tian
1Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore.
Nature
|June 24, 2005
概括
植物疾病耐药性 (R) 基因和病原体激烈性 (avr) 基因决定了特异性. 这项研究表明,大米的Xa27基因表达是由细菌的AvrXa27效应器诱导的,从而赋予了耐药性.
科学领域:
- 植物病理学 植物病理学
- 分子遗传学 分子遗传学
- 植物与微生物的相互作用
背景情况:
- 植物疾病耐药性依赖于R基因识别病原体avr基因.
- 基因对基因特异性的分子基础仍然不完全理解.
- 了解这种相互作用对于作物保护至关重要.
研究的目的:
- 克隆和表征大米R基因Xa27及其相似的细菌avrXa27基因.
- 阐明Xa27介导的抗病性背后的机制.
- 研究差异性基因表达在R基因特异性中的作用.
主要方法:
- 克隆 Xa27 和 avrXa27 基因.
- 对抗性和敏感性Xa27等位基因的比较分析.
- 用大米植物进行细菌挑战测试.
- 对Xa27基因表达模式的分析.
- 对Xa27.27.的宫外表达研究.
主要成果:
- 同样的蛋白质被抗性和敏感的Xa27基因编码.
- 在米中,Xa27表达是通过Xanthomonas oryzae pv.v.的挑战而特别诱导的. 带有avrXa27.27.27.27.27.27.27.27.27.27.27.27.27.27.27.27.27.28.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.28.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.29.24.29.29.29.29.29.29.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.24.25.24.44.44.44.44.
- AvrXa27是一种核定位的III型效应器.
- 诱导的Xa27表达局限于受感染的组织.
- 宫外Xa27表达赋予了对相容的病原体菌株的耐药性.
结论:
- 米Xa27特异性涉及由AvrXa27效应器触发的差异性基因表达.
- 在AvrXa27效应器诱导Xa27抗性基因的局部表达.
- 这项研究提供了关于植物R基因功能和特异性的分子机制的见解.
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