Laboratory of Fruit Physiology and Molecular Biology, China Agricultural University, Beijing, China.
Institute of Laboratory Animal Science, Guizhou University of Traditional Chinese, Guiyang, China.
Plant Mol Biol. 2021 Oct;107(3):129-146. doi: 10.1007/s11103-021-01185-1. Epub 2021 Oct 1.
We reported an NBS-LRR gene, PsoRPM3, is highly expressed following RKN infection, initiating an HR response that promotes plant resistance. Meloidogyne spp. are root-knot nematodes (RKNs) that cause substantial economic losses worldwide. Screening for resistant tree resources and identifying plant resistance genes is currently the most effective way to prevent RKN infestations. Here, we cloned a novel TIR-NB-LRR-type resistance gene, PsoRPM3, from Xinjiang wild myrobalan plum (Prunus sogdiana Vassilcz.) and demonstrated that its protein product localized to the nucleus. In response to Meloidogyne incognita infection, PsoRPM3 gene expression levels were significantly higher in resistant myrobalan plum plants compared to susceptible plants. We investigated this difference, discovering that the - 309 to - 19 bp region of the susceptible PsoRPM3 promoter was highly methylated. Indeed, heterologous expression of PsoRPM3 significantly enhanced the resistance of susceptible tobacco plants to M. incognita. Moreover, transient expression of PsoRPM3 induced a hypersensitive response in tobacco, whereas RNAi-mediated silencing of PsoRPM3 in transgenic tobacco reduced this hypersensitive response. Several hypersensitive response marker genes were considerably up-regulated in resistant myrobalan plum plants when compared with susceptible counterparts inoculated with M. incognita. PsoPR1a (a SA marker gene), PsoPR2 (a JA marker gene), and PsoACS6 (an ET signaling marker gene) were all more highly expressed in resistant than in susceptible plants. Together, these results support a model in which PsoRPM3 is highly expressed following RKN infection, initiating an HR response that promotes plant resistance through activated salicylic acid, jasmonic acid, and ethylene signaling pathways.
我们报道了一个 NBS-LRR 基因，PsoRPM3，在 RKN 感染后高度表达，引发 HR 反应，促进植物抗性。Meloidogyne spp. 是根结线虫（RKNs），在全球范围内造成了巨大的经济损失。筛选抗性树木资源和鉴定植物抗性基因是目前预防 RKN 感染最有效的方法。在这里，我们从新疆野生巴旦杏（Prunus sogdiana Vassilcz.）中克隆了一个新的 TIR-NB-LRR 型抗性基因 PsoRPM3，并证明其蛋白产物定位于细胞核。在对 M. incognita 感染的反应中，抗性巴旦杏植株中 PsoRPM3 基因的表达水平明显高于敏感植株。我们研究了这种差异，发现易感 PsoRPM3 启动子的 -309 到-19 bp 区域高度甲基化。事实上，PsoRPM3 的异源表达显著增强了敏感烟草对 M. incognita 的抗性。此外，PsoRPM3 的瞬时表达在烟草中诱导了过敏反应，而 PsoRPM3 在转基因烟草中的 RNAi 介导沉默降低了这种过敏反应。与接种 M. incognita 的敏感对照相比，抗性巴旦杏植株中几种过敏反应标记基因的表达水平显著上调。与敏感植株相比，PsoPR1a（SA 标记基因）、PsoPR2（JA 标记基因）和 PsoACS6（ET 信号标记基因）在抗性植株中的表达水平更高。综上所述，这些结果支持了 PsoRPM3 在 RKN 感染后高度表达，引发 HR 反应，通过激活水杨酸、茉莉酸和乙烯信号通路促进植物抗性的模型。
