Table_6_Overexpression of Arabidopsis Nucleotide-Binding and Leucine-Rich Repeat Genes RPS2 and RPM1(D505V) Confers Broad-Spectrum Disease Resistance in Rice.XLSX

The nucleotide-binding domain leucine-rich repeat (NLR) immune receptors play important roles in innate plant immunity. The activation of NLRs is specifically induced by their cognate effectors released from pathogens. Autoactive NLRs are expected to confer broad-spectrum resistance because they do not need cognate effectors to activate their immune responses. In this study, we demonstrated that the NLR genes RPS2 and RPM1(D505V) from Arabidopsis were autoactive in Oryza sativa and conferred broad-spectrum resistance to fungal pathogen Magnaporthe oryzae, bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo), and pest brown planthopper (BPH, Nilaparvata lugens Stål). These results revealed that interfamily transfer of dicot NLRs to monocot species could be functional. The transgenic plants displayed early and strong induction of reactive oxygen species (ROS), callose deposition, and expression of defense-related genes after challenged with M. oryzae. The transcriptome analysis showed that the expressions of some defense-related genes were primed to adapt the transformed autoactive NLRs in the transgenic plants. This study indicates that autoactive NLRs are a promising resource for breeding crops with broad-spectrum resistance and provides new insights for engineering disease resistance.

核苷酸结合结构域亮氨酸富集重复序列（NLR）免疫受体在植物先天免疫中发挥着至关重要的作用。NLR受体的激活特异性地由病原体释放的同源效应子所诱导。具有自身活性的NLR受体有望赋予广谱抗性，因为它们无需同源效应子即可激活其免疫反应。在本研究中，我们证实了拟南芥中的NLR基因RPS2和RPM1(D505V)在水稻中具有自身活性，并赋予对稻瘟病菌（Magnaporthe oryzae）、细菌性病原菌稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，简称Xoo）以及害虫褐飞虱（BPH，Nilaparvata lugens Stål）的广谱抗性。这些结果揭示了被子植物NLR受体向单子叶植物物种的家族间转移可能具有功能性。转基因植株在受到稻瘟病菌侵染后，表现出早期且强烈的活性氧（ROS）诱导、木质素沉积以及与防御相关的基因表达。转录组分析显示，某些与防御相关的基因表达已被预先激活，以适应转基因植株中的转化自身活性NLR。本研究表明，自身活性NLR是一类具有开发广谱抗性作物潜力的宝贵资源，并为疾病抗性的工程设计提供了新的洞见。