Rice blast and bacterial blight represent two of major diseases having devastating impact on the yield of rice in most rice-growing countries. Developments of resistant cultivars are the most economic and effective strategy to control these diseases. Here, we used CRISPR/Cas9-mediated gene editing to rapidly install mutations in three known broad-spectrum blast-resistant genes, Bsr-d1, Pi21 and ERF922, in an indica thermosensitive genic male sterile (TGMS) rice line Longke638S (LK638S). We obtained transgene-free homozygous single or triple mutants in T₁ generations. While all single and triple mutants showed increased resistance to rice blast compared with wild type, the erf922 mutants displayed the strongest blast resistance similar with triple mutants. Surprisingly, we found that Pi21 or ERF922 single mutants conferred enhanced resistance to most of tested bacterial blight. Both resistances in mutants were attribute to the up-regulation of SA- and JA-pathway associated genes. Moreover, phenotypic analysis of these single mutants in paddy fields revealed that there were no trade-offs between resistances and main agricultural traits. Together, our study provides a rapid and effective way to generate rice varieties with resistance to both rice blast and bacterial blight.

中文翻译：

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通过 CRISPR/Cas9 对稻瘟病和白叶枯病病的抗性增强的水稻品种工程

在大多数水稻种植国，稻瘟病和白叶枯病是对水稻产量造成毁灭性影响的两种主要疾病。开发抗病品种是控制这些病害最经济、最有效的策略。在这里，我们使用 CRISPR/Cas9 介导的基因编辑在籼热敏感基因雄性不育 (TGMS) 水稻品系 Longke638S (LK638S)中快速安装三个已知广谱抗稻瘟病基因Bsr-d1、Pi21和ERF922的突变。 . _{我们在 T 1}代中获得了无转基因纯合单或三突变体。虽然与野生型相比，所有单突变体和三突变体都显示出对稻瘟病的抗性增加，但erf922突变体表现出与三重突变体相似的最强稻瘟病抗性。令人惊讶的是，我们发现Pi21或ERF922单突变体对大多数受试细菌性枯萎病具有增强的抗性。突变体中的两种抗性都归因于 SA 和 JA 通路相关基因的上调。此外，对稻田中这些单一突变体的表型分析表明，抗性和主要农业性状之间没有权衡取舍。总之，我们的研究提供了一种快速有效的方法来产生对稻瘟病和白叶枯病具有抗性的水稻品种。