Enhanced resistance to bacterial and oomycete pathogens by short tandem target mimic RNAs in tomato
Enhanced resistance to bacterial and oomycete pathogens by short tandem target mimic RNAs in tomato
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DOI：
10.1073/pnas.1814380116
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发表时间：
2019-02-12
影响因子：
11.1
通讯作者：
Baulcombe, David C.
中科院分区：
文献类型：
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作者：
Canto-Pastor, Alex;Santos, Bruno A. M. C.;Baulcombe, David C.
植物天然免疫系统中富含亮氨酸重复序列的核苷酸结合位点(NLR)蛋白受miR482/2118家族miRNAs的负调控，miR482/2118家族miRNAs是一类具有双重作用模式的22nT的miRNAs。第一，它们切割目标RNA，就像经典的21-NT miRNAs一样，第二，它们以目标RNA为模板触发二次siRNA生产。在这里，我们讨论miR482/2118家族对NLRmRNAs表达和抗病能力的影响程度。结果表明，番茄miR482/2118家族成员在功能上存在显著差异。MiR482亚家族的预测靶点是多个NLR mRNAs中的保守基序，而miR2118b则是由几个不同的NLR基因重排形成的非编码RNA靶点。从表达miR482/2118的短串联靶标模拟(STTM)RNA的RNA测序和降解组数据中，我们确认了这些miRNAs的不同靶点。虽然对NLR基因表达的影响不大，但番茄STTM品系对卵菌和细菌侵染表现出较强的抗性。这些数据暗示了一系列miRNAs和次级siRNAs在NLR RNAs调控中的RNA级联作用，并表明编码的NLR蛋白除了在其他地方已被很好描述的显性基因抗性之外，还在数量抗病中发挥作用。我们还说明了STTM RNA在一种生物技术方法中的应用，以提高高育种品种的数量抗病能力。
Nucleotide binding site leucine-rich repeat (NLR) proteins of the plant innate immune system are negatively regulated by the miR482/2118 family miRNAs that are in a distinct 22-nt class of miRNAs with a double mode of action. First, they cleave the target RNA, as with the canonical 21-nt miRNAs, and second, they trigger secondary siRNA production using the target RNA as a template. Here, we address the extent to which the miR482/2118 family affects expression of NLR mRNAs and disease resistance. We show that structural differences of miR482/2118 family members in tomato (Solanum lycopersicum) are functionally significant. The predicted target of the miR482 subfamily is a conserved motif in multiple NLR mRNAs, whereas for miR2118b, it is a noncoding RNA target formed by rearrangement of several different NLR genes. From RNA sequencing and degradome data in lines expressing short tandem target mimic (STTM) RNAs of miR482/2118, we confirm the different targets of these miRNAs. The effect on NLR mRNA accumulation is slight, but nevertheless, the tomato STTM lines display enhanced resistance to infection with the oomycete and bacterial pathogens. These data implicate an RNA cascade of miRNAs and secondary siRNAs in the regulation of NLR RNAs and show that the encoded NLR proteins have a role in quantitative disease resistance in addition to dominant gene resistance that has been well characterized elsewhere. We also illustrate the use of STTM RNA in a biotechnological approach for enhancing quantitative disease resistance in highly bred cultivars.