Background

Long non-coding RNAs (LncRNAs) have emerged as important regulators in many physiological processes in plant. By high-throughput RNA-sequencing, many pathogen-associated LncRNAs were mapped in various plants, and some of them were proved to be involved in plant defense responses. The rice blast disease caused by Magnaporthe oryzae (M. oryzae) is one of the most destructive diseases in rice. However, M. oryzae-induced LncRNAs in rice is yet to be studied.

Findings

We investigated rice LncRNAs that were associated with the rice blast fungus. Totally 83 LncRNAs were up-regulated after blast fungus infection and 78 were down-regulated. Of them, the natural antisense transcripts (NATs) were the most abundant. The expression of some LncRNAs has similar pattern with their host genes or neighboring genes, suggesting a cis function of them in regulating gene transcription level. The deferentially expressed (DE) LncRNAs and genes co-expression analysis revealed some LncRNAs were associated with genes known to be involved in pathogen resistance, and these genes were enriched in terpenoid biosynthesis and defense response by Gene Ontology (GO) enrichment analysis. Interestingly, one of up-regulated DE-intronic RNA was derived from a jasmonate (JA) biosynthetic gene, lipoxygenase RLL (LOX-RLL). Levels of JAs were significantly increased after blast fungus infection. Given that JA is known to regulate blast resistance in rice, we suggested that LncRNA may be involved in JA-mediated rice resistance to blast fungus.

Conclusions

This study identified blast fungus-responsive LncRNAs in rice, which provides another layer of candidates that regulate rice and blast fungus interactions.

中文翻译：

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长非编码RNA响应稻瘟病真菌感染。

背景

长的非编码RNA（LncRNA）已成为植物许多生理过程中的重要调控因子。通过高通量RNA测序，许多病原体相关的LncRNA被定位在各种植物中，其中一些被证明与植物防御反应有关。引起的稻瘟病稻瘟病菌（稻瘟病菌）是水稻的最具破坏性的疾病之一。然而，水稻中米曲霉诱导的LncRNA尚待研究。

发现

我们调查了与稻瘟病真菌相关的水稻LncRNA。原始真菌感染后，共有83个LncRNA上调，而78个LncRNA下调。其中，自然反义转录本（NAT）最丰富。一些LncRNA的表达与其宿主基因或邻近基因具有相似的模式，这表明一个顺式在调节基因转录水平中的功能。差异表达（DE）LncRNA和基因共表达分析显示，一些LncRNA与已知与病原体抗性有关的基因相关联，并且通过基因本体论（GO）富集分析，这些基因在萜类生物合成和防御反应中得到了丰富。有趣的是，上调的DE-内含子RNA之一来自于茉莉酸（JA）生物合成基因脂氧化酶RLL（LOX-RLL）。原始真菌感染后JAs水平显着增加。鉴于JA已知可以调节水稻的稻瘟病抗性，我们建议LncRNA可能参与JA介导的水稻对稻瘟病的抗性。

结论

这项研究在水稻中鉴定出了对稻瘟病菌具有响应性的LncRNA，从而提供了另一层候选物来调节水稻与稻瘟病菌的相互作用。