School of Bioengineering, Dalian University of Technology, Dalian, 116024, China.
Plant Cell Rep. 2021 Oct;40(10):1831-1844. doi: 10.1007/s00299-021-02746-w. Epub 2021 Jul 6.
MiR394 plays a negative role in tomato resistance to late blight. The lncRNA40787 severing as an eTM for miR394 to regulate LCR and exerting functions in tomato resistance. Tomato (Solanum lycopersicum), which was used as model species for studying the mechanism of plant disease defense, is susceptible to multiple pathogens. Non-coding RNA (ncRNA) has a pivotal role in plants response to biological stresses. It has previously been observed that the expression level of miR394 changed significantly after the infection of various pathogens. However, there has been no detailed investigation of the accumulated or suppressed mechanism of miR394. Our previous study predicted three lncRNAs (lncRNA40787, lncRNA27177, and lncRNA42566) that contain miR394 endogenous target mimics (eTM), which may exist as the competitive endogenous RNAs (ceRNAs) of miR394. In our study, the transcription levels of these three lncRNAs were strongly up-regulated in tomato upon infection with P. infestans. In contrast with the three lncRNAs, the accumulation of miR394 was significantly suppressed. Based on the expression pattern, and value of minimum free energy (mfes) that represents the binding ability between lncRNA and miRNA, lncRNA40787 was chosen for further investigation. Results showed that overexpression of lncRNA40787 reduced the expression of miR394 along with decreased lesion area and enhanced disease resistance. Overexpression of miR394, however, decreased the expression of its target gene Leaf Curling Responsiveness (LCR), and suppressed the synthesis components genes of jasmonic acid (JA), depressing the resistance of tomato to P. infestans infection. Taken together, our findings indicated that miR394 can be decoyed by lncRNA40787, and negatively regulated the expression of LCR to enhance tomato susceptibility under P. infestans infection. Our study provided detailed information on the lncRNA40787-miR394-LCR regulatory network and serves as a reference for future research.
miR394 在番茄晚疫病抗性中发挥负调控作用。lncRNA40787 作为 miR394 的 eTM 来调控 LCR，并在番茄抗性中发挥功能。番茄（Solanum lycopersicum）作为研究植物疾病防御机制的模式物种，易受多种病原体的侵害。非编码 RNA（ncRNA）在植物应对生物胁迫中起着关键作用。先前观察到，miR394 的表达水平在受到各种病原体感染后显著变化。然而，对于 miR394 的积累或抑制机制尚未进行详细研究。我们之前的研究预测了三个含有 miR394 内源性靶标模拟物（eTM）的 lncRNA（lncRNA40787、lncRNA27177 和 lncRNA42566），它们可能作为 miR394 的竞争性内源 RNA（ceRNA）存在。在本研究中，P. infestans 感染后番茄中这三个 lncRNA 的转录水平强烈上调。与这三个 lncRNA 相反，miR394 的积累显著受到抑制。基于表达模式和最小自由能（mfes）值（代表 lncRNA 和 miRNA 之间的结合能力），选择 lncRNA40787 进行进一步研究。结果表明，lncRNA40787 的过表达降低了 miR394 的表达，同时减少了病斑面积并增强了抗病性。然而，miR394 的过表达降低了其靶基因叶片卷曲响应性（LCR）的表达，并抑制了茉莉酸（JA）合成成分基因的合成，从而抑制了番茄对 P. infestans 感染的抗性。综上所述，我们的研究结果表明，miR394 可以被 lncRNA40787 诱饵，并且在 P. infestans 感染下负调控 LCR 的表达，从而增强番茄的易感性。我们的研究为 lncRNA40787-miR394-LCR 调控网络提供了详细信息，为未来的研究提供了参考。
