华南农大发现miRNA介导病毒与水稻互作

南方水稻黑条矮缩病毒(SRBSDV)是最近出现的一种水稻病毒，已经蔓延整个亚洲。这种毁灭性的病毒引起水稻植株在不同生长阶段，产生各种症状。micrornA(miRNA)，一群21-24 nt的RNA分子，是植物发育过程和应激反应过程的重要调节剂。SRBSDV感染必然会影响水稻miRNA的表达丰度，然而，尚未有报道说明这种新出现的病毒与宿主miRNA之间的相互作用。

华南农业大学的周国辉教授带领的研究团队探讨了miRNA调节水稻SRBSDV感染应答的机制以及水稻病毒疾病的发病机理，研究成果发表在7月刊的Virus Research上。

研究人员选取了接种病毒3，9，15和20 dpi(days post-inoculation)四个时间点，利用miRNA微阵列分析(芯片分析项目由联川生物承担完成)确定各时间点水稻受SRBSDV感染后，miRNA应答表达模式。结果显示，水稻植株中56个miRNA的表达水平发生了改变，这些变化根据各自的时间表达动力学可归类到八个不同的调节模式。来自6个miRNA家庭(miR164，R396，R530，R1846，R1858和R2097)的14个miRNA在20dpi被显著调节。

研究人员用RT-QPCR检验在3，9和15 dpi，这些家庭成员和它们假定靶基因之间表达水平的相关性。miR164，R396，R530和R1846家族的一些成员被发现与各自的靶基因在SRBSDV感染后3至15days时的表达水平存在正相关或负相关，而在更多的情况下，水稻miRNA与它们的靶基因在接种后的阶段是不相关的，这表明一些另外的因素可能介入了水稻的miRNA与靶基因之间的相互作用。

由miR164，R396，R530，R1846和R1858家族靶向结合的水稻基因的功能显示，这些基因与症状的发展有关。这些结果有助于深入了解miRNA介导的SRBSDV与水稻的相互作用，进一步阐明水稻miRNA表达与调控的复杂网络和分子机制。

原文摘要：

MicroRNAs responding to southern rice black-streaked dwarf virus infection and their target genes associated with symptom development in rice

Donglin Xu, Guiping Mou, Kang Wang, Guohui Zhou

Southern rice black-streaked dwarf virus (SRBSDV) is a recently emerged rice virus that has spread across Asia. This devastating virus causes rice plants to produce a variety of symptoms during different growth stages. MicroRNAs (miRNAs) comprise a large group of 21–24-nt RNA molecules that are important regulators of plant development processes and stress responses. In this study, we used microarray profiling to investigate rice miRNAs responding to SRBSDV infection at 3, 9, 15, and 20 days post-inoculation (dpi). expression levels of 56 miRNAs were altered in SRBSDV-infected rice plants, with these changes classified into eight different regulation patterns according to their temporal expression dynamics. Fourteen miRNAs belonging to six families (miR164, R396, R530, R1846, R1858, and R2097) were significantly regulated at 20 dpi. We used RT-qPCR to search for expression level correlations between members of these families and their putative targets at 3, 9, and 15 dpi. Some members of the miR164, R396, R530, and R1846 families were found to be positively or negatively correlated with their respective targets during 3–15 days after SRBSDV infection, whereas in more cases the rice miRNAs were not in correlation with their targets along the post-inoculation period, suggesting that some additional factors may be involved in rice miRNA-target interactions. The reported functions of rice genes targeted by the miR164, R396, R530, R1846, and R1858 families indicated that these genes are associated with symptom development. These results provide insights into miRNA-mediated SRBSDV-rice interactions.

作者：联川生物