Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, Iran; Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia 4072, QLD, Australia.
Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, Iran.
Plant Sci. 2018 Sep;274:402-409. doi: 10.1016/j.plantsci.2018.06.016. Epub 2018 Jun 20.
Circular RNAs (circRNAs) are covalently closed non-coding RNAs that are usually derived from exonic regions of genes, but can also arise from intronic and intergenic regions. Studies of circRNAs in humans, animals and several plant species have shown an altered population of circRNAs in response to abiotic and biotic stress. Recently it was shown that circRNAs also occur in maize, but it is unknown if maize circRNAs are responsive to stress. Maize Iranian mosaic virus (MIMV, genus Nucleorhabdovirus, family Rhabdoviridae) causes an economically important disease in maize and other gramineous crops in Iran. In this study, we used data from RNA-Seq of MIMV-infected maize and uninfected controls to identify differentially expressed circRNAs. Such circRNAs were confirmed by two-dimensional polyacrylamide gel electrophoresis, northern blot, RT-qPCR and sequencing. A total of 1443 circRNAs were identified in MIMV-infected maize and 1165 circRNAs in uninfected maize. Two hundred and one circRNAs were in common between MIMV-infected and uninfected samples. Of these, 155 circRNAs were up-regulated and 5 down-regulated in MIMV infected plants, compared to the uninfected control. This study for the first time identified and profiled circRNA expression in maize in response to virus infection. Moreover, we predict that 33 circRNAs may bind 23 maize miRNAs, possibly affecting plant metabolism and development. Our data suggest a role for circRNAs in plant cell regulation and response to biotic stress such as virus infection, and give new insights into the complexity of plant-microbe interactions.
环状 RNA（circRNAs）是共价闭合的非编码 RNA，通常来源于基因的外显子区域，但也可以来自内含子和基因间区域。对人类、动物和几种植物中 circRNAs 的研究表明，circRNAs 的群体在应对非生物和生物胁迫时会发生改变。最近的研究表明，circRNAs 也存在于玉米中，但尚不清楚玉米 circRNAs 是否对胁迫有反应。玉米伊朗 mosaic 病毒（MIMV，属核状病毒科，弹状病毒科）在伊朗和其他禾本科作物中引起一种重要的经济疾病。在这项研究中，我们使用了来自 MIMV 感染玉米和未感染对照的 RNA-Seq 数据来鉴定差异表达的 circRNAs。通过二维聚丙烯酰胺凝胶电泳、 northern blot、RT-qPCR 和测序对这些 circRNAs 进行了验证。在 MIMV 感染的玉米中鉴定出 1443 个 circRNAs，在未感染的玉米中鉴定出 1165 个 circRNAs。MIMV 感染和未感染样本中有 201 个 circRNAs 是共同的。其中，与未感染对照相比，在 MIMV 感染植物中有 155 个 circRNAs 上调，5 个下调。这项研究首次鉴定并分析了玉米对病毒感染的 circRNA 表达谱。此外，我们预测 33 个 circRNAs 可能与 23 个玉米 miRNA 结合，可能影响植物代谢和发育。我们的数据表明，circRNAs 在植物细胞的调控和对生物胁迫（如病毒感染）的反应中发挥作用，并为植物与微生物相互作用的复杂性提供了新的见解。
