Main content area

Detection and profiling of circular RNAs in uninfected and maize Iranian mosaic virus-infected maize

Ghorbani, Abozar, Izadpanah, Keramatollah, Peters, Jonathan R., Dietzgen, Ralf G., Mitter, Neena
Plant science 2018 v.274 pp. 402-409
Maize Iranian mosaic virus, Northern blotting, biotic stress, chemical bonding, corn, crops, exons, gene expression regulation, humans, intergenic DNA, metabolism, microRNA, non-coding RNA, plant diseases and disorders, plant viruses, quantitative polymerase chain reaction, reverse transcriptase polymerase chain reaction, sequence analysis, two-dimensional gel electrophoresis, viruses, Iran
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.