Recent advances in small RNA mediated plant-virus interactions

Abstract

Small RNAs (sRNA) are reported to play pivotal roles in the epigenetic and post-transcriptional regulation of gene expression during growth, development, and stress response in plants. Recently, the involvement of two different classes of sRNAs namely, miRNAs (microRNAs), and siRNAs (small interfering RNAs) in biotic stress response has been underlined. Notably, during virus infection, these sRNAs deploy antiviral defense by regulating the gene expression of the modulators of host defense pathways. As a counter defense, viruses have evolved strategic pathways involving the production of suppressors that interfere with the host silencing machinery. This molecular arms race between the sophisticated gene regulatory mechanism of host plants fine-tuned by sRNAs and the defense response exhibited by the virus has gained much attention among the researchers. So far, several reports have been published showing the mechanistic insights on sRNA-regulated defense mechanism in response to virus infection in several crop plants. In this context, our review enumerates the molecular mechanisms underlying host immunity against viruses mediated by sRNAs, the counter defense strategies employed by viruses to surpass this immunogenic response and the advances made in our understanding of plant-virus interactions. Altogether, the report would be insightful for the researchers working to decode the sRNA-mediated defense response in crop plants challenged with virus infection.

Keywords:

• Small RNA (sRNA)
• microRNA (miRNA)
• small interfering RNA (siRNA)
• plant immunity
• plant-virus interactions
• antiviral defense
• DNA methylation

Acknowledgements

The authors are thankful to DBT-eLibrary Consortium (DeLCON) for providing access to e-resources.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was financially supported by the core grant of National Institute of Plant Genome Research (NIPGR), New Delhi, India and TATA Innovation Fellowship awarded to Dr. Manoj Prasad by the Department of Biotechnology (DBT), Ministry of Science & Technology, Govt. of India, India (File no. BT/HRD/35/01/02/2017). Ashish Prasad acknowledges the Council of Scientific and Industrial Research, Govt. of India, India for the award of research fellowship. Dr. Mehanathan Muthamilarasan acknowledges the INSPIRE Faculty Award from the Department of Science and Technology, Govt. of India, India.