Characterization and function of Tomato yellow leaf curl virus-derived small RNAs generated in tolerant and susceptible tomato varieties

Abstract Virus-tolerant plant, which allows the accumulation of virus and then generates virus-derived small RNAs (vsRNAs), is a valuable material to reveal the antiviral efficiency of vsRNAs. Here, a comparison of vsRNAs in Tomato yellow leaf curl virus tolerant and in susceptible tomato varieties showed the consistent trend of vsRNAs' distribution on virus genome, which is presented as an obvious characteristic. However, the expression level of vsRNA in tolerant variety is less than that in susceptible variety. Slicing targets of vsRNA-mediated viral transcripts were investigated using parallel analysis of RNA ends, and geminivirus DNA methylation was determined by bisulfite sequencing, which uncovered that not all vsRNAs participated in viral mRNA degradation and DNA methylation. Additionally, by comparing with the expression pattern of vsRNAs, viral DNA and mRNA, we proposed the quantity of vsRNAs is corresponding to the expression level of viral mRNA, while the virus-suppression of vsRNAs is not high-efficient.