Investigation of virus-induced defence modulations during plant-virus interactions

Abstract

Turnip mosaic virus (TuMV) is a single stranded RNA (sRNAs) virus belonging to the genus Potyvirus .Turnip mosaic virus has a wide host range including several important crop plants, making it economically significant. This study investigates the relation between a strain of TuMV and two model plant systems; Arabidopsis thaliana and Nicotiana benthamiana, focusing on the viral sequence, host gene expression and defence mechanisms, and viral derived small RNAs (viRNAs). Turnip mosaic virus has been well studied and characterised with 183 complete genome nucleotide sequences available in GenBank (5 June 2018). The TuMV isolate used in this study was sequenced and submitted to GenBank, as well as the original isolate collected in 1994, under the names TuMV-QLD1b and TuMV-QLD1a, respectively (accession numbers KX641465 and KX641466). The original TuMV isolate was PCR sequenced while the 2015 isolate was sequenced by deep RNA sequencing. A comparison between the two sequences showed minor variations with 18 singlenucleotide-polymorphisms (SNPs). Another aspect of the study involved the sequencing of a Cucumber mosaic virus (CMV) isolate (strain K) as well as an Australian Cauliflower mosaic virus (CaMV) isolate belonging to the genus Cucumovirus and Caulimovirus respectively. This strain of CaMV represents the first Australian isolate to be fully sequenced. Both the CMV and the CaMV