Molecular characterization of canna virus and detection of tick-borne viruses

Abstract

Cannas are the most popular ornamental flowers in Cannaceae family. However, cannas are under threat due to various virus infections, especially by Canna yellow mottle virus (CaYMV; Badnavirus). Badnavirus is a plant pararetrovirus (Family: Caulimoviridae) or DNA reverse transcribing virus with a genome size of 7.2-9.2 kb. Large scale spread of Badnavirus is primarily based on vegetative propagation in perennial hosts. Due to easy exposure to viruses during propagation, the mode of transmission of the virus is a key factor to study. The first transmission study was the plant-to-plant transmission, where infected and healthy plants were grown in the same pot, followed by soil-borne transmission where healthy plants were grown in the soil where infected plants were grown previously. Also, vector transmission, mechanical transmission, and nematodes transmission experiments were performed. A complete genome sequence of CaYMV-AP01 was obtained using massive parallel sequencing. BLAST confirmed the genome of CaYMV-AP01 shares 94% similarity with that of the CaYMV-AP (ginger sequence). There was no transmission of viruses to the healthy plants. Although CaYMV-AP01 was transmitted to healthy cannas in soil-borne transmission experiment. The research studied the infection and transmission of a new virus, CAYMV-AP01.

Additional research on the tick-borne viruses; Powassan virus (Flaviviridae, Flavivirus) and Heartland virus (Bunyaviridae, Phlebovirus), were studied which are infectious to humans. Primers were designed to identify the viruses and quality and sensitivity tests were carried out. A plasmid carrying PCR diagnostic inserts was used as a positive control and to mimic infected samples. Similarly, primers designed to detect tick-borne viruses was found sensitive enough to detect even in 1 nanogram quantity of plasmid. A successful mimicking of infection by ticks carrying viruses were observed by PCR and gel electrophoresis. PCR experiments using ticks spiked with plasmids carrying the diagnostic segment specific for each virus were successfully carried out. Hence, the development of primers for detection of viruses causing human disease is significant for future research as well as for rapid detection and analysis in hospitals.