Uncovering the mechanisms of potato leaf roll virus’ effect on Myzus persicae’s antiviral immunity

Flaviviruses are single-stranded positive-sense RNA viruses primarily transmitted by arthropods from host to host. Many have caused major global public health crises, including Dengue virus, West Nile virus, and Zika virus. The Myzus persicae Flavivirus is a recently discovered longform aphid flavivirus. Aphids are important virus vectors in plant pathology, and often plant viruses associated with aphid vectors coinfect aphids along with aphid pathogenic viruses. Potato Virus Y (PVY) and potato leaf roll virus (PLRV), both vectored by the green peach aphid (Myzus persicae), are the most widespread and detrimental viruses infecting potatoes. Small interfering RNAs (siRNAs) are short, noncoding RNA molecules involved in RNA interference pathways that can be analyzed using short RNAseq data from an infected host. In this project we analyzed short RNAseq data from healthy aphids and aphids infected with PLRV and PVY, to quantify siRNAs against Flavivirus and Myzus persicae Densovirus. Quality control was performed on sequencing data for the removal of adapter sequences and filtering out rRNA reads. The remaining reads were mapped to reference genomes of known aphid viruses and quantified. This analysis confirmed the effects of viral coinfection, between the circulative plant virus PLRV and aphid pathogenic viruses Densovirus and Flavivirus, on aphid antiviral immunity. These findings may be applied to modulate coinfection of Flaviviruses infecting humans through mosquito vectors. Studying how coinfection alters the RNAi pathway in aphids can lead to therapies which reduce the spread of flavivirus-borne illnesses through RNAi.

As a BTI REU student, I have been exposed to the many research possibilities in the diverse fields of plant sciences. Working in the Heck lab studying plant pathology has opened my eyes to a field I had never thought about pursuing. I have developed significantly as an aspiring researcher by attending weekly research seminars, graduate school information sessions, and the bioinformatics course. I have learned a variety of skills in computational and experimental lab settings, including mapping sequence data, digital droplet PCR, and RNA extraction. I developed my public speaking and science communication skills, through lab presentations and science outreach events. I am so thankful to my mentors, Michael West Ortiz and Douglas Stuehler, and Dr. Heck for their wisdom and guidance throughout the summer. This experience has inspired me to pursue my graduate degree in plant sciences, and I am excited for what is to come.