Virus identification by transcriptome sequencing in mulberry

Morus alba is an economically important deciduous woody plant that is susceptible to a variety of viruses, which can severely impact its quality and yield. However, some viruses with weak virulence and low accumulation have gone unnoticed. In this study, we discovered a new virus, named Quanzhou mulberry virus (QMV), by analyzing transcriptome sequencing data from old mulberry leaves. We identified the complete genome sequence of QMV using transcriptome sequencing and rapid amplification of cDNA ends (RACE). QMV has a genome of 9256 nucleotides (nt), with five putative open reading frames (ORFs), and a regular icosahedral virion. QMV is distributed in the cytoplasm of both N. benthamiana and mulberry, and agroinoculation experiments demonstrate that it can infect N. benthamiana and systematically infect mulberry seedlings without producing noticeable symptoms. Our findings provide a valuable reference for further studies on QMV and related viruses, contributing to the understanding of viral evolution and biodiversity in mulberry.