Screening and Characterization of a New Iflavirus Virus in the Fruit Tree Pest Pyrops candelaria.

Simple Summary: The homopteran insect, Pyrops candelaria (longan lanternfly), mainly harms longan trees, lychees, olives and other crops by absorbing the sap on the trunk. In this study, the reverse etiology method was used to find the pathogens carried by P. candelaria. Through RNA–seq, we found a new iflavirus in P. candelaria, which was first reported in P. candelaria, and we named it PyCaV (Pyrops candelaria associated virus). Identified by a pair of specific primers, it is worth noting that the presence of PyCaV can be identified in the head, chest and abdomen of P. candelaria, and that PyCaV infection rate of P. candelaria is affected by time and location. The above results provide new insights to reveal the role of P. candelaria as a potential vehicle for microbial pathogens and extend our understanding to iflavirus. Pyrops candelaria is one of the common pests of fruit trees, but the research on the pathogenic microorganisms it may carry is very limited. Therefore, it is essential to reveal the pathogenic microbes it carries and their potential hazards. This study found a new virus from the transcriptome of P. candelaria, which was first reported in P. candelaria and named PyCaV (Pyrops candelaria associated virus). RACE and bioinformatics assay revealed that the full length of PyCaV is 10,855 bp with the polyA tail, containing a single open-reading frame (ORF) encoding a polyprotein consisting of 3171 amino acid (aa). The virus has a typical iflavirus structure, including two rhv domains, an RNA helicase domain (HEL), a 3C cysteine protease domain (Pro), and an RNA–dependent RNA polymerase domain (RdRp). Further phylogenetic analysis revealed that this virus belongs to family Iflaviridae and sequence alignments analysis suggested PyCaV is a new member in an unassigned genus of family Iflaviridae. Further in-depth analysis of the virus infection showed that PyCaV is distributed throughout the whole P. candelaria, including its head, chest, and abdomen, but more PyCaV was identified in the chest. The distribution of PyCaV in different parts of P. candelaria was further explored, which showed that more PyCaV was detected in its piercing–sucking mouthparts and chest viscera. Statistical analysis showed that the PyCaV infection was affected by time and location. [ABSTRACT FROM AUTHOR]