Molecular and Genomic Characterization of Novel Mycovirus from Botrytis cinerea (Kst32B)

Abstract

Botrytis cinerea is responsible for causing grey mold disease in more than 200 plant species. B.cinerea is difficult to control because of different forms of infection, diverse host range, and survival as mycelia for a longer period of time. Mycoviruses belonging to different families have been identified in B.cinerea. This study aims to identify hypovirulent mycoviruses from B.cinerea isolate Kst32B that can be used as a biocontrol agent against grey mold disease. In this study, Next Generation Sequencing (NGS) of isolate Kst32B revealed the presence of five mycoviruses. The presence of each mycovirus was confirmed using virus-specific primers by RT-PCR and followed by genomic characterization using bioinformatic analysis. The first mycovirus identified was dsRNA Botrytis cinerea victorivirus 1 (BcVV1a). It was 5205bp long encoding two overlapping open reading frames (ORF). ORF 1 encodes coat protein while ORF2 encodes RNA-dependent RNA polymerase (RdRp). The second virus identified was (+)ssRNA Botrytis cinerea Umbra-like Virus 3 (BcUlV3). The complete genome sequence of BcUlV3 was 3624bp. The BcUlV3 genome consists of two noncontiguous ORFs. The ORF1 encodes hypothetical protein while ORF2 encodes RdRp. The third mycovirus identified was (+)ssRNA Botrytis cinerea orfanplasmovirus 1 (BcORFPlV1). The complete genome sequence of BcORFPlV1 was 3102bp and encodes a single large ORF encoding RdRp. Further research based on the biological characterization of these mycoviruses will help to understand their impact on the fitness of host fungus.