Molecular Characterization and Infectious Assay of Cymbidium Mosaic Virus in the Medicinal Plant Tetrastigma hemsleyanum in China

Abstract

Tetrastigma hemsleyanum is a valuable and rare medicinal herb in the family Vitaceae . With its large‐scale cultivation in China, a virus‐like disease has emerged threatening both yield and quality in recent years. However, the viral pathogen has not been reported. Here, we detected a new isolate of Cymbidium mosaic virus (CymMV‐TH) through high‐throughput sequencing by Illumina and reverse transcription‐PCR. Molecular detection and inoculation assays showed that T. hemsleyanum and Nicotiana benthamiana plants were susceptible to this viral isolate. A full‐length cDNA clone of CymMV‐TH driven by the CaMV 35S promoter was generated using one‐step In‐Fusion cloning. Both agroinfiltration and mechanical inoculation demonstrated that CymMV‐TH induced mosaic symptoms on T. hemsleyanum leaves similar to those observed in naturally infected plants grown in the field. These findings highlight the need to establish surveillance and disease management programmes to monitor and limit the spread of this virus in T. hemsleyanum production fields.