Infectivity and complete nucleotide sequence of cucumber fruit mottle mosaic virus isolate Cm cDNA

Three isolates of cucumber fruit mottle mosaic virus (CFMMV) were collected from melon, cucumber, and pumpkin plants in Korea. A full-length cDNA clone of CFMMV-Cm (melon isolate) was produced and evaluated for infectivity after T7 transcription in vitro (pT7CF-Cmflc). The complete CFMMV genome sequence of the infectious clone pT7CF-Cmflc was determined. The genome of CFMMV-Cm consisted of 6,571 nucleotides and shared high nucleotide sequence identity (98.8 %) with the Israel isolate of CFMMV. Based on the infectious clone pT7CF-Cmflc, a CaMV 35S-promoter driven cDNA clone (p35SCF-Cmflc) was subsequently constructed and sequenced. Mechanical inoculation with RNA transcripts of pT7CF-Cmflc and agro-inoculation with p35SCF-Cmflc resulted in systemic infection of cucumber and melon, producing symptoms similar to those produced by CFMMV-Cm. Progeny virus in infected plants was detected by RT-PCR, western blot assay, and transmission electron microscopy.