Synthesis of infectious in vitro transcripts from Cassia yellow blotch bromovirus cDNA clones and a reassortment analysis with other bromoviruses in protoplasts

• Published in: Archives of virology Vol. 150; no. 7; pp. 1301 - 1314
• Main Authors: IWAHASHI, F, FUJISAKI, K, KAIDO, M, OKUNO, T, MISE, K
• Format: Journal Article
• Language: English
• Published: Wien Springer 01.07.2005; New York, NY Springer Nature B.V
• Subjects: Arabidopsis thaliana; Barley; Biological and medical sciences; Brome mosaic virus; Bromovirus; Bromovirus - genetics; Bromovirus - pathogenicity; Cassia - virology; Cassia yellow blotch virus; Cloning; Cowpea chlorotic mottle virus; DNA, Complementary - chemical synthesis; Fundamental and applied biological sciences. Psychology; Genome, Viral; Legumes; Microbiology; Miscellaneous; Molecular Sequence Data; Nicotiana benthamiana; Protoplasts - virology; Reassortant Viruses - genetics; Reassortant Viruses - metabolism; RNA, Viral - genetics; Spring beauty latent virus; Transcription, Genetic; Virology; Viruses; Queensland Australia; Australia; Plant pathogen; Virus; Bromovirus; Infection; Plant; Messenger RNA; Leguminosae; Complementary DNA; Dicotyledones; Protoplast; Angiospermae; Cassia; Bromoviridae; Spermatophyta
• DOI: 10.1007/s00705-005-0500-6
• ISSN: 0304-8608

Cassia yellow blotch virus (CYBV), genus Bromovirus, was isolated from the Australian native legume, Cassia pleurocarpa, in western Queensland, and its host range was found to be distinct from other bromoviruses. In this study, CYBV was shown to infect systemically and efficiently a model plant species, Arabidopsis thaliana, as we recently reported for another bromovirus, Spring beauty latent virus (SBLV). We constructed full-length cDNA clones of CYBV genomic RNAs from which infectious in vitro transcripts can be transcribed, and determined their complete nucleotide sequences. CYBV RNA3 contains the box B motif in the intercistronic region, but lacks the subgenomic promoter-like sequence in the 5' noncoding region, as does Brome mosaic virus (BMV). To understand relationships among bromoviruses, we generated reassortants between CYBV and three other bromoviruses, BMV, SBLV and Cowpea chlorotic mottle virus. We found that all reassortants between BMV and CYBV accumulated viral RNAs to detectable levels in protoplasts of Nicotiana benthamiana, even when RNAs 1 and 2, which encode the replication proteins 1a and 2a, respectively, were heterologous. Sequence comparison and reassortment experiments of CYBV and other bromoviruses demonstrated that CYBV is closely related to BMV.