Inhibition of brome mosaic virus (BMV) amplification in protoplasts from transgenic tobacco plants expressing replicable BMV RNAs

• Published in: Journal of general virology Vol. 76; no. 11; pp. 2827 - 2833
• Main Authors: Kaido, Masanori, Mori, Masashi, Mise, Kazuyuki, Okuno, Tetsuro, Furusawa, Iwao
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01-11-1995
• Subjects: brome mosaic virus; Bromovirus - genetics; Bromovirus - pathogenicity; Bromovirus - physiology; cauliflower mosaic virus; Cucumovirus - pathogenicity; Gene Amplification; Nicotiana - metabolism; Nicotiana - virology; Nicotiana tabacum; Plants, Genetically Modified - metabolism; Plants, Genetically Modified - virology; Plants, Toxic; Protoplasts - metabolism; Protoplasts - virology; RNA, Viral - metabolism; Virus Replication
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-76-11-2827

Laboratory of Plant Pathology, Faculty of Agriculture, Kyoto University, Sakyoku, Kyoto 606-01, Japan
Transgenic tobacco plants (V123 plants) expressing a set of full-length brome mosaic virus (BMV) genomic RNAs from the cauliflower mosaic virus 35S promoter were produced. The accumulation level of BMV RNAs in V123 plant cells was approximately 1% of that in non-transgenic tobacco protoplasts inoculated with BMV RNAs. The level of BMV RNA in V123 protoplasts did not increase after inoculating the protoplasts with BMV RNAs, whereas V123 protoplasts supported the accumulation of cucumber mosaic virus (CMV) RNAs to a level similar to that in non-transgenic tobacco protoplasts after inoculation with CMV RNA. Such BMV-specific resistance was also observed in protoplasts from V12 plants expressing full-length BMV RNA1 and RNA2, both of which are required and sufficient for BMV RNA replication. On the other hand, protoplasts from M12 plants, expressing truncated BMV RNA1 and RNA2 in which the 3' 200 nucleotides required for BMV RNA replication were deleted, exhibited weaker resistance to infection with BMV RNA than V12 protoplasts, although the accumulation level of truncated BMV RNA1 and RNA2 in M12 protoplasts was higher than that of BMV RNA1 and RNA2 and V12 protoplasts. These results suggest that expression of BMV RNA replicons is involved in the induction of resistance, rather than high-level accumulation of BMV RNAs and/or their encoded proteins.
* Author for correspondence. Fax + 81 75 753 6146.
Received 16 May 1995;
accepted 28 June 1995.