Different forms of interference between two tobamoviruses in two different hosts

Abstract

Oilseed rape mosaic (ORMV) and tobacco mild green mosaic (TMGMV) tobamoviruses interfered with each other when infecting the same host, and interference was host-dependent. In tobacco cross-protection was obtained in two ways: the protecting virus prevented the accumulation of the challenging virus, even in the inoculated leaf; in Arabidopsis, protection was obtained only when the protecting virus was TMGMV. The protecting mechanism in Arabidopsis appeared to differ from that operating in tobacco. Although ORMV could be detected in the inoculated leaf, TMGMV prevented systemic infection by ORMV. Thus the host appears to play an important role in this type of cross-protection.