Replication of an Infectious Form of Tobacco Mosaic Virus in Chicken Embryos

Two Cases of Non‐host Resistance against Potyviruses Operating at the Single Cell Level

“…628 BAK et al 1991); and tobacco mosaic wrus (TMV) common strain infected protoplasts of the nonhost cowpea equally as well as the cowpea strain of TMV, which infects and produces symptoms in cowpea (Huber et al, 1981). Indeed, some form of TMV multiplication has been observed in micro-injected chicken embryos (Cochran et al,, 1969) and both TMV and BMV genomic RNAs can replicate in yeast cells (Coutts et al, 1972;Janda and Ahlquist, 1993) suggesting that the requirements for virus multiplication can be rather unspecific. So-called subliminal infection (where virus multiplication in the inoculated leaves is barely discernible because the infection is confined to directly inoculated cells) of nonhost plants has also been demonstrated in a few cases (for TMV in cotton (Cheo, 1970) and TMV in cowpea (Sxilzinski and Zaitlin, 1982)), Furthermore, studies of virus mtitants have shown that viral movement proteins can restrict the virus host range (Ingham and Lazarowitz, 1993;Ingham etal., 1995), Complementation studies have shown that infection with a helper virus can enable another virus, for which the plant is normally a nonhost, to infect and spread within the inoculated leaf (Taliansky et al, 1982;Malyshenko et al, 1989).…”