The rate of cell-to-cell movement in squash of cucumber mosaic virus is affected by sequences of the capsid protein

The M strain of cucumber mosaic virus (CMV) does not infect squash plants s ystemically and moves very slowly in inoculated cotyledons. Systemic infect ion and an increase in the rate of local movement were observed when amino acids 129 or 214 of the M-CMV capsid protein (CP) were altered to those pre sent in the Fny strain of CMV. While the opposite alterations to the CP of Fny-CMV inhibited systemic infection of squash, they did not show the same effects on the rates of both cell-to-cell and long-distance movement. Howev er, the ability of CMV to infect squash systemically was affected by the ra te of cell-to-cell movement.