9421002 Howell The goal of this project is to identify genes responsible for the role of the host in the movement of cauliflower mosaic virus (CaMV) and in the process to find plant genes that confer virus resistance. Two approaches are proposed. 1)Virus resistance mutants of Arabidopsis will be isolated and characterized and 2)Arabidopsis suppresser mutants susceptible to defective plant viruses will be selected. The second approach is novel in that it allows positive selection for susceptible plants that suppress mutations in any chosen viral gene or in any particular function of a given gene. If successful, it will open new avenues for the selection of genes important in plant disease resistance. %%% This proposal describes a novel approach to the study of plant-virus interactions and the identification of host functions involved in virus replication and movement in plants. Arabidopsis plants that are susceptible to infection by defective CaMV will be selected. Because the interplay between host and virus is most apparent in virus movement, mutations that disable the CaMV movement protein will be created. In addition, virus resistant mutants will be selected and a virus-resistant trait, apparently a one-gene trait, which has been shown to block long-distance virus movement will be characterized. ***
