AnArabidopsis thalianaMutant with Virus-Inducible Phenotype

Abstract

The role of host factors in plant viral diseases is not well understood. To study this important aspect of plant–pathogen interaction, we identified anArabidopsis thalianamutant, designatedvid1(virus-inducibledwarf), with altered responses to viral infection. Specifically,vid1resembled the wild-type plants when healthy but developed a severely dwarfed phenotype with a loss of apical dominance following infection by a tobamovirus. Genetic segregation showed that thevid1phenotype is caused by a recessive mutation in a single gene. Since systemic viral infection is thought to interfere with the host plant intercellular transport, we propose that thevid1mutation affects this transport process. Combination of the mutation and viral infection may disrupt transport of developmental regulators, such as hormones, causing formation of thevid1phenotype. Indeed, the effect ofvid1mutation was repressed by exogenous application of a plant hormone auxin. Potentially, thevid1mutant will help characterize the mechanism of virus–plant interaction and formation of plant viral disease symptoms.