A multidirectional non-cell autonomous control and a genetic interaction restricting tobacco etch virus susceptibility in Arabidopsis.
BACKGROUND
Viruses constitute a major class of pathogens that infect a variety of hosts. Understanding the intricacies of signaling during host-virus interactions should aid in designing disease prevention strategies and in understanding mechanistic aspects of host and pathogen signaling machinery.


RESULTS
An Arabidopsis mutant, B149, impaired in susceptibility to Tobacco etch virus (TEV), a positive strand RNA virus of picoRNA family, was identified using a high-throughput genetic screen and a counterselection scheme. The defects include initiation of infection foci, rate of cell-to-cell movement and long distance movement.


CONCLUSIONS
The defect in infectivity is conferred by a recessive locus. Molecular genetic analysis and complementation analysis with three alleles of a previously published mutant lsp1 (loss of susceptibility to potyviruses) indicate a genetic interaction conferring haploinsufficiency between the B149 locus and certain alleles of lsp1 resulting in impaired host susceptibility. The pattern of restriction of TEV foci on leaves at or near the boundaries of certain cell types and leaf boundaries suggest dysregulation of a multidirectional non-cell autonomous regulatory mechanism. Understanding the nature of this multidirectional signal and the molecular genetic mechanism conferring it should potentially reveal a novel arsenal in the cellular machinery.
Gopalan
Suresh
S
Institute of Biological Chemistry, Washington State University, Pullman, Washington, United States of America. gopalans2@hotmail.com
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D005808:Genes, Recessive; D020022:Genetic Predisposition to Disease; D005821:Genetic Techniques; D008954:Models, Biological; D008957:Models, Genetic; D009154:Mutation; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics*; D018521:Plant Physiological Phenomena; D017800:Potyvirus / Q000378:metabolism*
D029681:Arabidopsis Proteins