Faculty Advisor or Committee Member

Kristin K. Wobbe, Advisor

Faculty Advisor or Committee Member

Craig D. Fairchild, Committee Member

Faculty Advisor or Committee Member

William D. Hobey, Committee Member




TCV (Turnip crinkle virus) coat protein is required for the resistance response in Arabidopsis thaliana Di-17 plants. An aspartate to asparagine mutation at amino acid four of the coat protein is sufficient to result in resistance-breaking. To determine the essential chemical properties responsible for the induction of resistance, a series of site-directed mutants were produced. Serine as well as asparagine at amino acid four induces systemic disease on both Di-3 and Di-17 plants; however, replacement of aspartate with glutamate retains the ability to induce the HR (hypersensitive response) and resist TCV infection with rapid and strong induction of PR-1 gene. These data suggest that the negative charge at the fourth amino acid of the coat protein is critical for the induction of resistance. Taken together with other mutagenesis research, the N-terminus of the coat protein appears to be the sole viral recognition element. The A. thaliana TIP protein is suggested to be involved in resistance, mainly through its C-terminus. Interestingly, one of the resistance-breaking mutants (D4N) produces a HR on Di-3 plants that are normally susceptible. The Di-3 TIP protein has several differences from the Di-17 TIP. To detect whether the delayed HR is related to interaction between Di-3 TIP and D4N mutation, a yeast two-hybrid assay was attempted. Interactions have not yet been detected. There are a number of possible explanations.


Worcester Polytechnic Institute

Degree Name



Chemistry & Biochemistry

Project Type


Date Accepted





protein interaction, coat protein, resistance, arabidopsis, turnip crinkle virus, Plants, Virus resistance, Plant-pathogen relationships, Genetic aspects, Arabidopsis thaliana, Turnip crinkle virus