Submitted to: The Plant Cell
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 7, 1996
Publication Date: N/A
Interpretive Summary: Tobacco ringspot virus (TRSV) infests many plants and often 100% of seeds are infected. We studied the tolerance to TRSV infection in Arabidopsis. The tolerant plants showed no signs of infection while the sensitive plants became necrotic. Both the tolerant and sensitive plants had the virus. We found the gene that was affected. Since plants pass on the resistance, our rfindings may aid isolation and characterization of TRSV tolerance gene(s) from soybean and other agronomic crops and may provide an excellent model system for the genetic and molecular analysis of tolerance to a plant virus.
Technical Abstract: All 97 Arabidopsis ecotypes tested were susceptible when inoculated with tobacco ringspot virus (TRSV). The most sensitive plants died 10 days after inoculation while the most tolerant ecotypes were either symptomless or developed mild symptoms. Four ecotypes were selected for further study based on their differential reactions to TRSV. Infected plants of ecotypes Col-0 and Col-0 gl1 flowered and produced seeds like non-infected plants, while those of ecotyes Estland and H55 died and failed to produce seeds. Symptoms appeared on sensitive plants approximately 5 to 6 days after inoculation with the grape strain of TRSV. Serological studies indicated that the virus accumulated at essentially the same rates and to the same levels in the four ecotypes, demonstrating that differences in symptom development were not due to a suppression of virus accumulation. Seed transmission frequency of TRSV in Arabidopsis was 97% for ecotypes Col-0 143 and Col-0 gl1. Genetic studies of these four ecotypes indicated that tolerance was due to a single incompletely dominant locus. Using SSLP and CAPS markers, the tolerance locus (reserved symbol is TTR) has been mapped to chromosome V near the nga129 marker. The identification of tolerance and sensitive interactions between TRSV and A. thaliana ecotypes provides an excellent model system for the genetic and molecular analysis of tolerance to a plant virus.