Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 20, 1996
Publication Date: N/A
Technical Abstract: Using Arabidopsis thaliana as a model for the study of tolerance to viral diseases, we identified a locus named TTR1 which confers tolerance to tobacco ringspot virus (TRSV) infection. The virus accumulated to the same level and at the same rate in both the tolerant ecotype, Columbia, and the sensitive ecotype, Estland. Columbia does not develop symptoms while Estland turns chlorotic and dies following infection. Genetic studies indicate that tolerance is incompletely dominant over sensitivity. Infected heterozygotes are intermediate, displaying chlorosis and producing seeds at a reduced level. Because of the incomplete dominance, it is not clear whether tolerance or sensitivity is the active function. Initial mapping of the locus using more than 400 F3 families indicated that the locus is located between markers DFR and ngal 29 with genetic distances of 5.7 cM and 6.3 cM, respectively. The locus has now been more precisely mapped using informative F3 families and RFLP probes derived from the left ends of yeast artificial chromosome (YAC) clones in the region of TTR1. TTR1 was located to the interval between CIC2A12LE and yUP18A5LE, with genetic distances of 0.62 cM and 0.23 cM respectively. Our efforts to further define the physical structure of the TTR1 locus will be presented.