Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/15/2006
Publication Date: 1/14/2007
Citation: Lu, H., Fellers, J.P., Tai, Y., Meinhardt, S.W., Friesen, T.L., Faris, J.D. 2007. Delineation of the wheat Tsn1 candidate gene region. Plant and Animal Genome VX Conference Abstracts. p. 174.
Technical Abstract: The wheat Tsn1 gene confers sensitivity to the host-selective proteinaceous toxins Ptr ToxA and SnToxA produced by the pathogenic fungi Pyrenophora tritici-repentis and Stagonospora nodorum, respectively. A positional cloning strategy is being used to clone this gene. An F2 population consisting of 5,438 gametes was developed for high-resolution mapping. Multiple chromosome walking steps in conjunction with complete sequencing of BACs identified in the Langdon durum BAC library were performed. A total of 14 BACs were sequenced and assembled into two contigs that together spanned more than 1 Mb. Mapping results indicated that one contig spanned the Tsn1 gene. The Tsn1 candidate region is about 400 kb in size and contains more than ten putative genes. Three of the putative genes have been disproved to be Tsn1 by comparative sequence analysis of Langdon EMS-induced Tsn1-disrupted mutants with the wild type and by virus-induced gene silencing (VIGS). We are continuing the systematic testing of the remaining candidates to determine which candidate is Tsn1. The isolation of Tsn1 will allow us to begin deciphering the molecular interactions and mechanisms associated with the wheat-P. tritici-repentis and wheat-S. nodorum pathosystems.