ARS | Publication request: MAPPING, STRUCTURE AND EVOLUTION OF A HESSIAN FLY-RESPONSIVE GENE, HFR-1, IN WHEAT

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2005
Publication Date: January 15, 2006
Citation: Subramanyam, S., Devos, K.M., Sardesai, N., Nemacheck, J.A., Beales, J., Williams, C.E. 2006. Mapping, structure and evolution of a Hessian fly-responsive gene, Hfr-1, in wheat [abstract]. Plant and Animal Genome Conference. http://www.intl-pag.org.

Technical Abstract: Wheat (Triticum aestivum) plants respond to attack by the highly destructive Hessian fly (Mayetiola destructor) in a gene-for-gene manner. We previously identified a Hessian fly-responsive gene, Hfr-1, in a wheat line “Iris” that was up-regulated during incompatible interactions. We have now determined by southern blotting that there are at least 2 copies of Hfr-1 in Iris. We genetically mapped Hfr-1 to homeologous regions of chromosomes 4A and 7D using a mapping population derived from a cross between “Chinese Spring” and “Synthetic”. One copy of Hfr-1 mapped to the long arm of chromosome 4A flanked by two RFLP markers Xpsr160 and Xpsr490. The other copy mapped to the terminal end of the short arm of chromosome 7D, showing complete linkage with Xpsr946.1. RFLP analysis with nulli-tetrasomic wheat lines verified the chromosomal locations of the Hfr-1 loci. Further, fine mapping using deletion lines of wheat placed copies of Hfr-1 in the 4AL-4 and 7DS-4 terminal deletion bins. Cloning and sequencing of genomic copies of Hfr-1 revealed three introns. The promoter of Hfr-1 was cloned by genome walking and homology search of the PlantCARE database identified several putative cis-acting regulatory elements in the promoter and 5’ UTR region. We have attempted to trace the evolutionary lineage of Hfr-1 by evaluating the presence of the gene in different wild relatives of wheat and other unrelated species. Southern analyses revealed the presence of Hfr-1 in all three genome (A, B and D) donors that are the progenitors of hexaploid wheat, whereas, it was absent in rice and oat.