title: Advances in the molecular genetic analysis of the flax-flax rust interaction.
abstract: The L6 and M rust-resistance genes, representing two of the five rust-resistance gene loci in flax (Linum usitatissimum), have been cloned. The molecular data are fully consistent with earlier genetic data: the L locus is a single gene with multiple alleles expressing different rust resistance specificities, and the M locus is complex, containing an array of about 15 similar genes. Thus, while L6 and M resistance genes have 86% nucleotide identity, their locus structure is very different. These genes encode products belonging to the nucleotide binding site-leucine-rich repeat class of disease-resistance proteins. Analysis of alleles from the L locus and chimeric genes is providing evidence suggesting that important specificity determinants occur in the C-terminal half of the proteins, the region containing the leucine-rich repeats. The isolation and characterization of the rust (Melampsora lini) avirulence genes that correspond to the cloned rust-resistance genes is one of the major challenges remaining to the understanding of this system.
authors.affiliation: CSIRO Plant Industry, GPO Box 1600, Canberra, ACT, 2601, Australia. ellisj@pican.pi.csiro.au
authors.forename: J
authors.initials: J
authors.lastname: Ellis
authors.forename: G
authors.initials: G
authors.lastname: Lawrence
authors.forename: M
authors.initials: M
authors.lastname: Ayliffe
authors.forename: P
authors.initials: P
authors.lastname: Anderson
authors.forename: N
authors.initials: N
authors.lastname: Collins
authors.forename: J
authors.initials: J
authors.lastname: Finnegan
authors.forename: D
authors.initials: D
authors.lastname: Frost
authors.forename: J
authors.initials: J
authors.lastname: Luck
authors.forename: T
authors.initials: T
authors.lastname: Pryor