Identification of root-knot nematode genetic loci that modulate distinct patterns of host gene expression using a genetic/genomic approach
V. WILLIAMSON (1), D. Nielsen (2), D. Bird (2) (1) Univ. of California Davis, U.S.A.; (2) North Carolina State University, U.S.A.

The root-knot nematode Meloidogyne hapla can reproduce on a wide range of plant species and can cause considerable agricultural damage. These pests have a complex, biotrophic interaction with their hosts that continues for over a month and includes morphological changes in both the host and the pathogen. Wild isolates of M. hapla display phenotypic differences germane to the host-parasite interaction. For example, strains LM and VW9, originally isolated in France and California, respectively, differ in ability to reproduce on the nematode resistant common bean cultivar NemaSnap. The 50Mb genome sequences of both nematode strains have been determined. We have carried out genetic crosses between LM and VW9 individuals and produced a genetic map based on SNPs in F2 lines. Due to the unusual reproductive mode, F2 lines resemble recombinant inbred lines and can be maintained as greenhouse cultures. RNAseq analysis of galled tissue of Medicago truncatula infected with each of 98 F2 lines was collected and analyzed for cross-species gene expression interactions. QTL analysis revealed 218 plant genes whose expression levels were influenced by the allele present at one or more parasite loci. A small number of nematode loci influenced expression of a large number of plant genes. Most dramatic was a set of host MADS-box transcription factors that were strongly influenced by the allele present at a locus that has been localized to an 87 kb region of the nematode genome.

Abstract Number: P11-383
Session Type: Poster