Publication

Identification of quantitiative trait loci affecting ectomycorrhizal symbiosis in an interspecific F1 poplar cross and differentail expression of genes in ectomycorrhizas of the two parents: Populus deltoides and Populus trichocarpa. Public

Jessy Labbé,Véronique Jorge,Annegret Kohler,Patrice Vion,Benoît Marçais,Catherine Bastien,Gerald A. Tuskan,Francis Martin,François Le Tacon 2011 June 01 Tree Genetics & Genomes Volume 7, Issue 3 , pp 617-627
Download Publication: 10.1007_s11295-010-0361-3

Abstract

A Populus deltoides€‰ x €‰Populus trichocarpa F1 pedigree was analyzed for quantitative trait loci (QTLs) affecting ectomycorrhizal development and for microarray characterization of gene networks involved in this symbiosis. A 300 genotype progeny set was evaluated for its ability to form ectomycorrhiza with the basidiomycete Laccaria bicolor. The percentage of mycorrhizal root tips was determined on the root systems of all 300 progeny and their two parents. QTL analysis identified four significant QTLs, one on the P. deltoides and three on the P. trichocarpa genetic maps. These QTLs were aligned to the P. trichocarpa genome and each contained several megabases and encompass numerous genes. NimbleGen whole-genome microarray, using cDNA from RNA extracts of ectomycorrhizal root tips from the parental genotypes P. trichocarpa and P. deltoides, was used to narrow the candidate gene list. Among the 1,543 differentially expressed genes (p value ≤ 0.05; ≥5.0-fold change in transcript level) having different transcript levels in mycorrhiza of the two parents, 41 transcripts were located in the QTL intervals: 20 in Myc_d1, 14 in Myc_t1, and seven in Myc_t2, while no significant differences among transcripts were found in Myc_t3. Among these 41 transcripts, 25 were overrepresented in P. deltoides relative to P. trichocarpa; 16 were overrepresented in P. trichocarpa. The transcript showing the highest overrepresentation in P. trichocarpa mycorrhiza libraries compared to P. deltoides mycorrhiza codes for an ethylene-sensitive EREBP-4 protein which may repress defense mechanisms in P. trichocarpa while the highest overrepresented transcripts in P. deltoides code for proteins/genes typically associated with pathogen resistance.

Highlights


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Fig. 1
Distribution of Populus deltoides (female) and Populus trichocarpa (male) and their F1 progeny following their root colonization by Laccaria bicolor. The bars represent the number of genotypes distributed in each class according to their percentages of mycorrhizal colonization. The percentage of P. deltoides is identified by the pink line while that of P. trichocarpa is identified by the blue line.

Citation

Jessy Labbé, Véronique Jorge, Annegret Kohler, Patrice Vion, Benoît Marçais, Catherine Bastien, Gerald A. Tuskan, Francis Martin and François Le Tacon; Identification of quantitiative trait loci affecting ectomycorrhizal symbiosis in an interspecific F1 poplar cross and differentail expression of genes in ectomycorrhizas of the two parents: Populus deltoides and Populus trichocarpa.Tree Genetics & Genomes Volume 7, Issue 3 , pp 617-627


Comments

published online 11 January 2011