Skip to Main content Skip to Navigation
Theses

Caractérisation par ingénierie génomique des profils d'expression génique de Pisolithus tinctorius et d'Eucalyptus globulus au cours du développement de la symbiose ectomycorhizienne

Abstract : Ectomycorrhiza formation and function alter both fungal and plant gene expression. The identification of a large rumber of novel genes expressed exclusively or predominantly in the symbiosis will contribute greatly to the understanding of the function of the ectomycorrhizal association. We have constructed a cDNA library of 4-day-old Eucalyphls globulus-Pisolithus tinctorius ectomycorrhiza by random cloning and through suppression subtractive hybridization. We screened 715 arrayed cDNAs to identify symbiosis-regulated genes by using differential hybridization. Gene expression profiles obtained from free-living Pisolithus tinctorius, non-inoculated roots and ectomycorrhizas at various developmental stages, from the earliest contacts (4 days) to the functionning symbiotic organ (28 days) were analyzed. Comparisons of free-living partners and symbiotic tissues revealed significant changes in the expression levels (differential expression ratio> 2.0) for 11 to 23% of the genes analyzed at the different stages of mycorrhiza formation. No ectomycorrhiza-specific gene was detected. We derived groups of coordinately expressed genes (i.e. regulons) using hierarchical clustering and Self Organizing Maps. At least a dozen of distinct temporal patterns of induction/repression were observed. The main fungal regulons contained genes coding for cell-wall and membrane proteins, communication genes, and metallothionein-related poteins. In the host root, a major down-regulated regulon comprised genes involved in water transport and stress suggesting that mycorrhiza development improves water uptake.We have furthermore characterized cDNA clones corresponding to Pisolithus signalling genes (ras, raf and calcineurine) and to a new hydrophobin gene (HydPt-3).
Document type :
Theses
Complete list of metadatas

https://hal.univ-lorraine.fr/tel-01748571
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 11:41:28 AM
Last modification on : Thursday, January 7, 2021 - 3:40:27 PM
Long-term archiving on: : Friday, September 14, 2018 - 9:01:57 AM

File

SCD_T_2001_0019_DUPLESSIS.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01748571, version 1

Collections

Citation

Sébastien Duplessis. Caractérisation par ingénierie génomique des profils d'expression génique de Pisolithus tinctorius et d'Eucalyptus globulus au cours du développement de la symbiose ectomycorhizienne. Biologie végétale. Université Henri Poincaré - Nancy 1, 2001. Français. ⟨NNT : 2001NAN10019⟩. ⟨tel-01748571⟩

Share

Metrics

Record views

81

Files downloads

312