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Divergence in gene expression related to variation in host specificity of an ectomycorrhizal fungus

Le Quéré, Antoine LU ; Schutzendubel, Andres LU ; Rajashekar, Balaji LU ; Canbäck, Björn LU ; Hedh, Jenny LU ; Erland, Susanne LU ; Johansson, Tomas LU and Tunlid, Anders LU (2004) In Molecular Ecology 13(12). p.3809-3819
Abstract
Ectomycorrhizae are formed by mutualistic interactions between fungi and the roots of woody plants. During symbiosis the two organisms exchange carbon and nutrients in a specific tissue that is formed at the contact between a compatible fungus and plant. There is considerable variation in the degree of host specificity among species and strains of ectomycorrhizal fungi. In this study, we have for the first time shown that this variation is associated with quantitative differences in gene expression, and with divergence in nucleotide sequences of symbiosis-regulated genes. Gene expression and sequence evolution were compared in different strains of the ectomycorrhizal fungus Paxillus involutus; the strains included Nau, which is not... (More)
Ectomycorrhizae are formed by mutualistic interactions between fungi and the roots of woody plants. During symbiosis the two organisms exchange carbon and nutrients in a specific tissue that is formed at the contact between a compatible fungus and plant. There is considerable variation in the degree of host specificity among species and strains of ectomycorrhizal fungi. In this study, we have for the first time shown that this variation is associated with quantitative differences in gene expression, and with divergence in nucleotide sequences of symbiosis-regulated genes. Gene expression and sequence evolution were compared in different strains of the ectomycorrhizal fungus Paxillus involutus; the strains included Nau, which is not compatible with birch and poplar, and the two compatible strains Maj and ATCC200175. On a genomic level, Nau and Maj were very similar. The sequence identity was 98.9% in the 16 loci analysed, and only three out of 1075 genes analysed by microarray-based hybridizations had signals indicating differences in gene copy numbers. In contrast, 66 out of the 1075 genes were differentially expressed in Maj compared to Nau after contact with birch roots. Thirty-seven of these symbiosis-regulated genes were also differentially expressed in the ATCC strain. Comparative analysis of DNA sequences of the symbiosis-regulated genes in different strains showed that two of them have evolved at an enhanced rate in Nau. The sequence divergence can be explained by a decreased selection pressure, which in turn is determined by lower functional constraints on these proteins in Nau as compared to the compatible strains. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Molecular Ecology
volume
13
issue
12
pages
3809 - 3819
publisher
Wiley-Blackwell
external identifiers
  • wos:000225150000016
  • pmid:15548293
  • scopus:9644254159
ISSN
0962-1083
DOI
10.1111/j.1365-294X.2004.02369.x
language
English
LU publication?
yes
id
878a77da-fd73-42a7-8add-532934a6097d (old id 135578)
date added to LUP
2007-06-29 12:08:27
date last changed
2017-11-19 03:32:34
@article{878a77da-fd73-42a7-8add-532934a6097d,
  abstract     = {Ectomycorrhizae are formed by mutualistic interactions between fungi and the roots of woody plants. During symbiosis the two organisms exchange carbon and nutrients in a specific tissue that is formed at the contact between a compatible fungus and plant. There is considerable variation in the degree of host specificity among species and strains of ectomycorrhizal fungi. In this study, we have for the first time shown that this variation is associated with quantitative differences in gene expression, and with divergence in nucleotide sequences of symbiosis-regulated genes. Gene expression and sequence evolution were compared in different strains of the ectomycorrhizal fungus Paxillus involutus; the strains included Nau, which is not compatible with birch and poplar, and the two compatible strains Maj and ATCC200175. On a genomic level, Nau and Maj were very similar. The sequence identity was 98.9% in the 16 loci analysed, and only three out of 1075 genes analysed by microarray-based hybridizations had signals indicating differences in gene copy numbers. In contrast, 66 out of the 1075 genes were differentially expressed in Maj compared to Nau after contact with birch roots. Thirty-seven of these symbiosis-regulated genes were also differentially expressed in the ATCC strain. Comparative analysis of DNA sequences of the symbiosis-regulated genes in different strains showed that two of them have evolved at an enhanced rate in Nau. The sequence divergence can be explained by a decreased selection pressure, which in turn is determined by lower functional constraints on these proteins in Nau as compared to the compatible strains.},
  author       = {Le Quéré, Antoine and Schutzendubel, Andres and Rajashekar, Balaji and Canbäck, Björn and Hedh, Jenny and Erland, Susanne and Johansson, Tomas and Tunlid, Anders},
  issn         = {0962-1083},
  language     = {eng},
  number       = {12},
  pages        = {3809--3819},
  publisher    = {Wiley-Blackwell},
  series       = {Molecular Ecology},
  title        = {Divergence in gene expression related to variation in host specificity of an ectomycorrhizal fungus},
  url          = {http://dx.doi.org/10.1111/j.1365-294X.2004.02369.x},
  volume       = {13},
  year         = {2004},
}