High-level molecular diversity of copper-zinc superoxide dismutase genes among and within species of arbuscular Mycorrhizal fungi.

Details

Ressource 1Download: BIB_89FB34773479.P001.pdf (197.17 [Ko])
State: Public
Version: author
Serval ID
serval:BIB_89FB34773479
Type
Article: article from journal or magazin.
Collection
Publications
Title
High-level molecular diversity of copper-zinc superoxide dismutase genes among and within species of arbuscular Mycorrhizal fungi.
Journal
Applied and Environmental Microbiology
Author(s)
Corradi N., Ruffner B., Croll D., Colard A., Horák A., Sanders I.R.
ISSN
1098-5336[electronic], 0099-2240[linking]
Publication state
Published
Issued date
2009
Peer-reviewed
Oui
Volume
75
Number
7
Pages
1970-1978
Language
english
Abstract
In the ecologically important arbuscular mycorrhizal fungi (AMF), Sod1 encodes a functional polypeptide that confers increased tolerance to oxidative stress and that is upregulated inside the roots during early steps of the symbiosis with host plants. It is still unclear whether its expression is directed at scavenging reactive oxygen species (ROS) produced by the host, if it plays a role in the fungus-host dialogue, or if it is a consequence of oxidative stress from the surrounding environment. All these possibilities are equally likely, and molecular variation at the Sod1 locus can possibly have adaptive implications for one or all of the three mentioned functions. In this paper, we analyzed the diversity of the Sod1 gene in six AMF species, as well as 14 Glomus intraradices isolates from a single natural population. By sequencing this locus, we identified a large amount of nucleotide and amino acid molecular diversity both among AMF species and individuals, suggesting a rapid divergence of its codons. The Sod1 gene was monomorphic within each isolate we analyzed, and quantitative PCR strongly suggest this locus is present as a single copy in G. intraradices. Maximum-likelihood analyses performed using a variety of models for codon evolution indicated that a number of amino acid sites most likely evolved under the regime of positive selection among AMF species. In addition, we found that some isolates of G. intraradices from a natural population harbor very divergent orthologous Sod1 sequences, and our analysis suggested that diversifying selection, rather than recombination, was responsible for the persistence of this molecular diversity within the AMF population.
Keywords
DNA, Fungal/chemistry, DNA, Fungal/genetics, Evolution, Molecular, Fungi/enzymology, Fungi/genetics, Molecular Sequence Data, Mycorrhizae/enzymology, Mycorrhizae/genetics, Phylogeny, Polymorphism, Genetic, Selection, Genetic, Sequence Analysis, DNA, Sequence Homology, Amino Acid, Superoxide Dismutase/genetics
Pubmed
Web of science
Open Access
Yes
Create date
05/01/2009 10:32
Last modification date
20/08/2019 14:48
Usage data