Metal induction of a Paxillus involutus metallothionein and its heterologous expression in Hebeloma cylindrosporum.
* Metallothioneins are small polypeptides involved in metal tolerance of many eukaryotes. Here we characterized the Pimt1 gene, coding for a metallothionein from the ectomycorrhizal fungus Paxillus involutus. * Expression of Pimt1 in P. involutus under metal stress conditions was measured by northern blot and RT-PCR analyses. The full-length cDNA was used to perform functional complementation in yeast mutant strains and agrotransformation of Hebeloma cylindrosporum. * Heterologous expression in yeast showed that PiMT1 was able to complement the hypersensitivity of mutant strains to cadmium (Cd) and copper (Cu), but not to zinc (Zn). Transcripts were almost undetectable under control conditions, whereas Cu and Cd, but not Zn, strongly induced Pimt1 expression in P. involutus. Constitutive overexpression of Pimt1 in H. cylindrosporum conferred a higher copper tolerance. * The present study identified PiMT1 as a potential determinant in the response of mycorrhizal fungi to Cu and Cd stress. Additionally, we demonstrated the usefulness of mycorrhizal fungi transformation using Agrobacterium technology to approach gene function.
Bellion
Marc
M
Courbot
Mikael
M
Jacob
Christophe
C
Nancy-University, Research Unit 1136 INRA/UHP 'Tree-microbe Interactions', BP 239, F-54506 Vandoeuvre-les-Nancy Cedex, France.
Guinet
Frédéric
F
Nancy-University, Research Unit 1136 INRA/UHP 'Tree-microbe Interactions', BP 239, F-54506 Vandoeuvre-les-Nancy Cedex, France.
Blaudez
Damien
D
Nancy-University, Research Unit 1136 INRA/UHP 'Tree-microbe Interactions', BP 239, F-54506 Vandoeuvre-les-Nancy Cedex, France.
Chalot
Michel
M
Nancy-University, Research Unit 1136 INRA/UHP 'Tree-microbe Interactions', BP 239, F-54506 Vandoeuvre-les-Nancy Cedex, France.
D000363:Agaricales / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001487:Basidiomycota / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005656:Fungal Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005816:Genetic Complementation Test; D008668:Metallothionein / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D008670:Metals / Q000378:metabolism*; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000235:genetics / Q000378:metabolism; D030781:Organisms, Genetically Modified; D012231:Rhizobium / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D014158:Transcription, Genetic; D014170:Transformation, Genetic
D018076:DNA, Complementary; D005656:Fungal Proteins; D008670:Metals; D008668:Metallothionein