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Compatible and Incompetent Paxillus involutus Isolates for Ectomycorrhiza Formation in vitro with Poplar (Populus × canescens) Differ in H 2 O 2 Production
Author(s) -
Gafur A.,
Schützendübel A.,
LangenfeldHeyser R.,
Fritz E.,
Polle A.
Publication year - 2004
Publication title -
plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 1435-8603
DOI - 10.1055/s-2003-44718
Subject(s) - paxillus involutus , biology , ectomycorrhiza , botany , hypha , mycorrhiza , axenic , symbiosis , bacteria , genetics
Abstract: Isolates of Paxillus involutus (Batsch) Fr. collected from different hosts and environmental conditions were screened for their ability to form ectomycorrhizal symbiosis with hybrid poplar P. × canescens ( = Populus tremula L. × P. alba) in vitro. The ability to form ectomycorrhiza varied between the fungal isolates and was not correlated with the growth rate of the fungi on agar‐based medium. The isolate MAJ, which was capable of mycorrhiza synthesis under axenic conditions, and the incompetent isolate NAU were characterized morphologically and anatomically. MAJ formed a typical hyphal mantle and a Hartig net, whereas NAU was not able to penetrate the host cell walls and caused thickenings of the outer cell walls of the host. MAJ, but not NAU, displayed strong H 2 O 2 accumulation in the outer hyphal mantle. Increases in H 2 O 2 in the outer epidermal walls and adjacent hyphae of the incompetent isolate were moderate. No increases of H 2 O 2 in response to the mycobionts were found inside roots. Suggested functions of H 2 O 2 production in the outer hyphal mantle of the compatible interaction are: growth regulation of the host's roots, defence against other invading microbes, or increasing plant‐innate immunity. The system established here for P. × canescens compatible and incompetent fungal associations will be useful to take advantage of genomic information now available for poplar to study tree‐fungal interactions at the molecular and physiological level.