Paxillus involutus mycorrhiza attenuate NaCl-stress responses in the salt-sensitive hybrid poplar Populusxcanescens
Autor: | Rosemarie Langenfeld-Heyser, Andrea Polle, C. F. Lu, Eberhard Fritz, Tanja Dučić, J. Gao, Abdul Gafur, Ph. Tachd |
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Rok vydání: | 2006 |
Předmět: |
0106 biological sciences
Plant Science Sodium Chloride 01 natural sciences Plant Roots Antioxidants 03 medical and health sciences Salicaceae Microscopy Electron Transmission Cations Botany Genetics Paxillus involutus Biomass Mycorrhiza Molecular Biology Ecology Evolution Behavior and Systematics 030304 developmental biology 0303 health sciences Hartig net biology Basidiomycota fungi Xylem food and beverages General Medicine Hydrogen Peroxide Ectomycorrhiza Oxidative stress Salinity Poplar hybrid Subcellular element localisation biology.organism_classification Populus × canescens Oxidative Stress Populus Reactive Oxygen Species 010606 plant biology & botany |
Zdroj: | Mycorrhiza. 17(2) |
ISSN: | 0940-6360 |
Popis: | In order to characterise the effect of ectomycorrhiza on Na+-responses of the salt-sensitive poplar hybrid Populus x canescens, growth and stress responses of Paxillus involutus (strain MAJ) were tested in liquid cultures in the presence of 20 to 500 mM NaCl, and the effects of mycorrhization on mineral nutrient accumulation and oxidative stress were characterised in mycorrhizal and non-mycorrhizal poplar seedlings exposed to 150 mM NaCl. Paxillus involutus was salt tolerant, showing biomass increases in media containing up to 500 mM NaCl after 4 weeks growth. Mycorrhizal mantle formation on poplar roots was not affected by 150 mM NaCl. Whole plant performance was positively affected by the fungus because total biomass was greater and leaves accumulated less Na+ than non-mycorrhizal plants. Energy dispersive X-ray microanalysis using transmission electron microscopy analysis of the influence of mycorrhization on the subcellular localisation of Na+ and Cl- in roots showed that the hyphal mantle did not diminish salt accumulation in root cell walls, indicating that mycorrhization did not provide a physical barrier against excess salinity. In the absence of salt stress, mycorrhizal poplar roots contained higher Na+ and Cl- concentrations than non-mycorrhizal poplar roots. Paxillus involutus hyphae produced H2O2 in the mantle but not in the Hartig net or in pure culture. Salt exposure resulted in H2O2 formation in cortical cells of both non-mycorrhizal and mycorrhizal poplar and stimulated peroxidase but not superoxide dismutase activities. This shows that mature ectomycorrhiza was unable to suppress salt-induced oxidative stress. Element analyses suggest that improved performance of mycorrhizal poplar under salt stress may result from diminished xylem loading of Na+ and increased supply with K+. peerReviewed |
Databáze: | OpenAIRE |
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