METALS IN SUILLUS · Subcellular localisation of metals in the ectomycorrhizal fungus Suillus bovinus and its host plant Pinus sylvestris: a comparative study of metal tolerant and non-tolerant isolates
6РП — Действия „Мария Кюри“
- Период
- 2006-10-01 → 2008-09-30
- Финансиране от ЕС
- 158 218 €
- Участници
- 1
- Схема
- EIF
Линиите свързват координатора с партньорите.
Накратко на български
Разпределението на цинк в гъбата Suillus bovinus и борта на корените на европейски черен бор показва как тези организми реагират на тежки метали. Това помага да се разберат механизмите, чрез които гъбите предпазват себе си и растенията от токсичност.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - METALS IN SUILLUS (Subcellular localisation of metals in the ectomycorrhizal fungus Suillus bovinus and its host plant Pinus sylvestris: a comparative study ...)
Isolates of Suillus sp. thriving on metal-contaminated sites show increased levels of tolerance to the metals that are enriched in the soil. The mechanisms by which these ectomycorrhizal (ECM) fungi provide protection against metal toxicity, to themselves and host plants are still unresolved. Understanding heavy-metal tolerance very often first requires knowledge of the spatial distribution of Zn within the fungus and plant and its chemical forms. To characterise the species and spatial distribution of Zn within the fungus and plant, synchrotron based techniques were used; including micro X-ray fluorescence (miuXRF) and Zn K-edge extended X-ray absorption fine structure spectroscopy, performed in bulk and to micrometer-scale resolution (EXAFS and miuEXAFS). In the fungi three Zn pools were identified including Zn bound to organic acids in solution, Zn bound to polysaccharides of the cell wall and Zn-organic acid complexes in solid state. The presence of organic acids was confirmed by capillary zone electrophoresis. We only recorded slight differences of Zn speciation between Zn tolerant and Zn sensitive isolates. Imaging of Zn localisation using fluorescent probes showed no differential compartmentation between vacuole and cell wall between both isolates. So Zn tolerance seems to rely mostly on a limited Zn uptake or enhanced Zn efflux. In the plant-fungal symbiosis Zn was located predominantly into the fungal mantle around the root and in the external mycelium. On the contrary, in non mycorrhizal roots Zn was located mainly into the vascular cylinder. This study characterised for the first time the different compartments of Zn accumulation within the plant-fungal associations and the speciation of Zn in each compartment. It provided new insights on the mechanisms of Zn tolerance and Zn partitioning between fungal and root cells. Such type of information is important for the design of phytoremediation techniques, in this case for the revegetation of metal-contaminated areas. Our study also shows the great interest of synchrotron tools in environmental biology, and might attract new users to such facilities.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
Zinc and copper are essential nutrients required for many biological processes (e.g. cofactor in many proteins). Despite their importance, excess Zn and Cu are toxic. For this reason, organisms have evolved with mechanisms of metal homeostasis that tightly control the intracellular level of metals when extra-cellular concentrations change. Genetic adaptation towards higher Zn and Cu tolerance was found in ectomycorrhizal fungi of the genus Suillus, originating from highly metal contaminated areas. A better understanding of the sub-cellular compartmentalization of these metals in the fungal cells would give insight into the tolerance mechanism, since the intracellular localisation of the metals and the chemical form wherein they appear will determine the toxicity of the metal for the ectomycorrhizal fungus and eventually for its host plant. First, Zn and Cu will be localised with the commonly used techniques; electron microscopy in combination with energy dispersive X-ray microanalysis.To characterize the species and spatial distribution of Zn-Cu within the fungus and plant, synchrotron based techniques will be used; including X-ray fluorescence and K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy, all performed to micrometer-scale resolution. Since we have no experience with the latter techniques we will collaborate with Dr Sarret (LGIT, Universite J.Fourier, Grenoble). She has a lot of experience in the structural determination of metals by EXAFS spectroscopy in plants and fungi. Bulk EXAFS measurements will take place at the European Synchrotron Radiation facility in Grenoble, on the French beam line FAME.The subcellular localisation and speciation of Zn-Cu will be investigated at the micron scale by synchrotron-based x-ray microfluorescenc e and uEXAFS spectroscopy. Such technique is available on beam line 10.3.2 at the ALS synchrotron in Berkeley (USA), where the LGIT have access through a 3-year approved program.
Оригинален текст от CORDIS (на английски).
Участници
- UNIVERSITE JOSEPH FOURIER - GRENOBLE 1 · GRENOBLEКоординаторФранция
Връзки
Данни: CORDIS, © Европейски съюз