Effects of cadmium on non‐mycorrhizal and mycorrhizal Norway spruce seedlings [<i>Picea abies</i> (L.) Karst.] and its ectomycorrhizal fungus <i>Laccaria laccata</i> (Scop, ex Fr.) Bk. &amp; Br.: Sulphate reduction, thiols and distribution of the heavy metal

Galli, Ulrich; Meier, Martin; Brunold, Christian

doi:10.1111/j.1469-8137.1993.tb03932.x

Cited by 60 publications

(24 citation statements)

References 38 publications

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“…This class of metallothioneins is now known to be widespread in fungi (Kneer et al, 1992). In a study of the effects of cadmium on Norway spruce seedlings infected with Laccaria laccata, phytochelatins were detected in mycorrhizal roots, but neither these, nor other metallothioneins, were present in the isolated fungus (Galli, Meier & Brunold, 1993).…”

Section: Introductionmentioning

confidence: 99%

Copper‐binding proteins in ectomycorrhizal fungi

1997

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added copper was examined in isolates of Laccaria laccata (Scop, ex Fr,) Cooke and Poxilhis involutus (Batsch ex Fr,) Fr, taken from copper-contaminated and uncontaminated sites, and in a single isolate oi Scleroderma citrinum Pers, from a contaminated site. Two isolates of Laccaria (GLac4 and ELacl) grew better in 1-5 mM and 2-5 mM copper than a third (Lac3G) and were considered to be more tolerant. Amongst five isolates of P, involutus, three (WJPax2R, GPaxRSp2 and Pax4) were capable of growth in media containing 4-0 mM copper and were regarded as tolerant. All isolates of both Laccaria and Paxillus were capable of some growth in 2-5 mM copper, but S. citriinim was much more copper-sensitive and the concentration had to be reduced at least 10-fold before any growth occurred. Tolerance of isolates was not related to whether they were taken from copper-contaminated or uncontaminated sites. Copper-binding proteins were detected in response to copper in the culture media in the two tolerant isolates of Laccaria (GLac4 and ELacl) but not in the least tolerant isolate. In Paxilhis, similar proteins were found in two tolerant isolates (GPaxRSp2 and Pax4) but not in WJPax2R, which was also regarded as tolerant, nor in any of the less tolerant isolates. Copper-binding proteins were not detected in S. citrinum. The copper-binding protein purified from the Laccaria isolate ELacl appeared as a single band in modified SDS-PAGE electrophoresis. Its molecular mass and spectral characteristics were consistent with it being a metallothionein.

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Section: Introductionmentioning

confidence: 99%

Copper‐binding proteins in ectomycorrhizal fungi

1997

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“…Thiol compounds, including reduced glutathione (␥-glutamyl cysteinyl glycine), phytochelatins (PCs), and metallothioneins, are essential components of Cd detoxification pathways in various organisms (5)(6)(7)11). Thiol composition of ectomycorrhizal fungi has not been studied in detail, although P. involutus and Laccaria laccata accumulate glutathione when exposed to Cd (7,22).…”

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confidence: 99%

“…Thiol composition of ectomycorrhizal fungi has not been studied in detail, although P. involutus and Laccaria laccata accumulate glutathione when exposed to Cd (7,22). Reduced glutathione is the most abundant nonprotein thiol component of eukaryotic cells, acts as a free radical scavenger, and reacts with various oxidants to produce oxidized glutathione (17).…”

mentioning

confidence: 99%

Cadmium-Responsive Thiols in the Ectomycorrhizal Fungus Paxillus involutus

Courbot

Diez²,

Ruotolo

et al. 2004

Appl Environ Microbiol

120

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Molecular and cellular mechanisms underlying the sustained metal tolerance of ectomycorrhizal fungi are largely unknown. Some of the main mechanisms involved in metal detoxification appear to involve the chelation of metal ions in the cytosol with thiol-containing compounds, such as glutathione, phytochelatins, or metallothioneins. We used an improved high-performance liquid chromatography method for the simultaneous measurement of thiol-containing compounds from cysteine and its derivatives (␥-glutamylcysteine, glutathione) to higher-molecular-mass compounds (phytochelatins). We found that glutathione and ␥-glutamylcysteine contents increased when the ectomycorrhizal fungus Paxillus involutus was exposed to cadmium. An additional compound with a 3-kDa molecular mass, most probably related to a metallothionein, increased drastically in mycelia exposed to cadmium. The relative lack of phytochelatins and the presence of a putative metallothionein suggest that ectomycorrhizal fungi may use a different means to tolerate heavy metals, such as Cd, than do their plant hosts.The response of ectomycorrhizal fungi to toxic metals is important, since these organisms are present at polluted sites, participate in crucial symbiotic relationships with trees that grow at these sites, and alleviate metal toxicity in the host plants (8,13,26). Paxillus involutus is an ectomycorrhizal fungus with a high tolerance to cadmium, one of the most toxic heavy metals, that can form symbioses with a broad range of host species. The uptake of metals by ectomycorrhizal fungi (2) and the effects of metals on biomass production (3) and nutrient uptake (1) in ectomycorrhizal fungi have been studied. The expression of enzymes involved in antioxidative response mechanisms is regulated by Cd in ectomycorrhizal fungi (12,22) and in mycorrhizal roots of Pinus sylvestris associated with P. involutus (26).Thiol compounds, including reduced glutathione (␥-glutamyl cysteinyl glycine), phytochelatins (PCs), and metallothioneins, are essential components of Cd detoxification pathways in various organisms (5-7, 11). Thiol composition of ectomycorrhizal fungi has not been studied in detail, although P. involutus and Laccaria laccata accumulate glutathione when exposed to Cd (7,22). Reduced glutathione is the most abundant nonprotein thiol component of eukaryotic cells, acts as a free radical scavenger, and reacts with various oxidants to produce oxidized glutathione (17). Phytochelatins are a family of small cysteinerich peptides capable of binding heavy metal ions via their SH group. The general structure of this set of peptides is [␥-GluCys] n -gly (n ϭ 2 to 11). Phytochelatins are enzymatically synthesized from glutathione and have been found in some fungi, algae, and all plant species examined so far (for reviews, see references 4, 5, and 23). Phytochelatin synthase (␥-glutamylcysteine dipeptidyl transpeptidase; EC 2.3.2.15) catalyzes the addition of the ␥-glutamylcysteine (␥-GluCys) moiety of glutathione onto another glutathione molecule (to produce PC...

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“…Decreased uptake in plants exposed to toxic concentrations of metals may provide some protection against metal toxicity, but the degree of protection differs among fungal isolates, metal elements and experimental conditions (Galli et al 1994). At high levels of Cd exposure, arbuscular mycorrhizal (AM) fungal colonization reduced Cd uptake, whereas at lower levels of exposure or low Cd availability, AM either enhanced or reduced Cd uptake (Schüepp et al 1987;El-Kerbawy et al 1989;Galli et al 1993). A recent study with bean and maize plants showed a significant increase in Cd uptake by plants infected with an AM fungus, Glomus mosseae .…”

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confidence: 99%

Cadmium accumulation in crops

Grant¹,

Buckley²,

Bailey³

et al. 1998

Can. J. Plant Sci.

331

180

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Cadmium is a heavy metal present in soils from natural and anthropogenic sources. Plant uptake of Cd at levels present in the soil solution is dependent on a system that is largely metabolically mediated and competitive with the uptake system for Zn and possibly other metals. Much of the Cd taken up by plants is retained in the root, but a portion is translocated to the aerial portions of the plant and into the seed. The amount of Cd accumulated and translocated in plants varies with species and with cultivars within species. Soil, environmental and management factors impact on the amount of Cd accumulated in plants. Potential methods of reducing the accumulation of Cd in crops include reduction of Cd input to the soil system, site selection, management practices which decrease the concentration of Cd in the soil solution and its uptake and translocation by plants, and development and production of plant cultivars with the genetic tendency for low Cd uptake.

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Effects of cadmium on non‐mycorrhizal and mycorrhizal Norway spruce seedlings [Picea abies (L.) Karst.] and its ectomycorrhizal fungus Laccaria laccata (Scop, ex Fr.) Bk. & Br.: Sulphate reduction, thiols and distribution of the heavy metal

Cited by 60 publications

References 38 publications

Copper‐binding proteins in ectomycorrhizal fungi

Copper‐binding proteins in ectomycorrhizal fungi

Cadmium-Responsive Thiols in the Ectomycorrhizal Fungus Paxillus involutus

Cadmium accumulation in crops

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