Nickel resistance mechanisms in yeasts and other fungi

Joho, Masanori; Inouhe, Masahiro; Tohoyama, Hiroshi; Murayama, Tetsuo

doi:10.1007/bf01569899

Cited by 82 publications

(50 citation statements)

References 67 publications

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“…However, in contrast to previous reports , these patterns did not reflect the results on Ni sensitivity, i.e., the nonserpentine and Ni-susceptible isolate 4,28CT5 cannot be distinguished from the Ni-insensitive serpentine isolates on the basis of the Ni accumulation profiles. There are various mechanisms involved in metal tolerance in ECM fungi (Bellion et al 2006) and that have been described in Niresistant mutants of yeasts and filamentous fungi (Joho et al 1995). In this work, two profiles of Ni accumulation emerged among our Ni-insensitive serpentine isolates, suggesting that different mechanisms may be operating.…”

Section: Discussionmentioning

confidence: 56%

Genetic diversity and differential in vitro responses to Ni in Cenococcum geophilum isolates from serpentine soils in Portugal

et al. 2007

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Amplified fragment length polymorphism (AFLP) analysis was used to investigate the genetic diversity in isolates of the ectomycorrhizal fungus Cenococcum geophilum from serpentine and non-serpentine soils in Portugal. A high degree of genetic diversity was found among C. geophilum isolates; AFLP fingerprints showed that all the isolates were genetically distinct. We also assessed the in vitro Ni sensitivity in three serpentine isolates and one non-serpentine isolate. Only the nonserpentine isolate was significantly affected by the addition of Ni to the growth medium. At 30 μg g −1 Ni, radial growth rate and biomass accumulation decreased to 73.3 and 71.6% of control, respectively, a highly significant inhibitory effect. Nickel at this concentration had no significant inhibitory effect on serpentine isolates, and so the fitness of serpentine isolates, as evaluated by radial growth rate and biomass yield, is likely unaffected by Ni in the field. In all isolates, the Ni concentration in the mycelia increased with increasing Ni concentration in the growth medium, but two profiles of Ni accumulation were identified. One serpentine isolate showed a linear trend of Ni accumulation. At the highest Ni exposure, the concentration of Ni in the mycelium of this isolate was in the hyperaccumulation range for Ni as defined for higher plants. In the remaining isolates, Ni accumulation was less pronounced and seems to approach a plateau at 30 μg g −1 Ni. Because two profiles of Ni accumulation emerged among our Ni-insensitive serpentine isolates, this result suggests that different Ni detoxification pathways may be operating. The nonserpentine isolate whose growth was significantly affected by Ni was separated from the other isolates in the genetic analysis, suggesting a genetic basis for the Ni-sensitivity trait. This hypothesis is further supported by the fact that all isolates were maintained on medium without added Ni to avoid carry-over effects. However, because AFLP analysis failed to distinguish between serpentine and non-serpentine isolates, we cannot conclude that Ni insensitivity among our serpentine isolates is due to evolutionary adaptation. Screening a larger number of isolates, from different geographical origins and environments, should clarify the relationships between genetic diversity, morphology, and physiology in this important species.

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Section: Discussionmentioning

confidence: 56%

Genetic diversity and differential in vitro responses to Ni in Cenococcum geophilum isolates from serpentine soils in Portugal

et al. 2007

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“…Judging from the progressive organelle response, Ni 2+ was most likely taken up by the hyphal tip cells which are adapted for rapid nutrient uptake ( Jennings & Lysek, 1996). Nickel uptake is thoroughly documented in other fungal cells (Mohan et al, 1984;Joho et al, 1995;Nishimura et al, 1998;Dönmez & Aksu, 2001) and it has been localized within Hebeloma crustuliniforme ectomycorrhizas (Brunner & Frey, 2000). Vacuole vesiculation observed during Ni 2+ exposure also occurs by exposure to acids, cytoskeletal drugs, fixatives and fluorescent probes (Wilson et al, 1990;Cole et al, 1997Cole et al, , 2000Bachewich & Heath, 1999;Hyde et al, 1999), suggesting that this is a general response to toxins.…”

Section: +mentioning

confidence: 99%

Ni2+ induces changes in the morphology of vacuoles, mitochondria and microtubules in Paxillus involutus cells

Tuszyńska

2006

New Phytol

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Summary• Organelles of ectomycorrhizal fungi are known to respond to changes in the extracellular environment. The response of vacuoles, mitochondria and microtubules to short-term nickel (Ni 2+ ) exposure were investigated in hyphal tip cells of a Paxillus involutus from a heavy metal-rich soil.• Vacuoles, mitochondria and microtubules were labelled with Oregon Green ® 488 carboxylic acid diacetate, 3,3 ′ -dihexyloxacarbocyanine iodide (DiOC 6 (3)) and anti-α -tubulin antibodies, respectively; hyphae were treated with NiSO 4 in the range of 0-1 mmol l − 1 and examined microscopically.• Untreated hyphal tip cells contained tubular vacuole and mitochondrial networks. Ni 2+ caused loss of organelle tubularity and severe microtubule disruption that were exposure-time and concentration dependent. Fine tubular vacuoles thickened and eventually became spherical in some hyphae, tubular mitochondria fragmented and microtubules shortened and aggregated into patches in most hyphae. Tubular vacuoles reformed on NiSO 4 removal and tubular mitochondria in the presence of NiSO 4 suggesting cellular detoxification.• These results demonstrate that Ni 2+ induces changes in organelle and microtubule morphology. Recovery of tubular organelles to pretreatment morphology after Ni 2+ exposure suggests cellular detoxification of the metal ion.

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“…In Saccharomyces cerevisiae, Cu has been located both in the cytoplasm as well as the cell wall 27 . Sequestration of Ni into vacuole associated with free histidine has been reported in yeasts and other fungi 14 .…”

Section: Characterization Of Ni R Mutantsmentioning

confidence: 87%

“…Most fungi accumulate metals by employing physico-chemical mechanisms and transport systems of varying specifi city [14][15][16] . However, both essential and non-essential metals in concentrations, higher than the optimal level, prove toxic to organisms.…”

Section: Development Of Ni Resistant Mutantsmentioning

confidence: 99%

Development and characterization of nickel accumulating mutants of Aspergillus nidulans

Tripathi

Srivastava

2007

Indian J Microbiol

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Stable mutants of Aspergillus nidulans, resistant to 1 mM Ni were developed by step-by-step repeated culturing of the fungus on the medium containing increasing concentrations of nickel chloride. Characterization of mutants could differentiate them into two categories Ni R I and Ni R II. Each category of mutants exhibited alterations in growth, conidial germination and melanin secretion both in Ni-free and Ni-containing media. Ni R II mutants were little slow in growth with sparse mycelia and conidiation but showed high melanin secretion and higher Ni-uptake in comparison to Ni R I mutant. Studies involving metabolic and translational inhibitors could prove that Niaccumulation was biphasic. The initial energy independent surface accumulation was found to be followed by energy dependent intarcellular uptake. Increase in the concentration of the metal in the medium or the time of exposure did not proportionately increase the metal uptake by the mutants. Ni -uptake followed Michaelis-Menton saturation kinetics, which was enhanced under optimum pH of 6.5-7.5 and reduced complexity of the medium due to free availability of ions. Resistance to Ni was found to be constitutive in Ni R I mutant, and could be induced in Ni R II mutant.

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Nickel resistance mechanisms in yeasts and other fungi

Cited by 82 publications

References 67 publications

Genetic diversity and differential in vitro responses to Ni in Cenococcum geophilum isolates from serpentine soils in Portugal

Genetic diversity and differential in vitro responses to Ni in Cenococcum geophilum isolates from serpentine soils in Portugal

Ni2+ induces changes in the morphology of vacuoles, mitochondria and microtubules in Paxillus involutus cells

Development and characterization of nickel accumulating mutants of Aspergillus nidulans

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