Impact of Heavy Metals on Water Loss from Lichen Thalli

Chettri, Mukesh Kumar; Sawidis, Thomas

doi:10.1006/eesa.1997.1532

Cited by 17 publications

(4 citation statements)

References 53 publications

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“…SA elevation and ABA reduction may be attributed to heavy metal stress inhibition by E. ludwigii SAK5 and E. indicum SA22. ABA may be upregulated by water loss during heavy metal stress [102]; ABA has been reported to reduce water loss through stomatal closure by activating stress-related genes [103,104]. Similar results were reported for white bean plants under Cd stress, which showed ABA enhancement and stomatal resistance [105].…”

Section: Discussionmentioning

confidence: 60%

Metal Resistant Endophytic Bacteria Reduces Cadmium, Nickel Toxicity, and Enhances Expression of Metal Stress Related Genes with Improved Growth of Oryza Sativa, via Regulating Its Antioxidant Machinery and Endogenous Hormones

Jan

Khan

Asaf

et al. 2019

Plants

130

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The tolerance of plant growth-promoting endophytes (PGPEs) against various concentrations of cadmium (Cd) and nickel (Ni) was investigated. Two glutathione-producing bacterial strains (Enterobacter ludwigii SAK5 and Exiguobacterium indicum SA22) were screened for Cd and Ni accumulation and tolerance in contaminated media, which showed resistance up to 1.0 mM. Both strains were further evaluated by inoculating specific plants with the bacteria for five days prior to heavy metal treatment (0.5 and 1.0 mM). The enhancement of biomass and growth attributes such as the root length, shoot length, root fresh weight, shoot fresh weight, and chlorophyll content were compared between treated inoculated plants and treated non-inoculated plants. Both strains significantly increased the accumulation of Cd and Ni in inoculated plants. The accumulation of both heavy metals was higher in the roots than in the shoots, however; Ni accumulation was greater than Cd. Heavy metal stress-responsive genes such as OsGST, OsMTP1, and OsPCS1 were significantly upregulated in treated non-inoculated plants compared with treated inoculated plants, suggesting that both strains reduced heavy metal stress. Similarly, abscisic acid (ABA) was increased with increased heavy metal concentration; however, it was reduced in inoculated plants compared with non-inoculated plants. Salicylic acid (SA) was found to exert synergistic effects with ABA. The application of suitable endophytic bacteria can protect against heavy metal hyperaccumulation by enhancing detoxification mechanisms.

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Section: Discussionmentioning

confidence: 60%

Metal Resistant Endophytic Bacteria Reduces Cadmium, Nickel Toxicity, and Enhances Expression of Metal Stress Related Genes with Improved Growth of Oryza Sativa, via Regulating Its Antioxidant Machinery and Endogenous Hormones

Jan

Khan

Asaf

et al. 2019

Plants

130

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“…Soluble metals, if located extracellularly, are assumed to be less important in causing immediate metabolic effects than metals located intracellularly (Brown & Brown, 1991). As reported by various authors (Nieboer et al ., 1978; Branquinho et al ., 1997b; Chettri & Sawidis, 1997; Branquinho, 2001), heavy metals are mostly accumulated on the surface layers of lichen cell walls because of the negatively charged anionic sites present in these structures, and only traces of supplied metals are normally observed intracellularly. The presence in lichens of a surrounding layer of recently discovered water‐repellent proteins, the hydrophobins (Wessels, 2000; Dyer, 2002; Scherrer et al ., 2002) (produced only by the mycobiont) may well play a role in further protecting the thalli against the indiscriminate intracellular penetration of heavy metal‐containing solutions.…”

Section: Discussionmentioning

confidence: 99%

“…Lichens can grow on substrates rich in heavy metals (Beck, 1999), and their ability to accumulate metals, mainly in the apoplastic space of their multilayered structures, is well documented (Tyler, 1989; Sawidis et al ., 1995; Chettri et al ., 1997, 1998; Kauppi et al ., 1998). Although heavy metals such as cadmium (Cd), lead (Pb) and zinc (Zn) may enter the symplastic space of thalli only in trace amounts, they can greatly affect lichen metabolism by causing a reduction in photosynthetic rate, chlorophyll degradation and water loss (Branquinho et al ., 1997a,b; Chettri & Sawidis, 1997; Chettri et al ., 1998; Branquinho et al ., 1999). However, both accumulation and toxic effects of metals in lichens can vary as a consequence of metal exposure, environmental factors and lichen species (Branquinho et al ., 1997b; Chettri et al ., 1997).…”

Section: Introductionmentioning

confidence: 99%

Lichens respond to heavy metals by phytochelatin synthesis

et al. 2002

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Summary• The main aims of this paper are to investigate: if widespread lichen species ( Xanthoria parietina , Physconia grisea and Physcia adscendens , collected in Italy and Poland) exposed to cadmium (Cd), lead (Pb) and zinc (Zn) synthesize phytochelatins; whether phytochelatins are synthesized by the heterotrophic fungus (mycobiont) or by the photosynthetic alga (photobiont), or by both of the partners; and if there are significant differences in phytochelatin production in the same lichen species growing at different latitudes.• In the lichens investigated, Cd, Pb and Zn induced the biosynthesis of phytochelatins (PC 2 , PC 3 and PC 4 ) and some DES-GLYCIL derivatives. However, only the photobiont partners (the green microalgae of the genus Trebouxia ) were capable of phytochelatin production and, by contrast, aposymbiotically grown mycobionts only produced glutathione.• The Cd-exposed lichens grown in Italy produced significantly larger amounts of phytochelatins than the same species grown in Poland. An opposite trend was observed in Pb-exposed lichens.• The trebouxioid lichens may gain an ecological advantage from their capability to counter heavy metal stress with prompt phytochelatin synthesis.

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“…Many authors in their researches show the influence of hydrogen ions (pH) on metals sorption. [3,4] Locally, the kind and amount of the pollutions imission depends on climate conditions, wind force and direction, intensity and kind of rainfall, temperature and atmospheric pressure. [3,5] The results of the bark of model trees analysis taken on surfaces on different distance from source emission can illustrate the problem of spreading of pollutions.…”

Section: Introductionmentioning

confidence: 99%

Scots pine bark, topsoil and pedofauna as indicators of transport pollutions in terrestrial ecosystems

Marko-Worłowska

Chrzan

Łaciak

2011

Journal of Environmental Science and Health, Part A

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The impact of the motorway on pollution was evaluated by determining chosen heavy metals and acid reaction (pH) in the pine bark, in forest and meadow topsoil. The content of these environmental contaminants was determined in the topsoil and in the bark of around 40 year-old Scots pines (Pinus sylvestris L.) growing right next to the soil analyzed. The pollutants were examined at localities situated around 5, 200, 1500 m away from the motorway. To evaluate influence of Cd, Pb, Zn, Cu and the topsoil pH on pedofauna, five meadows localities situated 1, 20, 40, 150, 1550 m away from the motorway were examined. It was detected that in the forest habitats analyzed the bark was characterized by considerably higher acidity (pH 3.14-3.88) than the topsoil of the pines analyzed (pH 5.45-7.22). Except of Cd at locality 200 m and Cu at 1500 m from motorway, the higher concentration of heavy metals was noted in topsoil. In the meadow soil of the locality 150 m from the motorway the highest concentrations of Cd and Zn were detected. The greatest diversity of the meso and macrofauna and trophic relations the most resembling natural were detected in the area furthest away from the motorway, where the content of the heavy metals was the lowest. The lowest density and diversity of meso- and macrofauna were detected in the area situated 40 m, where the concentration of heavy metals was higher than at 1, 20 and 1550 m from the motorway situated localities.

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Impact of Heavy Metals on Water Loss from Lichen Thalli

Cited by 17 publications

References 53 publications

Metal Resistant Endophytic Bacteria Reduces Cadmium, Nickel Toxicity, and Enhances Expression of Metal Stress Related Genes with Improved Growth of Oryza Sativa, via Regulating Its Antioxidant Machinery and Endogenous Hormones

Metal Resistant Endophytic Bacteria Reduces Cadmium, Nickel Toxicity, and Enhances Expression of Metal Stress Related Genes with Improved Growth of Oryza Sativa, via Regulating Its Antioxidant Machinery and Endogenous Hormones

Lichens respond to heavy metals by phytochelatin synthesis

Scots pine bark, topsoil and pedofauna as indicators of transport pollutions in terrestrial ecosystems

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