Heavy metal tolerance of Minuartia verna

Neumann, D.; Nieden, Uta zur; Schwieger, Wilhelm; Leopold, Ines; Lichtenberger, O.

doi:10.1016/s0176-1617(97)80044-2

Cited by 103 publications

(42 citation statements)

References 23 publications

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“…By using a fractionation technique, it has been shown that the cell wall bound fraction of Zn in roots, stems, sheaths and leaves of rice seedlings increased after Si addition (Gu et al 2012). Likewise, in Minuartia verna, a Si-accumulator dicotyledonous, Zn silicates were detected in the leaf epidermal cell wall, which explains its Zn tolerance (Neumann et al 1997). The similar location of Si and Zn could be explained by the similar xylem transport mechanism, related with the transpiration rate.…”

Section: Zinc Deficiencymentioning

confidence: 92%

Can silicon partially alleviate micronutrient deficiency in plants? a review

Hernández‐Apaolaza

2014

Planta

136

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Silicon protects plants against various biotic and abiotic stresses, including metal toxicity. Under a high metal concentration, Si can externally decrease metal availability to the plant by its precipitation in the growth media, and Si also affects the metal distribution inside the plant, diminishing the damage. Could Si also protect plants against metal deficiency stress? Recently, the physiological role of Si in relation to micronutrients deficiency symptoms has been assessed in several plant species in hydroponics. In cucumber, Si supply mitigated the symptoms of Fe deficiency, but this effect was not clear under Zn-or Mndeficiency conditions. The main factor controlling this beneficial effect seems to be the Si contribution to the formation of metal deposits in the root and/or leaves apoplast and its role in their following remobilization when required. The enhancement of the content of long-distance transport molecules (such as citrate) due to Si addition should also contribute to the metal transport from root to shoot, which will diminish deficiency symptoms.

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Section: Zinc Deficiencymentioning

confidence: 92%

Can silicon partially alleviate micronutrient deficiency in plants? a review

Hernández‐Apaolaza

2014

Planta

136

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“…Thus, root tip cells that are predominantly devoid of large central vacuoles would therefore have to rely on Mn extrusion into the apoplast. Similarly, hydathodes are typically found at the end of vascular tissues and participate in the secretion of water that contains excess salts, including transition metals (38). In contrast, vacuolar deposition of heavy metals is predominant in leaf and root epidermal tissue where MTP11 expression is relatively low.…”

Section: Mtp11 Expression Patternsmentioning

confidence: 99%

A secretory pathway-localized cation diffusion facilitator confers plant manganese tolerance

Peiter

Montanini

Gobert

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

246

262

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Manganese toxicity is a major problem for plant growth in acidic soils, but cellular mechanisms that facilitate growth in such conditions have not been clearly delineated. Established mechanisms that counter metal toxicity in plants involve chelation and cytoplasmic export of the metal across the plasma or vacuolar membranes out of the cell or sequestered into a large organelle, respectively. We report here that expression of the Arabidopsis and poplar MTP11 cation diffusion facilitators in a manganesehypersensitive yeast mutant restores manganese tolerance to wild-type levels. Microsomes from yeast expressing AtMTP11 exhibit enhanced manganese uptake. In accord with a presumed function of MTP11 in manganese tolerance, Arabidopsis mtp11 mutants are hypersensitive to elevated levels of manganese, whereas plants overexpressing MTP11 are hypertolerant. In contrast, sensitivity to manganese deficiency is slightly decreased in mutants and increased in overexpressing lines. Promoter-GUS studies showed that AtMTP11 is most highly expressed in root tips, shoot margins, and hydathodes, but not in epidermal cells and trichomes, which are generally associated with manganese accumulation. Surprisingly, imaging of MTP11-EYFP fusions demonstrated that MTP11 localizes neither to the plasma membrane nor to the vacuole, but to a punctate endomembrane compartment that largely coincides with the distribution of the trans-Golgi marker sialyl transferase. Golgi-based manganese accumulation might therefore result in manganese tolerance through vesicular trafficking and exocytosis. In accord with this proposal, Arabidopsis mtp11 mutants exhibit enhanced manganese concentrations in shoots and roots. We propose that Golgi-mediated exocytosis comprises a conserved mechanism for heavy metal tolerance in plants.Golgi ͉ heavy metal transport ͉ metal tolerance protein ͉ metal trafficking ͉ manganese transporter T ransition metals are required by living systems where they perform a wide variety of functions as cofactors for enzymes and transcription factors. Transition metals are also present in many environments at potentially toxic concentrations, and this has led to the evolution of mechanisms that counter toxicity. In plants exposed to high concentrations of transition metals in the soil, binding of the metals to phytochelatins in the cytosol lowers metal activity (1). Additionally, metals can be removed from the cytosol through the action of metal transporters. Transporters involved in metal tolerance localize to the plasma membrane, thereby removing metals from the cell, or to the vacuolar membrane, where the metal can be sequestered into a large and metabolically relatively inert intracellular compartment (2).Manganese is the second most prevalent transition metal, after iron, in the Earth's crust and an essential micronutrient for all organisms, including humans and plants (3). In addition to being a cofactor for a variety of enzymes (including various decarboxylases of the tricarboxylic acid cycle, RNA polymerases, and numerous glyco...

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“…Minuartia verna sp. hercynica growing on heavy metal contaminated medieval mine dumps has been found to have high concentrations of Fe, Cu, Zn and Pb associated with Si contained in the cell walls (Neumann et al 1997). An alternative strategy for controlling intracellular metal levels at the plasma membrane involves the active efflux of metal ions although there is very little direct evidence for such a process in plant system.…”

Section: Tolerance and Detoxification Of Metal Ionsmentioning

confidence: 99%

Biochemical changes and adaptive strategies of plants under heavy metal stress

2011

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Heavy metal contamination of soil, aqueous waste stream and ground water causes major environmental and human health problems. Heavy metals are major environmental pollutants when they are present in high concentration in soil and show potential toxic effects on growth and development in plants. Due to unabated, indiscriminate and uncontrolled discharge of hazardous chemicals including heavy metals into the environment, plant continuously have to face various environmental constraints. In plants, seed germination is the first exchange interface with the surrounding medium and has been considered as highly sensitive to environmental changes. One of the crucial events during seed germination entails mobilization of seed reserves which is indispensable for the growth of embryonic axis. But, metabolic alterations by heavy metal exposure are known to depress the mobilization and utilization of reserve food by affecting the activity of hydrolytic enzymes. Some plants possess a range of potential mechanisms that may be involved in the detoxification of heavy metals by which they manage to survive under metal stress. High tolerance to heavy metal toxicity could rely either on reduced uptake or increase planned internal sequestration which is manifested by an interaction between a genotype and its environment. Such mechanism involves the binding of heavy metals to cell wall, immobilization, exclusion of the plasma membrane, efflux of these toxic metal ions, reduction of heavy metal transport, compartmentalization and metal chelation by tonoplast located transporters and expression of more general stress response mechanisms such as stress proteins. It is important to understand the toxicity response of plant to heavy metals so that we can utilize appropriate plant species in the rehabilitation of contaminated areas. Therefore, in the present review attempts have been made to evaluate the effects of increasing level of heavy metal in soils on the key behavior of hydrolytic and nitrogen assimilation enzymes. Additionally, it also provides a broad overview of the strategies adopted by plants against heavy metal stress.

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Heavy metal tolerance of Minuartia verna

Cited by 103 publications

References 23 publications

Can silicon partially alleviate micronutrient deficiency in plants? a review

Can silicon partially alleviate micronutrient deficiency in plants? a review

A secretory pathway-localized cation diffusion facilitator confers plant manganese tolerance

Biochemical changes and adaptive strategies of plants under heavy metal stress

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