Some relevant Published databases
We have listed several relevant databases with short introductions and links with their active or dead mood to make it more convenient and easier for researchers, our aim in giving the database's dead mood is to ensure that researchers may still get knowledge from the articles.
A summary of plant proteome analyses involved in metal toxicity: Pollution of soils by heavy metals is an ever-growing problem throughout the world, and is the result of human activities as well as geochemical weathering of rocks and other environmental causes such as volcanic eruptions, acid rain and continental dusts. Plants everywhere are continuously exposed to metal-contaminated soils. The uptake of heavy metals not only constrains crop yields, but can also be a major hazard to the health of humans and to the entire ecosystem. Although analysis of gene expression at the mRNA level has enhanced our understanding of the response of plants to heavy metals, many questions regarding the functional translated portions of plant genomes under metal stress remain unanswered. Proteomics offers a new platform for studying complex biological functions involving large numbers and networks of proteins, and can serve as a key tool for revealing the molecular mechanisms that are involved in interactions between toxic metals and plant species. This review focuses on recent developments in the applications of proteomics to the analysis of the responses of plants to heavy metals; such studies provide a deeper understanding of protein responses and the interactions among the possible pathways that are involved in detoxification of toxic metals in plant cells. In addition, the challenges faced by proteomics in understanding the responses of plants to toxic metal are discussed, and some possible future strategies for meeting these challenges are proposed.
Status: Active
Heavy metal contents in wild-growing (native) plant species (milligram per kilogram) : The copper production in Bor (East Serbia) during the last 100 years presents an important source of the pollution of environment. Dust, waste waters, tailing, and air pollutants influence the quality of soil, water, and air. Over 2,000 ha of fertile soil have been damaged by the flotation tailing from Bor’s facilities. The goal of the present work has been to determine the content of Pb, Cu, and Fe in wild plants (17 species) naturally growing in the damaged soil and in fodder crops (nine species) planted at the same place. The content of Pb, Cu, and Fe has been analyzed in damaged soil as well. This study has also searched for native (wild) and cultivated plants which are able to grow in contaminated soil in the area of the intense industrial activity of copper production in Bor, which means that they can accumulate and tolerate heavy metals in their above-ground tissues. It has been found out that the content of all metals in contaminated soil decreases considerably at the end of the experiment. As it has been expected, all plant species could accumulate investigated metals. All tested plants, both wild-growing and cultivated plants, seem to be quite healthy on the substrate which contained extremely high concentrations of copper.
Status: Active
Heavy metal concentrations in leaves of trees in urban areas : Limited data have been published on the chemistry of urban soils and vegetation in the Philippines. The aim of this study is to quantify the concentrations of heavy metals (i.e., Cr, Ni, Cu, Zn, and Pb) in soils and vegetation in the urban landscape of Quezon City, Philippines, and to elucidate the relationships between soil properties and the concentration of heavy metals pertaining to different land uses [i.e., protected forest (LM), park and wildlife area (PA), landfill (PL), urban poor residential and industrial areas (RA), and commercial areas (CA)]. Soil (0–15 cm) and senescent plant leaves were collected and were analyzed for soil properties and heavy metal concentrations. Results revealed that the concentrations of heavy metals (i.e., Cr, Ni, Cu, Zn, and Pb) in urban soils were higher in areas where anthropogenic activities or disturbance (PL, RA, and CA) were dominant as compared to the less disturbed areas (LM and PA). Organic matter and available phosphorous were strongly correlated with heavy metal concentrations, suggesting that heavy metal concentrations were primarily controlled by these soil properties. The average foliar heavy metal concentrations varied, ranging from 0 to 0.4 mg/kg for Cd, 0–10 mg/kg for Cr, 2–22 mg/kg for Cu, 0–5 mg/kg for Pb, and 11–250 mg/kg for Zn. The concentrations of Cd and Cr exceeded the critical threshold concentrations in some plants. Leaves of plants growing in PL (i.e., landfill) showed the highest levels of heavy metal contamination. Our results revealed that anthropogenic activities and disturbance caused by the rapid urbanization of the city are major contributors to the heavy metal accumulation and persistence in the soils in these areas.
Status: Active
Concentrations of the heavy metals present in different plants : Plants are a rich source of elements, and knowledge of their elemental composition determines their use for various purposes, especially for food and medicine. Therefore, it is necessary to create a database of the elemental composition of plants. The present review focuses on the concentration of various heavy metals as reported by various workers from time to time by using different sophisticated techniques. Cluster analysis was applied on the basis of mean values of heavy metals in plants. Co, Cu, and Cr have similar proximities. Cluster analysis was also applied to different families on the basis of their heavy metal contents. Elaeagnaceae, Adoxaceae, Thymelaeaceae, Cupressaceae, and Acoraceae had close proximities with each other. First three components of principal component analysis explained 95.7 % of the total variance. Factor analysis explained four underlying factors for heavy metal analysis. Factor 1 explained for 26.5 % of the total variance and had maximum loadings on Co, Cu, and Cr. Of the total variance, 21.7 % was explained by factor 2 and had maximum loadings on Zn and Cd. Factor 3 accounted for 19.2 % of the total variance and had maximum loadings on Ni and Pb. Mn had maximum loading on factor 4. The mean values of heavy metals as listed in this paper are Cu (18.7 µg/g dw), Mn (99.67 µg/g dw), Cr (22.9 µg/g dw), Co (19.7 µg/g dw), As (1.25 µg/g dw), Hg (0.17 µg/g dw), Zn (94.0 µg/g dw), Pb (6.93 µg/g dw), Cd (26.9 µg/g dw), Ni (19.9 µg/g dw), and Sb (0.25 µg/g dw).
Status: Active
Heavy-metal-induced reactive oxygen species (ROS) production in different plant species : As a result of the industrial revolution, anthropogenic activities have enhanced there distribution of many toxic heavy metals from the earth's crust to different environmental compartments. Environmental pollution by toxic heavy metals is increasing worldwide, and poses a rising threat to both the environment and to human health.Plants are exposed to heavy metals from various sources: mining and refining of ores, fertilizer and pesticide applications, battery chemicals, disposal of solid wastes(including sewage sludge), irrigation with wastewater, vehicular exhaust emissions and adjacent industrial activity.Heavy metals induce various morphological, physiological, and biochemical dysfunctions in plants, either directly or indirectly, and cause various damaging effects. The most frequently documented and earliest consequence of heavy metal toxicity in plants cells is the overproduction of ROS. Unlike redox-active metals such as iron and copper, heavy metals (e.g, Pb, Cd, Ni, AI, Mn and Zn) cannot generate ROS directly by participating in biological redox reactions such as Haber Weiss/Fenton reactions. However, these metals induce ROS generation via different indirect mechanisms, such as stimulating the activity of NADPH oxidases, displacing essential cations from specific binding sites of enzymes and inhibiting enzymatic activities from their affinity for -SH groups on the enzyme.Under normal conditions, ROS play several essential roles in regulating the expression of different genes. Reactive oxygen species control numerous processes like the cell cycle, plant growth, abiotic stress responses, systemic signalling, programmed cell death, pathogen defence and development. Enhanced generation of these species from heavy metal toxicity deteriorates the intrinsic antioxidant defense system of cells, and causes oxidative stress. Cells with oxidative stress display various chemical,biological and physiological toxic symptoms as a result of the interaction between ROS and biomolecules. Heavy-metal-induced ROS cause lipid peroxidation, membrane dismantling and damage to DNA, protein and carbohydrates. Plants have very well-organized defense systems, consisting of enzymatic and non-enzymatic antioxidation processes. The primary defense mechanism for heavy metal detoxification is the reduced absorption of these metals into plants or their sequestration in root cells.Secondary heavy metal tolerance mechanisms include activation of antioxidant enzymes and the binding of heavy metals by phytochelatins, glutathione and amino acids. These defense systems work in combination to manage the cascades of oxidative stress and to defend plant cells from the toxic effects of ROS.In this review, we summarized the biochemiCal processes involved in the over production of ROS as an aftermath to heavy metal exposure. We also described the ROS scavenging process that is associated with the antioxidant defense machinery.Despite considerable progress in understanding the biochemistry of ROS overproduction and scavenging, we still lack in-depth studies on the parameters associated with heavy metal exclusion and tolerance capacity of plants. For example, data about the role of glutathione-glutaredoxin-thioredoxin system in ROS detoxification in plant cells are scarce. Moreover, how ROS mediate glutathionylation (redox signalling)is still not completely understood. Similarly, induction of glutathione and phytochelatins under oxidative stress is very well reported, but it is still unexplained that some studied compounds are not involved in the detoxification mechanisms. Moreover,although the role of metal transporters and gene expression is well established for a few metals and plants, much more research is needed. Eventually, when results for more metals and plants are available, the mechanism of the biochemical and genetic basis of heavy metal detoxification in plants will be better understood. Moreover, by using recently developed genetic and biotechnological tools it may be possible to produce plants that have traits desirable for imparting heavy metal tolerance.
Status: Active
Summary of proteomic studies of plant response to heavy metal stress published between 2003 and 2013 : Plants endure a variety of abiotic and biotic stresses, all of which cause major limitations to production. Among abiotic stressors, heavy metal contamination represents a global environmental problem endangering humans, animals, and plants. Exposure to heavy metals has been documented to induce changes in the expression of plant proteins. Proteins are macromolecules directly responsible for most biological processes in a living cell, while protein function is directly influenced by posttranslational modifications, which cannot be identified through genome studies. Therefore, it is necessary to conduct proteomic studies, which enable the elucidation of the presence and role of proteins under specific environmental conditions. This review attempts to present current knowledge on proteomic techniques developed with an aim to detect the response of plant to heavy metal stress. Significant contributions to a better understanding of the complex mechanisms of plant acclimation to metal stress are also discussed.
Status: Active
Summarised research on Vetiver. : This review briefly elucidates the research undertaken and benefits of using aromatic plants for remediation of heavy metal polluted sites. A sustainable approach to mitigate heavy metal contamination of environment is need of the hour. Phytoremediation has emerged to be one of the most preferable choices for combating the metal pollution problem. Aromatic plants can be used for remediation of contaminated sites as they are non-food crops thus minimizing the risk of food chain contamination. Most promising aromatic plants for phytoremediation of heavy metal contaminated sites have been identified from families – Poaceae, Lamiaceae, Asteraceae, and Geraniaceae. They act as potential phytostabilisers, hyper accumulators, bio-monitors, and facultative metallophytes. Being high value economic crops, monetary benefits can be obtained by growing them in tainted areas instead of food crops. It has been observed that heavy metal stress enhances the essential oil percentage of certain aromatic crops. Research conducted on some major aromatic plants in this context has been highlighted in the present review which suggests that aromatic plants hold a great potential for phytoremediation. It has been reported that essential oil from aromatic crops is not contaminated by heavy metals significantly. Thus, aromatic plants are emerging as an ideal candidate for phytoremediation.
Status: Active
Concentrations of metals (mg/g) present in different medicinal plant parts : http://umbbd.ethz.ch/
Status: Active
Important families, genera and regions of occurrence of hyperaccumulators : In this review, we evaluate the reports published between 1993 and 2011 that address the heavy metal accumulation in 88 medicinal plant species. We compare the safe limits for heavy metals set by governmental agencies vs. the levels at which such metals actually exist in selected medicinal plants. We also evaluate the uses and effectiveness of medicinal plants in health care, and assess the hazards of medicinal plant uses, in view of the growing worldwide use of medicinal plants. From our extensive review of the literature, we discovered that a maximum permissible level (MPL) of Pb is exceeded in 21 plant medicine species, Cd in 44 species, and Hg in 10 species. Vetiveria zizanioides a potential candidate species for the treatment of cardiovascular diseases absorb a wide range of heavy metals from metal-contaminated soils. We believe that this species is the single most impressive example of a potentially hazardous medicinal plant. Based on our review, we endorse the hypothesis that heavy metal accumulation by medicinal plants is mainly caused by extraction of soluble metals from contaminated soil, sediments and air. One continuing problem in protecting consumers of plant-based medicines is that permissible levels of all heavy metals in herbal medicine have not yet been standardized by regulating governmental entities. Moreover, there are few limit tests that exist for heavy metal content of medicinal plants, or permissible limits for essential dietary minerals, in most medicinal plants. The dearth of such limits hamstrings development of medicinal plant research and delays the release of either new or improved versions of medicinal plants or their components. In the present review, we emphasize that medicinal plants are often subjected to heavy metal contamination and that the levels at which these heavy metals sometimes occur exceeds permissible levels for some species. Therefore, collecting medicinal plants from areas that are, or may be, contaminated should be discouraged and banned if possible.
Status: Active
Biodiversity variability and metal accumulation strategies in plants spontaneously inhibiting fly ash lagoon, India : More than 40 years since the discovery of the spectacular New Caledonian hyperaccumulator tree Pycnandra acuminata, knowledge on these unusual plants has advanced considerably. Hundreds of other hyperaccumulators of metal and metalloid elements have since been reported, and new discoveries continue to be made at an accelerated pace. The field has matured and is the current subject of detailed investigations into the molecular biology and physiological aspects of the hyperaccumulation phenomenon, as well as research on ecological interactions. Hyperaccumulator plants have also found useful applications in phyto-extraction technologies, especially in nickel phytomining.
Status: Active
Heavy metal concentrations in the plant tissues : Out of 29 plant species taken into consideration for biodiversity investigations, the present study screened out Cyperus rotundus L., Calotropis procera (Aiton) W.T. Aiton, Croton bonplandianus Baill., Eclipta prostrata (L.) L., and Vernonia cinerea (L.) Less. as the most suitable metal-tolerant plant species (high relative density and frequency) which can grow on metal-laden fly ash (FA) lagoon. Total (aqua-regia), residual (HNO3) and plant available (CaCl2) metal concentrations were assessed for the clean-up of metal-contaminated FA disposal site using naturally colonized plants. The total metal concentration (in mg kg-1) in FA followed an order of Mn (229.8) > Ni (228.4) > Zn (89.4) > Cr (61.2) > Pb (56.6) > Cu (51.5) > Co (41.9) > Cd (9.7). The HNO3- and CaCl2-extracted metals were 0.57–15.68% and 0.03–7.82% of the total metal concentration, respectively. The concentration of Ni and Cr in FA in the present study was highest among the previously studied Indian and average world power plants and Cd, Ni, and Cr were above soil toxicity limit. The variation in total, residual, and plant-available metal (single extraction) concentration indicated the presence of different proportions of metals in FA lagoon which affects the metal uptake potential of the vegetation growing on it. It has been reported that plant-available metal extractant (CaCl2) is the most suitable extractant for assessment of metal transfer from soil to plant. However in the present study, Spearman’s correlation showed best significant correlation between total metal concentration in FA and shoot metal concentration (r = 0.840; p < 0.01) which suggest aqua-regia as the best extractant for understanding the bioavailability and transfer of metal, and in calculation of BCF for moderately contaminated site. It can be stated that plant-available extractant is not always suitable for understanding the availability of metal, but total metal concentration can provide a better insight especially for moderate or low metal-contaminated sites. Principle component analysis revealed that all the plants showed positive correlation with Co and Cd which suggest its subsequent uptake in root and shoot. The biological indices (BCF, BAF, and TF) revealed that E. prostrata (10 mg Cd kg-1) and C. procera (3.5 mg Cd kg-1) can be utilized efficiently for the phytoextraction of Cd and phytostabilization of other potentially toxic metals (Pb, Cr, and Co) from FA lagoon. All the plants were tolerant to Pb pollution (TF > 1, BAF > 1, and BCF > 1); hence, there was a negligible translocation of Pb to the aerial tissues of these plants which shows their suitability in phytostabilization. In addition, V. cinerea accumulated elevated concentration of potentially toxic Cr (50 mg Cr kg-1) and Ni (67 mg Ni kg-1) which could also help in the phytoremediation of FA lagoon.
Status: Active
Global hyperaccumulator database :
Status: Active