Skip to content
naulon

No retraction, correction or concern found when last checked on Oct 20, 2026.

Heavy Metal Stress, Signaling, and Tolerance Due to Plant-Associated Microbes: An Overview

Shalini Tiwari, Charu Lata

Frontiers in Plant Science · 2018 · Review

doi:10.3389/fpls.2018.00452

Abstract

Several anthropogenic activities including mining, modern agricultural practices, and industrialization have long-term detrimental effect on our environment. All these factors lead to increase in heavy metal concentration in soil, water, and air. Soil contamination with heavy metals cause several environmental problems and imparts toxic effect on plant as well as animals. In response to these adverse conditions, plants evolve complex molecular and physiological mechanisms for better adaptability, tolerance, and survival. Nowadays conventional breeding and transgenic technology are being used for development of metal stress resistant varieties which, however, are time consuming and labor intensive. Interestingly the use of microbes as an alternate technology for improving metal tolerance of plants is gaining momentum recently. The use of these beneficial microorganisms is considered as one of the most promising methods for safe crop-management practices. Interaction of plants with soil microorganisms can play a vital role in acclimatizing plants to metalliferous environments, and can thus be explored to improve microbe-assisted metal tolerance. Plant-associated microbes decrease metal accumulation in plant tissues and also help to reduce metal bioavailability in soil through various mechanisms. Nowadays, a novel phytobacterial strategy, i.e., genetically transformed bacteria has been used to increase remediation of heavy metals and stress tolerance in plants. This review takes into account our current state of knowledge of the harmful effects of heavy metal stress, the signaling responses to metal stress, and the role of plant-associated microbes in metal stress tolerance. The review also highlights the challenges and opportunities in this continued area of research on plant-microbe-metal interaction.

Full text

From PubMed Central, U.S. National Library of Medicine, as current on Oct 20, 2026. Paragraph numbers are ours, so an answer can point at one.

Introduction

Heavy metal stress has become a major concern in various terrestrial ecosystems worldwide. Nowadays extensive industrialization imparts detrimental effects on soil as well as on crop productivity by accumulating heavy metals. Damage to soil texture, i.e., pH of soil, presence of different elements, and accumulation of heavy metals cause direct and/or indirect reduction of plant growth by adversely affecting various physiological and molecular activities of plants. Heavy metals such as Zn, Cu, Mo, Mn, Co, and Ni are essential for crucial biological processes and developmental pathways. However, these metals along with four other highly toxic heavy metals including, arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), Cr, Al, and Be can reduce crop productivity to a great extent when their concentration rises beyond supraoptimal values. These toxic elements cause morphological abnormalities, and metabolic disorders that lead to yield reduction in plants. These abnormalities also give rise to the production of reactive oxygen species (ROS), e.g., superoxide anion radical (O2-), H2O2, and hydroxyl radical (OH-), resulting in disruption of the redox homeostasis of cells. This redox status misbalance is known to be a major cause of heavy metal toxicity in plants. Earlier studies reported the negative impact of accumulation of heavy metals in food crops on human health. To withstand heavy metal stress and metal toxicity, plants have evolved numerous defense mechanisms viz reduced heavy metal uptake, sequestration of metal into vacuoles, binding to phytochelatins/metallothioneins, and activation of various antioxidants.

To decipher regulatory networks involved in response to heavy metal tolerance in plants, various omics approaches such as transcriptomics, proteomics, and metabolomics are being routinely used. In combination with different functional genomic approaches, the abovementioned omics approaches help to develop improved varieties with enhanced abiotic stress tolerance. Several quantitative trait loci (QTLs) and candidate genes have been identified for zinc, iron, and Cd tolerance in various plant species which can be utilized for crop improvement by marker-assisted selection or QTL pyramiding. Several previous studies have also reported improvement in heavy metal stress tolerance of plants by genetic engineering. Further, since plant breeding and genetic engineering is a labor intensive and time consuming process, there is a need to develop newer strategies or techniques that would be helpful for sustained crop production and productivity under heavy metal stress. Plant-associated microbes could be used as an alternate strategy for sustainable agricultural production. Numerous plant-associated microbes namely, bacteria and fungi are known to exhibit plant-growth promoting traits under heavy metal stress. These microbes impart favorable effects on plants via several direct and indirect mechanisms such as biofilm formation, siderophores, exopolysaccharide, and phytohormones production. Since microbial heavy metal remediation does not involve any transgenic modifications, it is ethically and societally acceptable. Even though heavy metal tolerance in plants through microbial remediation has been investigated for many years, there is still considerable interest in extensive studies on plant–microbe–metal association due to their direct effects on enhanced biomass production and heavy metal tolerance. This review thus summarizes the recent advances in plant-associated microbes in metal remediation and stress tolerance in plants.

Plant Growth Under the Influence of Highly Toxic Metals

Among numerous heavy metals, four heavy metals As, Pb, Cd, and Hg are considered as the most toxic metals by the Agency for Toxic Substances and Disease Registry, based on their toxicity, frequency of occurrence, and most importantly, their exposure potential to flora and fauna. Origin and impact of these four heavy metals on environment and plant growth are briefly described below.

Arsenic

Arsenic is a naturally occurring metal which pose serious health hazards to millions of people across the globe. It is usually originated via volcanic action, erosion of rocks, and by human activities such as applications of pesticides and wood preservatives, mining and smelting operations. The contamination of As in groundwater used for irrigation and drinking is a worldwide problem as it not only affects crop productivity, but also accumulates in different plant tissues including grains and contaminates food chain. Recently, several studies have been carried out to investigate the physiological and molecular mechanisms of As toxicity, accumulation, detoxification, and tolerance in various plants including rice, lettuce, spinach, and carrot. Inorganic arsenate As(V) and arsenite As(III) are two forms of As that exist in the environment. Both As(III) and As(V) are toxic and are regarded as major environmental pollutants based on United States Environmental Protection Agency (USEPA) evaluation. As(III) is more toxic than As(V) and act by interrupting biological functions in plants via different manner as, for example, it binds to proteins with sulfhydryl groups, interfering with their functions. It also generates ROS, inhibits respiration by binding to vicinal thiols in pyruvate dehydrogenase and 2-oxo-glutarate dehydrogenase, and act indirectly as a mutagen by inducing intrachromosomal homologous recombination. On the other hand, in plants, As(V) interferes with oxidative phosphorylation and ATP synthesis during energy metabolism.

Lead

Lead is one of the most widely and evenly distributed trace metals that exist in various forms in the natural sources. It can affect soil, flora, and fauna health by contaminations from leaded fuels, dust, old lead plumbing pipes, various industrial sites, or even old orchard sites in production where lead arsenate is used. Pb2+ is non-biodegradable and its long-term exposure is found to be acutely toxic to both plants and animals and has several harmful effects on biological systems including soil properties [e.g., pH, organic carbon, amorphous iron, and aluminum oxides (FEAL), and cation exchange capacity;; ]. If proper remedial action not taken, high soil Pb levels may never return to normal. Pb impairs various biological processes in plants including seed germination, seedling development, root elongation, transpiration, chlorophyll biosynthesis, and cell division. It also changes cell membrane permeability by reacting with active groups of different metabolic enzymes, with the phosphate groups of ADP or ATP, and by replacing essential ions, thus causing phytotoxicity. Pb toxicity leads to inhibition of ATP production, induces lipid peroxidation, and DNA damage by over production of ROS.

Cadmium

Cadmium is considered to be one of the most phytotoxic heavy metals. Since it is highly soluble in water, it is easily taken up by plants representing the main entry pathway into the food chain causing serious human health hazards. Cd has been classified as a potent human carcinogen by The International Agency for Research on Cancer. Interestingly, it has reported that it is commonly released into the arable soil from industrial processes and farming practices and also that crops are the main source of Cd intake by humans. Even at low concentrations Cd can severely alter several enzyme activities including those involved in the Calvin cycle, carbohydrate and phosphorus metabolism, and CO2 fixation ultimately resulting in stunted growth, chlorosis, leaf epinasty, alterations in chloroplast ultrastructure, inhibition of photosynthesis and pollen germination and tube growth, induction of lipid peroxidation, and alterations in nitrogen (N) and sulfur (S) metabolism and disruption of antioxidant machinery.

Mercury

Mercury is a natural component of the Earth’s crust that accumulates in land and water ecosystems, mainly as a consequence of different anthropological actions such as mining and industrial activities. The large input of Hg into the arable lands has resulted in the widespread occurrence of Hg-contamination in the entire food chain. In the environment several forms of Hg exist such as elemental (Hg0), inorganic (Hg2+), associated with ions (HgS, ClHg2, Hg2Cl2), and organic (CH3-Hg) but in agricultural soils the ionic form is predominant (Hg2+). Increasing evidence has shown that Hg2+ can readily accumulate in higher plants. At lower concentrations Hg2+ may not significantly affect plant growth but at higher concentrations it becomes highly phytotoxic to plant cells and can cause visible injuries and physiological disorders. Binding of Hg2+ to water channel proteins leads to leaf stomata closure and physical impediment of water flow in plants. Additionally, it has also been reported to interfere with mitochondrial activity. Mercuric ions are further reported to induce oxidative stress by stimulating generation of ROS in plants leading to disruption of biomembrane lipids and cellular metabolism, as well as increased activities of antioxidant enzymes like SOD, POD, or APX indicating the degree of stress.

Heavy Metal Signaling and Tolerance in Plants

In the last few decades, the research areas pertaining to plant responses and tolerance to heavy metal stress have rapidly progressed. Several genes that are induced under metal stress have been identified through various omics approaches as, for example, transcriptome analysis in different plants including Arabidopsis, Brassica, and Lycopersicum revealed role of several transcription factors (TFs) such as bHLH, bZIP, AP2/ERF, and DREB under heavy metal stress. Use of various proteomics techniques such as 2-D electrophoresis, MALDI-TOF, LC-MS have led to the discovery target proteins that take part in heavy metal detoxification in several plants including Oryza sativa, Zea mays, Arabidopsis, and Populus sp.. Similarly, various amino acids, amines, organic acids, phenol, glutathione, and α-tocopherol are some metabolites which have been reported to be involved under heavy metal stress tolerance. However, the functions of several of them are still not known owing to the complexity in plant responses to these stresses. Heavy metal stress signal transduction is initiated by receptors/ion channels by perception of stress signal(s) and further by non-protein messengers such as cyclic nucleotides, calcium, and hydrogen ions (Figure 1). Several kinases and phosphatases relay the stress signals that further leads to gene expression of various TFs and synthesis of metal-detoxifying peptides. Heavy metal(s) activates distinct signaling pathways in plants such as calcium-dependent signaling, mitogen-activated protein kinase signaling, ROS signaling, and hormone signaling that enhance the expression of TFs and/or stress-responsive genes. Diverse Ca2+ sensors such as calmodulins (CaMs), CaM-like proteins, calcineurin B-like proteins (CBLs), and Ca2+-dependent protein kinases (CDPKs) exist in plants that sense, decode, and convey the alterations in cytosolic Ca2+ concentration for the stress response. Transcript profiling of rice roots exposed to long-term and short-term Cr stress suggested the involvement of CDPKs as their activity increased with increasing Cr(VI) concentration. In foxtail millet, Ca2+ activates antioxidant enzymes and provides tolerance against Cr stress. Similarly, MAPKs signaling cascade phosphorylate numerous TFs such as ABRE, DREB, bZIP, MYB, MYC, NAC, and WRKY thus influencing metal stress response. High levels of Cu and Cd are known to activate distinct MAPKs in Medicago sativa. Similarly, Cd induces OsMAPK2 and myelin basic protein (MBP) kinase gene in rice. Several studies have also suggested heavy metal-mediated MAPKs activation via ROS generation, accumulation, and alteration in antioxidant system in Arabidopsis and rice. ROS are also known to disrupt various phytohormone signaling pathways including auxin, ethylene, and JA. A recent study demonstrated that JA exposure improved antioxidant response leading to Cd stress tolerance in rice. Comparative transcriptome analysis of As(III)-treated rice seedlings suggested modulation of signal transduction, plant defense, and hormonal signaling processes such as ABA metabolism. The above observations clearly suggest that variation in the levels of phytohormones change plant response to metal stress.

Several reports also indicate the role of signaling molecules in providing plant-associated-beneficial microbes-mediated abiotic stress tolerance in plants as, for example, MAPK5 was found to be differentially expressed in rice roots treated with Bacillus amyloliquefaciens, a plant growth promoting rhizobacteria (PGPR) under salt stress indicating the induction of MAPKs signaling in presence of PGPR in plants. Altered expression of At3g57530 responsible for calcium- and CaM-dependent protein kinase activity was reported in Arabidopsis under Pseudomonas putida and Pseudomonas fluorescens treatment. The expression of several downstream stress-responsive TFs such as MYB, NAC, and bZIP were also found to be modulated by PGPR treatment in several plants including rice, chickpea, and Arabidopsis. Role of phytohormones ABA, SA, JA, and ethylene have also been elucidated in PGPR inoculated plants under stressed conditions. The induction of these genes which are central to heavy metal stress signaling, in the presence of plant-associated microbes as well indicate the complex cross-talk between plant, microbes, and heavy metals in stress response and tolerance. Therefore, an understanding of the intricate metal stress signaling pathways and the existing cross-talk among the networks of plant–microbe–metal interaction is extremely important to elucidate the stress-responsive networks in plants.

Microbial Remediation of Heavy Metals for Plant Growth Promotion

Remediation of heavy metals is necessary for the protection and conservation of the environment. For the elimination of heavy metals from the environment, numerous physicochemical and biological techniques have been adopted. Physicochemical techniques are rapid but are regarded as challenging due to the cost involved and technical complexity. They also cause adverse effects on soil physical, chemical, and biological properties, and lead to secondary pollution. On the other hand, biological remediation is considered as the most effective method of toxic metal removal as these are natural, environment friendly, low cost, and high societal acceptance technologies. One such technology is the use of plant growth promoting microbes for bioremediation of heavy metal polluted soil and is quite important in the context of global climate change and excessive fertilizer use in agricultural soils. Microbes are known for enhancement of plant growth and survival under heavy metal stress condition as they have the capability of consuming waste and converting the complex waste into simple non-toxic by products/compounds. This is feasible because microorganisms have developed many resistance mechanisms for survival in the presence of toxic heavy metals in their environment. Microbes also enhance bioavailability of metals from soil by chelation, acidification, and precipitation as, for example, organic acids released by microbes and plant roots lower the soil pH and helps in sequestration of metal ions. Microbial remediation processes via plant-associated microbes involved in heavy metal removal is represented in Figure 2. These resistance mechanisms developed by microbes include metal sorption, bioaccumulation, and enzymatic oxidation or reduction to a non-toxic form, and efflux of heavy metals from the cell. Here we have provided a list of recently studied plant-associated microbes that respond to various metal stress in plants (Table 1).

Remediation of Heavy Metals by Bacteria

Bacteria are the most crucial microbial organisms used for the remediation of heavy metal contaminated soils. Bacteria alleviate heavy metal ion toxicity by immobilizing, mobilizing, uptake, and transformation of heavy metals. Moreover, numerous free-living as well as symbiotic PGPR resides in the soil environment around plant root that can positively alter plant growth and its productivity by the production of growth regulators via supplying and facilitating nutrient uptake from soil. Several studies have been reported where PGPR act as potential elicitors for abiotic stress tolerance including heavy metal tolerance. They limit bioavailability of metals by forming complexes with siderophores, particular metabolites, and bacterial transporters. These microorganisms of agronomic importance have evolved various mechanisms to avoid heavy metal stress including: (a) transport of metals across cytoplasmic membrane; (b) biosorption and bioaccumulation to the cell walls; (c) metal entrapment in the extracellular capsules; (d) heavy metals precipitation; and (e) metal detoxification via oxidation–reduction. Heavy-metal-tolerant PGPR including Bacillus, Pseudomonas, Streptomyces, and Methylobacterium have the potential to improve growth and production of crops by reducing the detrimental effects of heavy metals. Previous study reported Cd resistant Ochrobactrum sp. and Pb and As resistant Bacillus spp. have several PGPR traits that help in bioremediation and growth promotion of a rice cultivar. Different rhizobacteria also have been reported that take part in metal accumulation and helps hyperaccumulating plants in uptake of heavy metals and their tolerance. Further, it has been reported that use of microbes with some additives for the plants grown in heavy metal polluted soil are more beneficial than without additives. A recent study showed that addition of thiosulfate with metal-tolerant microbes enhanced mobilization and uptake of As and Hg in Brassica juncea and Lupinus albus promoting bioavailability and phytoextraction. These methods can aid both the biocontrol and bioremediation process simultaneously in polluted soils.

In spite of these practices, nowadays, the use of genetically transformed bacteria in heavy metal bioremediation is gaining great consideration; however, this limited to laboratory trials only. Symbiotic relationship between plants and genetically transformed bacteria helps in in situ bioremediation of organic pollutants. However, only a few evidences are available that highlights the remediation of heavy metals through such symbiotic associations. Examples of few genetically engineered PGPR are listed in Table 2. Recently elimination of toxic metals through a novel phytobacterial strategy, i.e., via use of genetically transformed PGPR has been suggested. Genetically transformed bacteria possess one or more genes to increase remediation of heavy metals. In this context, genes for metal chelators, metal homeostasis, transporters, biodegradative enzymes, metal uptake regulators, and biotic and abiotic stress tolerance are important candidates for making recombinant bacteria.

Remediation of Heavy Metals by Fungi

Numerous filamentous fungi belonging to the genera Trichoderma, Penicillium, Aspergillus, and Mucor have been described as having the ability to tolerate heavy metal stress. Fungal cell walls have excellent metal binding properties due to presence of negative charge on the different functional groups, e.g., carboxylic, amine or sulfhydryl, phosphate, in different wall components. A study showed interaction of Aspergillus niger var. tubingensis Ed8 with Cr(VI) mainly in a reduction process and also in a sorption process. Previous studies reported reduction in As induced stress in chickpea through Trichoderma sp..

Arbuscular mycorrhizal fungi (AMF) are also one of the most prominent soil microorganisms. They establish direct physical link between soil and plant roots which increase root surface area facilitating nutrient absorption by the plants. AM fungi are also involved in alleviating metal toxicity to the host plant. The specific role of arbuscular mycorrhizae in the host plant on exposure to heavy metal depends on a variety of factors, including the plant species and ecotype, the fungal species and ecotype, the metal and its availability; soil edaphic conditions, including soil fertility; and plant growth conditions, such as light intensity or root density. Similar to PGPR, several mechanisms have been hypothesized for toxic metal direction and allocation in plant roots in the presence of AMF including (a) heavy metals bound to cell wall and deposit in the vacuoles of AMF, (b) metal sequestration by the help of siderophores in the soil or into root apoplasm, (c) metals bound to metallothioneins or phytochelatins inside the fungal or plant cells, and (d) metal transporters at the tonoplast of both plants and fungi catalyze the transport of metals from cytoplasm.

Conclusion and Future Perspectives

Heavy metal contamination and remediation has received considerable attention in today’s world owing to the fact that several heavy metals cannot be degraded and hence persist in the soil. Several strategies have been successfully applied to generate plants which are able to grow in metal contaminated soils and accumulate or tolerate metal stress. Use of microbial approach for heavy metal tolerance and remediation is an eco-friendly and economic approach. Since the plant heavy metal uptake and tolerance depend on various factors, interactions between plant and microbes can play an important role in successful survival and growth of plants in contaminated soils. Plant growth promoting microbes also assist plant growth by changing bioavailability of heavy metal. These beneficial effects exhibited by microbes, together with the suggested interrelationship between heavy metal tolerance and plant growth promoting ability, indicates that their exploitation in remediating metal contaminated soils might have significant potential in near future. In spite of these practices, genetically engineered microbes also have been used for remediation processes. Undoubtedly these engineered microbes have greater remediation potential but their impact on ecosystems needs to be elucidated before commercialization. Despite several findings to date, various steps of regulatory networks via plant-associated microbes in heavy metal stress are still unknown, and more investigations need to be done for unraveling the cross-talk among soil-microbe and metal interaction in different crops. Additionally, synergistic action of plant and microbe and their mechanism for metal mobilization, transformation, and detoxification should also be studied. Further monitoring and managing microbial heavy metal remediation requires the characterization of the fate and behavior of the compounds of interest in the environment. However, at present, it is difficult to understand the environmental impacts of various metals mostly as a consequence of insufficient information being available about them. Thus this highlights the importance of a consistent link between research and development for the assessment and treatment of emerging metal pollutants and the tools, equipment and knowhow that contributes toward the fulfillment of these challenges.

Author Contributions

ST and CL wrote and reviewed the manuscript.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References 152

  1. 1.

    Adediran G. A. Ngwenya B. T. Mosselmans J. F. W. Heal K. V. Harvie B. A. (2015 ). Mechanism behind bacteria induced plant growth promotion and Zn accumulation in Brassica juncea. J. Hazard. Mater. 283 490–499.

    Not in our library10.1016/j.jhazmat.2014.09.064

  2. 2.

    Ahemad M. (2012 ). Implication of bacterial resistance against heavy metals in bioremediation: a review. J. Inst. Integr. Omics Appl. Biotechnol. 3 39–46.

    Not in our library

  3. 3.

    Ahmad I. Akhtar M. J. Asghar H. N. Ghafoor U. Shahid M. (2016 ). Differential effects of plant growth-promoting Rhizobacteria on maize growth and cadmium uptake. J. Plant Growth Regul. 35 303–315.

    Not in our library10.1007/s00344-015-9534-5

  4. 4.

    Ali H. Khan E. Sajad M. A. (2013 ). Phytoremediation of heavy metals-Concepts and applications. Chemosphere 91 869–881.

    Not in our library10.1016/j.chemosphere.2013.01.075

  5. 5.

    Amari T. Ghnaya T. Abdelly C. (2017 ). Nickel, cadmium and lead phytotoxicity and potential of halophytic plants in heavy metal extraction. S. Afr. J. Bot. 111 99–110.

    Not in our library10.1016/j.sajb.2017.03.011

  6. 6.

    Arora K. Sharma S. Monti A. (2016 ). Bio-remediation of Pb and Cd polluted soils by switch grass: a case study in India. Int. J. Phytoremediation 18 704–709.

    Not in our library10.1080/15226514.2015.1131232

  7. 7.

    Ashraf M. A. Hussain I. Rasheed R. Iqbal M. Riaz M. Arif M. S. (2017 ). Advances in microbe-assisted reclamation of heavy metal contaminated soils over the last decade: a review. J. Environ. Manage. 198 132–143.

    Not in our library10.1016/j.jenvman.2017.04.060

  8. 8.

    ATSDR (2003 ). Agency for Toxic Substances and Disease Registry. Available at: http://www.atsdr.cdc.gov/

    Not in our library

  9. 9.

    Azcón R. Perálvarez M. D. C. Roldán A. Barea J. M. (2010 ). Arbuscular mycorrhizal fungi, Bacillus cereus, and Candida parapsilosis from a multicontaminated soil alleviate metal toxicity in plants. Microb. Ecol. 59 668–677.

    Not in our library10.1007/s00248-009-9618-5

  10. 10.

    Azevedo R. Rodriguez E. (2012 ). Phytotoxicity of mercury in plants: a review. J. Bot. 2012:848614

    Not in our library10.1155/2012/848614

  11. 11.

    Babu A. G. Kim J. D. Oh B. T. (2013 ). Enhancement of heavy metal phytoremediation by Alnus firma with endophytic Bacillus thuringiensis GDB-1. J. Hazard. Mater. 250 477–483.

    Not in our library10.1016/j.jhazmat.2013.02.014

  12. 12.

    Belimov A. A. Puhalsky I. V. Safronova V. I. Shaposhnikov A. I. Vishnyakova M. A. Semenova E. V. (2015 ). Role of plant genotype and soil conditions in symbiotic plant-microbe interactions for adaptation of plants to cadmium-polluted soils. Water Air Soil Pollut. 226:264

    Not in our library10.1007/s11270-015-2537-9

  13. 13.

    Bradham K. D. Dayton E. A. Basta N. T. Schroder J. Payton M. Lanno R. P. (2006 ). Effect of soil properties on lead bioavailability and toxicity to earthworms. Environ. Toxicol. Chem. 25 769–775.

    Not in our library10.1897/04-552r.1

  14. 14.

    Buchet J. P. Lauwerys R. Roels H. Bernard A. Bruaux P. Claeys F. (1990 ). Renal effects of cadmium body burden of the general population. Lancet 336 699–702.

    Not in our library10.1016/0140-6736(90)92201-r

  15. 15.

    Carbonell A. A. Aarabi M. A. Delaune R. D. Grambrell R. P. Patrick W. H. (1998 ). Arsenic in wetland vegetation: availability, phytotoxicity, uptake and effects on plants growth and nutrition. Sci. Total Environ. 217 189–199.

    Not in our library10.1016/s0048-9697(98)00195-8

  16. 16.

    Cargnelutti D. Tabaldi L. A. Spanevello R. M. de Oliveira Jucoski G. Battisti V. Redin M. (2006 ). Mercury toxicity induces oxidative stress in growing cucumber seedlings. Chemosphere 65 999–1006.

    Not in our library10.1016/j.chemosphere.2006.03.037

  17. 17.

    Chakrabarty D. Trivedi P. K. Misra P. Tiwari M. Shri M. Shukla D. (2009 ). Comparative transcriptome analysis of arsenate and arsenite stresses in rice seedlings. Chemosphere 74 688–702.

    Not in our library10.1016/j.chemosphere.2008.09.082

  18. 18.

    Chen L. Luo S. Li X. Wan Y. Chen J. Liu C. (2014 ). Interaction of Cd hyperaccumulator Solanum nigrum L. and functional endophyte Pseudomonas sp. Lk9 on soil heavy metals uptake. Soil Biol. Biochem. 68 300–308.

    Not in our library10.1016/j.soilbio.2013.10.021

  19. 19.

    Chen M. Xu P. Zeng G. Yang C. Huang D. Zhang J. (2015 ). Bioremediation of soils contaminated with polycyclic aromatic hydrocarbons, petroleum, pesticides, chlorophenols and heavy metals by composting: applications, microbes and future research needs. Biotechnol. Adv. 33 745–755.

    Not in our library10.1016/j.biotechadv.2015.05.003

  20. 20.

    Collin V. C. Eymery F. Genty B. Rey P. Havaux M. (2008 ). Vitamin E is essential for the tolerance of Arabidopsis thaliana to metal-induced oxidative stress. Plant Cell Environ. 31 244–257.

    Not in our library10.1111/j.1365-3040.2007.01755.x

  21. 21.

    Conde A. Chaves M. M. Geros H. (2011 ). Membrane transport, sensing and signaling in plant adaptation to environmental stress. Plant Cell Physiol. 52 1583–1602.

    Not in our library10.1093/pcp/pcr107

  22. 22.

    Coreño-Alonso A. Solé A. Diestra E. Esteve I. Gutiérrez-Corona J. F. López G. R. (2014 ). Mechanisms of interaction of chromium with Aspergillus niger var. tubingensis strain Ed8. Bioresour. Technol. 158 188–192.

    Not in our library10.1016/j.biortech.2014.02.036

  23. 23.

    Courbot M. Willems G. Motte P. Arvidsson S. Roosens N. Saumitou-Laprade P. (2007 ). A major quantitative trait locus for cadmium tolerance in Arabidopsis halleri colocalizes with HMA4, a gene encoding a heavy metal ATPase. Plant Physiol. 144 1052–1065.

    Not in our library10.1104/pp.106.095133

  24. 24.

    Dąbrowska G. Hrynkiewicz K. Trejgell A. Baum C. (2017 ). The effect of plant growth-promoting rhizobacteria on the phytoextraction of Cd and Zn by Brassica napus L. Int. J. Phytoremediation 19 597–604.

    Not in our library10.1080/15226514.2016.1244157

  25. 25.

    Dary M. Chamber-Pérez M. A. Palomares A. J. Pajuelo E. (2010 ). “In situ” phytostabilisation of heavy metal polluted soils using Lupinus luteus inoculated with metal resistant plant-growth promoting rhizobacteria. J. Hazard. Mater. 177 323–330.

    Not in our library10.1016/j.jhazmat.2009.12.035

  26. 26.

    Doble M. Kumar A. (2005 ). Biotreatment of Industrial Effluents. Oxford: Butterworth-Heinemann 19–38.

    Not in our library10.1016/b978-075067838-4/50004-x

  27. 27.

    Dubey S. Shri M. Misra P. Lakhwani D. Bag S. K. Asif M. H. (2014 ). Heavy metals induce oxidative stress and genome-wide modulation in transcriptome of rice root. Funct. Integr. Genomics 14 401–417.

    Not in our library10.1007/s10142-014-0361-8

  28. 28.

    Eapen S. D’Souza S. F. (2005 ). Prospects of genetic engineering of plants for phytoremediation of toxic metals. Biotechnol. Adv. 23 97–114.

    Not in our library10.1016/j.biotechadv.2004.10.001

  29. 29.

    Ezzouhri L. Castro E. Moya M. Espinola F. Lairini K. (2009 ). Heavy metal tolerance of filamentous fungi isolated from polluted sites in Tangier, Morocco. Afr. J. Microbiol. Res. 3 35–48.

    Not in our library

  30. 30.

    Fang H. Jing T. Liu Z. Zhang L. Jin Z. Pei Y. (2014 ). Hydrogen sulfide interacts with calcium signaling to enhance the chromium tolerance in Setaria italica. Cell Calcium 56 472–481.

    Not in our library10.1016/j.ceca.2014.10.004

  31. 31.

    Farinati S. Dalcorso G. Varotto S. Furini A. (2010 ). The Brassica juncea BjCdR15, an ortholog of Arabidopsis TGA3, is a regulator of cadmium uptake, transport and accumulation in shoots and confers cadmium tolerance in transgenic plants. New Phytol. 185 964–978.

    Not in our library10.1111/j.1469-8137.2009.03132.x

  32. 32.

    Franchi E. Rolli E. Marasco R. Agazzi G. Borin S. Cosmina P. (2017 ). Phytoremediation of a multi contaminated soil: mercury and arsenic phytoextraction assisted by mobilizing agent and plant growth promoting bacteria. J. Soils Sediments 17 1224–1236.

    Not in our library10.1007/s11368-015-1346-5

  33. 33.

    François F. Lombard C. Guigner J. M. Soreau P. Brian-Jaisson F. Martino G. (2012 ). Isolation and characterization of environmental bacteria capable of extracellular biosorption of mercury. Appl. Environ. Microbiol. 78 1097–1106.

    Not in our library10.1128/aem.06522-11

  34. 34.

    Gao Y. Miao C. Mao L. Zhou P. Jin Z. Shi W. (2010 ). Improvement of phytoextraction and antioxidative defense in Solanum nigrum L. under cadmium stress by application of cadmium-resistant strain and citric acid. J. Hazard. Mater. 181 771–777.

    Not in our library10.1016/j.jhazmat.2010.05.080

  35. 35.

    Garg N. Aggarwal N. (2011 ). Effects of interactions between cadmium and lead on growth, nitrogen fixation, phytochelatin, and glutathione production in mycorrhizal Cajanus cajan (L.) Millsp. J. Plant Growth Regul. 30 286–300.

    Not in our library10.1007/s00344-010-9191-7

  36. 36.

    Gianazza E. Wait R. Sozzi A. Regondi S. Saco D. Labra M. (2007 ). Growth and protein profile changes in Lepidium sativum L. plantlets exposed to cadmium. Environ. Exp. Bot. 59 179–187.

    Not in our library10.1016/j.envexpbot.2005.12.005

  37. 37.

    Gill S. S. Tuteja N. (2010 ). Reactive oxygen species and antioxidant machinery in abiotic stress tolerance in crop plants. Plant Physiol. Biochem. 48 909–930.

    Not in our library10.1016/j.plaphy.2010.08.016

  38. 38.

    Gill S. S. Tuteja N. (2011 ). Cadmium stress tolerance in crop plants: probing the role of sulfur. Plant Signal. Behav. 6 215–222.

    Not in our library10.4161/psb.6.2.14880

  39. 39.

    Glick B. R. (2003 ). Phytoremediation: synergistic use of plants and bacteria to clean up the environment. Biotechnol. Adv. 21 383–393.

    Not in our library10.1016/s0734-9750(03)00055-7

  40. 40.

    Glick B. R. (2010 ). Using soil bacteria to facilitate phytoremediation. Biotechnol. Adv. 28 367–374.

    Not in our library10.1016/j.biotechadv.2010.02.001

  41. 41.

    Gontia-Mishra I. Sapre S. Sharma A. Tiwari S. (2016 ). Alleviation of mercury toxicity in wheat by the interaction of mercury-tolerant plant growth-promoting rhizobacteria. J. Plant Growth Regul. 35 1000–1012.

    Not in our library10.1007/s00344-016-9598-x

  42. 42.

    Gupta S. Singh D. (2017 ). “Role of genetically modified microorganisms in heavy metal bioremediation,” in Advances in Environmental Biotechnology eds Kumar R. Sharma A. Ahluwalia S. (Singapore: Springer) 197–214.

    Not in our library

  43. 43.

    Hansda A. Kumar V. (2017 ). Cu-resistant Kocuria sp. CRB15: a potential PGPR isolated from the dry tailing of Rakha copper mine. 3 Biotech. 7:132.

    Not in our library10.1007/s13205-017-0757-y

  44. 44.

    Hassan T. U. Bano A. Naz I. (2017 ). Alleviation of heavy metals toxicity by the application of plant growth promoting rhizobacteria and effects on wheat grown in saline sodic field. Int. J. Phytoremediation 19 522–529.

    Not in our library10.1080/15226514.2016.1267696

  45. 45.

    He H. Ye Z. Yang D. Yan J. Xiao L. Zhong T. (2013 ). Characterization of endophytic Rahnella sp. JN6 from Polygonum pubescens and its potential in promoting growth and Cd, Pb, Zn uptake by Brassica napus. Chemosphere 90 1960–1965.

    Not in our library10.1016/j.chemosphere.2012.10.057

  46. 46.

    Helleday T. Nilsson R. Jenssen D. (2000 ). Arsenic (III) and heavy metal ions induce intrachromosomal homologous recombination in the hprt gene of V79 Chinese hamster cells. Environ. Mol. Mutagen. 35 114–122.

    Not in our library10.1002/(sici)1098-2280(2000)35:2<114::aid-em6>3.0.co;2-q

  47. 47.

    Hrynkiewicz K. Baum C. (2014 ). “Application of microorganisms in bioremediation of environment from heavy metals,” in Environmental Deterioration and Human Health eds Malik A. Grohmann E. Akhtar R. (Dordrecht: Springer) 215–227.

    Not in our library

  48. 48.

    Huang T. L. Huang L. Y. Fu S. F. Trinh N. N. Huang H. J. (2014 ). Genomic profiling of rice roots with short-and long-term chromium stress. Plant Mol. Biol. 86 157–170.

    Not in our library10.1007/s11103-014-0219-4

  49. 49.

    IARC (1993 ). IARC Monographs on the Evaluation of Carcinogenic Risk to Humans. Beryllium, Cadmium, Mercury and Exposures in the Glass Manufacturing Industry Vol. 58 Lyon: International Agency for Research on Cancer Publication 41–117.

    Not in our library

  50. 50.

    Ibrahim M. A. Khan P. R. Hegazy S. S. Hashim E. A. Azamal H. Ansari M. K. A. (2015 ). Improving the phytoextraction capacity of plants to scavenge heavy-metal infested sites. Environ. Rev. 23 1–22.

    Not in our library

  51. 51.

    Ike A. Sriprang R. Ono H. Murooka Y. Yamashita M. (2007 ). Bioremediation of cadmium contaminated soil using symbiosis between leguminous plant and recombinant rhizobia with the MTL4 and the PCS genes. Chemosphere 66 1670–1676.

    Not in our library10.1016/j.chemosphere.2006.07.058

  52. 52.

    Ike A. Sriprang R. Ono H. Murooka Y. Yamashita M. (2008 ). Promotion of metal accumulation in nodule of Astragalus sinicus by the expression of the iron-regulated transporter gene in Mesorhizobium huakuii subsp. rengei B3. J. Biosci. Bioeng. 105 642–648.

    Not in our library10.1263/jbb.105.642

  53. 53.

    Islam E. Khan M. T. Irem S. (2015 ). Biochemical mechanisms of signalling: perspectives in plant under arsenic stress. Ecotoxicol. Environ. Saf. 114 126–133.

    Not in our library10.1016/j.ecoenv.2015.01.017

  54. 54.

    Israr M. Sahi S. Datta R. Sarkar D. (2006 ). Bioaccumulation and physiological effects of mercury in Sesbania drummondii. Chemosphere 65 591–598.

    Not in our library10.1016/j.chemosphere.2006.02.016

  55. 55.

    Jamil M. Zeb S. Anees M. Roohi A. Ahmed I. ur Rehman S. (2014 ). Role of Bacillus licheniformis in phytoremediation of nickel contaminated soil cultivated with rice. Int. J. Phytoremediation 16 554–571.

    Not in our library10.1080/15226514.2013.798621

  56. 56.

    Jan S. Parray J. A. (eds). (2016 ). “Use of mycorrhiza as metal tolerance strategy in plants,” in Approaches to Heavy Metal Tolerance in Plants (Singapore: Springer) 57–68.

    Not in our library10.1007/978-981-10-1693-6_4

  57. 57.

    Järup L. (2003 ). Hazards of heavy metal contamination. Br. Med. Bull. 68 167–182.

    Not in our library10.1093/bmb/ldg032

  58. 58.

    Jonak C. Nakagami H. Hirt H. (2004 ). Heavy metal stress. Activation of distinct mitogen-activated protein kinase pathways by copper and cadmium. Plant Physiol. 136 3276–3283.

    Not in our library10.1104/pp.104.045724

  59. 59.

    Kamran M. A. Syed J. H. Eqani S. A. Munis M. F. H. Chaudhary H. J. (2015 ). Effect of plant growth-promoting rhizobacteria inoculation on cadmium (Cd) uptake by Eruca sativa. Environ. Sci. Pollut. Res. Int. 22 9275–9283.

    Not in our library10.1007/s11356-015-4074-x

  60. 60.

    Kumar B. Smita K. Flores L. C. (2017 ). Plant mediated detoxification of mercury and lead. Arabian J. Chem. 10 S2335–S2342.

    Not in our library10.1093/pcp/pcu117

  61. 61.

    Kumar S. Dubey R. S. Tripathi R. D. Chakrabarty D. Trivedi P. K. (2015 ). Omics and biotechnology of arsenic stress and detoxification in plants: current updates and prospective. Environ. Int. 74 221–230.

    Not in our library10.1016/j.envint.2014.10.019

  62. 62.

    Kumar S. Trivedi P. K. (2016 ). “Heavy metal stress signaling in plants,” in Plant Metal Interaction- Emerging Remediation Techniques ed. Ahmad P. (Amsterdan: Elsevier) 585–603.

    Not in our library10.1016/b978-0-12-803158-2.00025-4

  63. 63.

    LeDuc D. L. Abdel Samie M. Móntes-Bayon M. Wu C. P. Reisinger S. J. Terry N. (2006 ). Overexpressing both ATP sulfurylase and selenocysteine methyltransferase enhances selenium phytoremediation traits in Indian mustard. Environ. Pollut. 144 70–76.

    Not in our library10.1016/j.envpol.2006.01.008

  64. 64.

    Lermen C. Morelli F. Gazim Z. C. Silva P. A. D. Goncalves J. E. Dragunski D. C. (2015 ). Essential oil content and chemical composition of Cymbopogon citratus inoculated with arbuscular mycorrhizal fungi under different levels of lead. Ind. Crops Prod. 76 734–738.

    Not in our library10.1016/j.indcrop.2015.07.009

  65. 65.

    Leyval C. Turnau K. Haselwandter K. (1997 ). Effect of heavy metal pollution on mycorrhizal colonization and function-physiological, ecological and applied aspects. Mycorrhiza 7 139–153.

    Not in our library10.1007/s005720050174

  66. 66.

    Lin Y. F. Aarts M. G. (2012 ). The molecular mechanism of zinc and cadmium stress response in plants. Cell. Mol. Life Sci. 69 3187–3206.

    Not in our library10.1007/s00018-012-1089-z

  67. 67.
  68. 68.

    Liu H. Yuan M. Tan S. Y. Yang X. P. Lan Z. Jiang Q. Y. (2015 ). Enhancement of arbuscular mycorrhizal fungus (Glomus versiforme) on the growth and Cd uptake by Cd-hyperaccumulator Solanum nigrum. Appl. Soil Ecol. 89 44–49.

    Not in our library10.1016/j.apsoil.2015.01.006

  69. 69.

    Liu X. M. Kim K. E. Kim K. C. Nguyen X. C. Han H. J. Jung M. S. (2010 ). Cadmium activates Arabidopsis MPK3 and MPK6 via accumulation of reactive oxygen species. Phytochemistry 71 614–618.

    Not in our library10.1016/j.phytochem.2010.01.005

  70. 70.

    Luo S. L. Chen L. Chen J. I. Xiao X. Xu T. Y. Wan Y. (2011 ). Analysis and characterization of cultivable heavy metal-resistant bacterial endophytes isolated from Cd hyperaccumulator Solanum nigrum L. and their potential use for phytoremediation. Chemosphere 85 1130–1138.

    Not in our library10.1016/j.chemosphere.2011.07.053

  71. 71.

    Ma Y. Oliviera R. S. Nai F. Rajkumar M. Luo Y. Rocha I. (2015 ). The hyperaccumulator Sedum plumbizincicola harbors metal-resistant endophytic bacteria that improve its phytoextraction capacity in multi-metal contaminated soil. J. Environ. Manage. 156 62–69.

    Not in our library10.1016/j.jenvman.2015.03.024

  72. 72.

    Ma Y. Prasad M. N. V. Rajkumar M. Freitas H. (2011 ). Plant growth promoting rhizobacteria and endophytes accelerate phytoremediation of metalliferous soils. Biotechnol. Adv. 29 248–258.

    Not in our library10.1016/j.biotechadv.2010.12.001

  73. 73.

    Marques A. P. Moreira H. Franco A. R. Rangel A. O. Castro P. M. (2013 ). Inoculating Helianthus annuus (sunflower) grown in zinc and cadmium contaminated soils with plant growth promoting bacteria- Effects on phytoremediation strategies. Chemosphere 92 74–83.

    Not in our library10.1016/j.chemosphere.2013.02.055

  74. 74.

    Meharg A. A. (2003 ). The mechanistic basis of interactions between mycorrhizal associations and toxic metal cations. Mycol. Res. 107 1253–1265.

    Not in our library10.1017/s0953756203008608

  75. 75.

    Meyer C. L. Pauwels M. Briset L. Godé C. Salis P. Bourceaux A. (2016 ). Potential preadaptation to anthropogenic pollution: evidence from a common quantitative trait locus for zinc and cadmium tolerance in metallicolous and nonmetallicolous accessions of Arabidopsis halleri. New Phytol. 212 934–943.

    Not in our library10.1111/nph.14093

  76. 76.
  77. 77.

    Monteiro C. M. Castro P. M. Malcata F. X. (2012 ). Metal uptake by microalgae: underlying mechanisms and practical applications. Biotechnol. Prog. 28 299–311.

    Not in our library10.1002/btpr.1504

  78. 78.

    Montero-Palmero M. B. Ortega-Villasante C. Escobar C. Hernández L. E. (2014 ). Are plant endogenous factors like ethylene modulators of the early oxidative stress induced by mercury? Front. Environ. Sci. 2:34

    Not in our library10.3389/fenvs.2014.00034

  79. 79.

    Mosa K. A. Ismail A. Helmy M. (2017 ). “Functional genomics combined with other omics approaches for better understanding abiotic stress tolerance in plants,” in Plant Stress Tolerance ed. Sunkar and Ramanjulu (Cham: Springer International Publishing) 55–73.

    Not in our library

  80. 80.

    Mustapha M. U. Halimoon N. (2015 ). Screening and isolation of heavy metal tolerant bacteria in industrial effluent. Procedia Environ. Sci. 30 33–37.

    Not in our library10.1016/j.proenv.2015.10.006

  81. 81.

    Nabulo G. Black C. R. Young S. D. (2011 ). Trace metal uptake by tropical vegetables grown on soil amended with urban sewage sludge. Environ. Pollut. 159 368–376.

    Not in our library10.1016/j.envpol.2010.11.007

  82. 82.

    Nadeem S. M. Ahmad M. Zahir Z. A. Javaid A. Ashraf M. (2014 ). The role of mycorrhizae and plant growth promoting rhizobacteria (PGPR) in improving crop productivity under stressful environments. Biotechnol. Adv. 32 429–448.

    Not in our library10.1016/j.biotechadv.2013.12.005

  83. 83.

    Nautiyal C. S. Srivastava S. Chauhan P. S. Seem K. Mishra A. Sopory S. K. (2013 ). Plant growth-promoting bacteria Bacillus amyloliquefaciens NBRISN13 modulates gene expression profile of leaf and rhizosphere community in rice during salt stress. Plant Physiol. Biochem. 66 1–9.

    Not in our library10.1016/j.plaphy.2013.01.020

  84. 84.

    Neumann R. B. Ashfaque K. N. Badruzzaman A. B. M. Ali M. A. Shoemaker J. K. Harvey C. F. (2010 ). Anthropogenic influences on groundwater arsenic concentrations in Bangladesh. Nat. Geosci. 3 46–52.

    Not in our library10.1038/ngeo685

  85. 85.

    Nie L. Shah S. Rashid A. Burd G. I. Dixon D. G. Glick B. R. (2002 ). Phytoremediation of arsenate contaminated soil by transgenic canola and the plant growth-promoting bacterium Enterobacter cloacae CAL2. Plant Physiol. Biochem. 40 355–361.

    Not in our library10.1016/s0981-9428(02)01375-x

  86. 86.

    Oladipo O. G. Awotoye O. O. Olayinka A. Bezuidenhout C. C. Maboeta M. S. (2017 ). Heavy metal tolerance traits of filamentous fungi isolated from gold and gemstone mining sites. Braz. J. Microbiol. 49 29–37.

    Not in our library10.1016/j.bjm.2017.06.003

  87. 87.

    Ong G. H. Ho X. H. Shamkeeva S. Fernando M. S. Shimen A. Wong L. S. (2017 ). Biosorption study of potential fungi for copper remediation from Peninsular Malaysia. Remediat. J. 27 59–63.

    Not in our library10.1002/rem.21531

  88. 88.

    Ortega-Villasante C. Rellán-Álvarez R. Del Campo F. F. Carpena-Ruiz R. O. Hernández L. E. (2005 ). Cellular damage induced by cadmium and mercury in Medicago sativa. J. Exp. Bot. 56 2239–2251.

    Not in our library10.1093/jxb/eri223

  89. 89.

    Pandey S. Ghosh P. K. Ghosh S. De T. K. Maiti T. K. (2013 ). Role of heavy metal resistant Ochrobactrum sp. and Bacillus spp. strains in bioremediation of a rice cultivar and their PGPR like activities. J. Microbiol. 51 11–17.

    Not in our library10.1007/s12275-013-2330-7

  90. 90.

    Panuccio M. R. Sorgona A. Rizzo M. Cacco G. (2009 ). Cadmium adsorption on vermiculite, zeolite and pumice: batch experiment studies. J. Environ. Manage. 90 364–374.

    Not in our library10.1016/j.jenvman.2007.10.005

  91. 91.

    Pawlowska T. E. Charvat I. (2004 ). Heavy-metal stress and developmental patterns of arbuscular mycorrhizal fungi. Appl. Environ. Microbiol. 70 6643–6649.

    Not in our library10.1128/aem.70.11.6643-6649.2004

  92. 92.

    Pehlivan E. Özkan A. M. Dinc S. Parlayici S. (2009 ). Adsorption of Cu2+ and Pb2+ ion on dolomite powder. J. Hazard. Mater. 167 1044–1049.

    Not in our library10.1016/j.jhazmat.2009.01.096

  93. 93.

    Pereira S. I. A. Barbosa L. Castro P. M. L. (2015 ). Rhizobacteria isolated from a metal polluted area enhance plant growth in zinc and cadmium-contaminated soil. Int. J. Environ. Sci. Technol. 12 2127–2142.

    Not in our library10.1007/s13762-014-0614-z

  94. 94.

    Pierart A. Shahid M. Séjalon-Delmas N. Dumat C. (2015 ). Antimony bioavailability: knowledge and research perspectives for sustainable agricultures. J. Hazard. Mater. 289 219–234.

    Not in our library10.1016/j.jhazmat.2015.02.011

  95. 95.

    Pourrut B. Jean S. Silvestre J. Pinelli E. (2011 ). Lead-induced DNA damage in Vicia faba root cells: potential involvement of oxidative stress. Mutat. Res. 726 123–128.

    Not in our library10.1016/j.mrgentox.2011.09.001

  96. 96.

    Pramanik K. Mitra S. Sarkar A. Soren T. Maiti T. K. (2017 ). Characterization of cadmium-resistant Klebsiella pneumoniae MCC 3091 promoted rice seedling growth by alleviating phytotoxicity of cadmium. Environ. Sci. Pollut. Res. 24 24419–24437.

    Not in our library10.1007/s11356-017-0033-z

  97. 97.

    Rajkumar M. Ae N. Prasad M. N. V. Freitas H. (2010 ). Potential of siderophore-producing bacteria for improving heavy metal phytoextraction. Trends Biotechnol. 28 142–149.

    Not in our library10.1016/j.tibtech.2009.12.002

  98. 98.

    Rao K. P. Vani G. Kumar K. Wankhede D. P. Misra M. Gupta M. (2011 ). Arsenic stress activates MAP kinase in rice roots and leaves. Arch. Biochem. Biophys. 506 73–82.

    Not in our library10.1016/j.abb.2010.11.006

  99. 99.

    Román-Ponce B. Reza-vázquez D. M. Gutiérrez-paredes S. María de jesús D. E. Maldonado-hernández J. Bahena-osorio Y. (2017 ). Plant growth-promoting traits in rhizobacteria of heavy metal-resistant plants and their effects on Brassica nigra seed germination. Pedosphere 27 511–526.

    Not in our library10.1016/s1002-0160(17)60347-3

  100. 100.

    Salla V. Hardaway C. J. Sneddon J. (2011 ). Preliminary investigation of Spartina alterniflora for phytoextraction of selected heavy metals in soils from Southwest Louisiana. Microchem. J. 97 207–212.

    Not in our library10.1016/j.microc.2010.09.005

  101. 101.

    Sandalio L. M. Dalurzo H. C. Gomez M. Romero-Puertas M. C. del Rio L. A. (2001 ). Cadmium-induced changes in the growth and oxidative metabolism of pea plant. J. Exp. Bot. 52 2115–2126.

    Not in our library10.1093/jexbot/52.364.2115

  102. 102.

    Satarug S. Baker J. R. Reilly P. E. B. Moore M. R. Williams D. J. (2002 ). Cadmium levels in the lung, liver, kidney cortex and urine samples from Australians without occupational exposure to metals. Arch. Environ. Health 57 69–77.

    Not in our library10.1080/00039890209602919

  103. 103.

    Saxena B. Shukla K. Giri B. (2017 ). “Arbuscular mycorrhizal fungi and tolerance of salt stress in plants,” in Arbuscular Mycorrhizas and Stress Tolerance of Plants ed. Wu Q. S. (Singapore: Springer) 67–97.

    Not in our library10.1007/978-981-10-4115-0_4

  104. 104.

    Sessitsch A. Kuffner M. Kidd P. Vangronsveld J. Wenzel W. W. Fallmann K. (2013 ). The role of plant-associated bacteria in the mobilization and phytoextraction of trace elements in contaminated soils. Soil Biol. Biochem. 60 182–194.

    Not in our library10.1016/j.soilbio.2013.01.012

  105. 105.

    Shahid M. Khalid S. Abbas G. Shahid N. Nadeem M. Sabir M. (2015 ). “Heavy metal stress and crop productivity,” in Crop Production and Global Environmental Issues ed. Hakeem K. R. (Cham: Springer International Publishing) 1–25.

    Not in our library

  106. 106.

    Shameer K. Ambika S. Varghese S. M. Karaba N. Udayakumar M. Sowdhamini R. (2009 ). STIFDB-Arabidopsis stress responsive transcription factor dataBase. Int. J. Plant Genomics 2009:83429.

    Not in our library10.1155/2009/583429

  107. 107.

    Sharma P. Dubey R. S. (2006 ). “Cadmium uptake and its toxicity in higher plants,” in Cadmium Toxicity and Tolerance in Plants eds Khan N. A. Samiullah (New Delhi: Narosa Publishing House) 64–86.

    Not in our library

  108. 108.

    Sheoran V. Sheoran A. Poonia P. (2011 ). Role of hyperaccumulators in phytoextraction of metals from contaminated mining sites: a review. Crit. Rev. Environ. Sci. Technol. 41 168–214.

    Not in our library10.1080/10643380902718418

  109. 109.

    Shin M. Shim J. You Y. Myung H. Bang K. S. Cho M. (2012 ). Characterization of lead resistant endophytic Bacillus sp. MN3-4 and its potential for promoting lead accumulation in metal hyperaccumulator Alnus firma. J. Hazard. Mater. 19 314–320.

    Not in our library10.1016/j.jhazmat.2011.11.010

  110. 110.

    Singh I. Shah K. (2014 ). Exogenous application of methyl jasmonate lowers the effect of cadmium-induced oxidative injury in rice seedlings. Phytochemistry 108 57–66.

    Not in our library10.1016/j.phytochem.2014.09.007

  111. 111.

    Singh J. S. Abhilash P. C. Singh H. B. Singh R. P. Singh D. P. (2011 ). Genetically engineered bacteria: an emerging tool for environmental remediation and future research perspectives. Gene 480 1–9.

    Not in our library10.1016/j.gene.2011.03.001

  112. 112.
  113. 113.

    Sriprang R. Hayashi M. Ono H. Takagi M. Hirata K. Murooka Y. (2003 ). Enhanced accumulation of Cd2+ by a Mesorhizobium sp. transformed with a gene from Arabidopsis thaliana coding for phytochelatin synthase. Appl. Environ. Microbiol. 69 1791–1796.

    Not in our library10.1128/aem.69.3.1791-1796.2003

  114. 114.

    Sriprang R. Hayashi M. Yamashita M. Ono H. Saeki K. Murooka Y. (2002 ). A novel bioremediation system for heavy metals using the symbiosis between leguminous plant and genetically engineered rhizobia. J. Biotechnol. 99 279–293.

    Not in our library10.1016/s0168-1656(02)00219-5

  115. 115.

    Srivastava S. Chaudhry V. Mishra A. Chauhan P. S. Rehman A. Yadav A. (2012 ). Gene expression profiling through microarray analysis in Arabidopsis thaliana colonized by Pseudomonas putida MTCC5279, a plant growth promoting rhizobacterium. Plant Signal. Behav. 7 235–245.

    Not in our library10.4161/psb.18957

  116. 116.

    Srivastava S. Verma P. C. Chaudhary V. Singh N. Abhilash P. C. Kumar K. V. (2013 ). Inoculation of arsenic-resistant Staphylococcus arlettae on growth and arsenic uptake in Brassica juncea (L.) Czern. Var. R-46. J. Hazard. Mater. 262 1039–1047.

    Not in our library10.1016/j.jhazmat.2012.08.019

  117. 117.

    Steinhorst L. Kudla J. (2014 ). Signaling in cells and organisms-calcium holds the line. Curr. Opin. Plant Biol. 22 14–21.

    Not in our library10.1016/j.pbi.2014.08.003

  118. 118.

    Taj Z. Z. Rajkumar M. (2016 ). “Perspectives of plant growth-promoting actinomycetes in heavy metal phytoremediation,” in Plant Growth Promoting Actinobacteria eds Subramaniam Gopalakrishnan Arumugam Sathya Rajendran (Singapore: Springer) 213–231.

    Not in our library

  119. 119.

    Tangahu B. V. Sheikh Abdullah S. R. Basri H. Idris M. Anuar N. Mukhlisin M. (2011 ). A Review on heavy metals (As, Pb, and Hg) uptake by plants through phytoremediation. Int. J. Chem. Eng. 2011:31

    Not in our library10.1155/2011/939161

  120. 120.

    Thassitou P. Arvanitoyannis I. (2001 ). Bioremediation: a novel approach to food waste management. Trends Food Sci. Technol. 12 185–196.

    Not in our library10.1016/s0924-2244(01)00081-4

  121. 121.

    Thijs S. Langill T. Vangronsveld J. (2017 ). Chapter two-the bacterial and fungal microbiota of hyperaccumulator plants: small organisms, large influence. Adv. Bot. Res. 83 43–86.

    Not in our library10.1016/bs.abr.2016.12.003

  122. 122.

    Tiwari S. Lata C. Chauhan P. S. Nautiyal C. S. (2016 ). Pseudomonas putida attunes morphophysiological, biochemical and molecular responses in Cicer arietinum L. during drought stress and recovery. Plant Physiol. Biochem. 99 108–117.

    Not in our library10.1016/j.plaphy.2015.11.001

  123. 123.

    Tiwari S. Lata C. Singh Chauhan P. Prasad V. Prasad M. (2017a ). A functional genomic perspective on drought signalling and its crosstalk with phytohormone-mediated signalling pathways in plants. Curr. Genomics 18 469–482.

    Not in our library10.2174/1389202918666170605083319

  124. 124.
  125. 125.

    Tiwari S. Singh S. N. Garg S. K. (2012 ). Stimulated phytoextraction of metals from fly ash by microbial interventions. Environ. Technol. 33 2405–2413.

    Not in our library10.1080/09593330.2012.670269

  126. 126.

    Tobin J. M. (2001 ). Fungal metal biosorption. Br. Mycol. Soc. Symp. Ser. 23 424–444.

    Not in our library10.1017/cbo9780511541780.016

  127. 127.

    Traunfeld J. H. Clement D. L. (2001 ). Lead in Garden Soils. Home and Garden, Maryland Cooperative Extention. College Park, MD: University of Maryland.

    Not in our library

  128. 128.

    Tripathi P. Singh P. C. Mishra A. Chaudhry V. Mishra S. Tripathi R. D. (2013 ). Trichoderma inoculation ameliorates arsenic induced phytotoxic changes in gene expression and stem anatomy of chickpea (Cicer arietinum). Ecotoxicol. Environ. Saf. 89 8–14.

    Not in our library10.1016/j.ecoenv.2012.10.017

  129. 129.

    Tripathi P. Singh P. C. Mishra A. Srivastava S. Chauhan R. Awasthi S. (2017 ). Arsenic tolerant Trichoderma sp. reduces arsenic induced stress in chickpea (Cicer arietinum). Environ. Pollut. 223 137–145.

    Not in our library10.1016/j.envpol.2016.12.073

  130. 130.

    Tripathi R. D. Srivastava S. Mishra S. Singh N. Tuli R. Gupta D. K. (2007 ). Arsenic hazards: strategies for tolerance and remediation by plants. Trends Biotechnol. 25 158–165.

    Not in our library10.1016/j.tibtech.2007.02.003

  131. 131.

    Ullah A. Heng S. Munis M. F. H. Fahad S. Yang X. (2015 ). Phytoremediation of heavy metals assisted by plant growth promoting (PGP) bacteria: a review. Environ. Exp. Bot. 117 28–40.

    Not in our library10.1016/j.envexpbot.2015.05.001

  132. 132.

    Uzu G. Sauvain J.-J. Baeza-Squiban A. Riediker M. Hohl M. S. S. Val S. (2011 ). In vitro assessment of the pulmonary toxicity and gastric availability of lead rich particles from a lead recycling plant. Environ. Sci. Technol. 45 7888–7895.

    Not in our library10.1021/es200374c

  133. 133.

    Valls M. Atrian S. de Lorenzo V. Fernández L. A. (2000 ). Engineering a mouse metallothionein on the cell surface of Ralstonia eutropha CH34 for immobilization of heavy metals in soil. Nat. Biotechnol. 18 661–665.

    Not in our library10.1038/76516

  134. 134.

    Verma P. K. Verma S. Pande V. Mallick S. Tripathi R. D. Dhankher O. P. (2016 ). Overexpression of rice glutaredoxin OsGrx_C7 and OsGrx_C2. 1 reduces intracellular arsenic accumulation and increases tolerance in Arabidopsis thaliana. Front. Plant Sci. 7:740.

    Not in our library10.3389/fpls.2016.00740

  135. 135.

    Verma S. Dubey R. S. (2001 ). Effect of Cadmium on soluble sugars and enzymes of their metabolism in rice. Biol. Plant. 44 117–123.

    Not in our library10.1023/a:1017938809311

  136. 136.

    Verma S. Verma P. K. Meher A. K. Bansiwal A. K. Tripathi R. D. Chakrabarty D. (2017 ). A novel fungal arsenic methyltransferase, WaarsM reduces grain arsenic accumulation in the transgenic rice plant. J. Hazard. Mater. 344 626–634.

    Not in our library10.1016/j.jhazmat.2017.10.037

  137. 137.

    Verma S. Verma P. K. Meher A. K. Dwivedi S. Bansiwal A. K. Pande V. (2016 ). A novel arsenic methyltransferase gene of Westerdykella aurantiaca isolated from arsenic contaminated soil: phylogenetic, physiological, and biochemical studies and its role in arsenic bioremediation. Metallomics 8 344–353.

    Not in our library10.1039/c5mt00277j

  138. 138.

    Wagner G. J. (1993 ). Accumulation of cadmium in crop plants and its consequences to human health. Adv. Agron. 51 173–212.

    Not in our library10.1016/s0065-2113(08)60593-3

  139. 139.

    Wang R. Gao F. Guo B. Q. Huang J. C. Wang L. Zhou Y. J. (2013 ). Short-term chromium-stress-induced alterations in the maize leaf proteome. Int. J. Mol. Sci. 14 11125–11144.

    Not in our library10.3390/ijms140611125

  140. 140.

    Wang S. Mulligan C. N. (2006 ). Occurrence of arsenic contamination in Canada: sources, behavior and distribution. Sci. Total Environ. 366 701–721.

    Not in our library10.1016/j.scitotenv.2005.09.005

  141. 141.
  142. 142.

    Wu C. H. Wood T. K. Mulchandani A. Chen W. (2006 ). Engineering plant-microbe symbiosis for rhizoremediation of heavy metals. Appl. Environ. Microbiol. 72 1129–1134.

    Not in our library10.1128/aem.72.2.1129-1134.2006

  143. 143.

    Xiong T. Leveque T. Shahid M. Foucault Y. Mombo S. Dumat C. (2014 ). Lead and cadmium phytoavailability and human bioaccessibility for vegetables exposed to soil or atmospheric pollution by process ultrafine particles. J. Environ. Qual. 43 1593–1600.

    Not in our library10.2134/jeq2013.11.0469

  144. 144.

    Yadav S. K. (2010 ). Heavy metals toxicity in plants: an overview on the role of glutathione and phytochelatins in heavy metal stress tolerance of plants. S. Afr. J. Bot. 76 167–179.

    Not in our library10.1016/j.sajb.2009.10.007

  145. 145.

    Yeh C. M. Hsiao L. J. Huang H. J. (2004 ). Cadmium activates a mitogen-activated protein kinase gene and MBP kinases in rice. Plant Cell Physiol. 45 1306–1312.

    Not in our library10.1093/pcp/pch135

  146. 146.

    Yong X. Chen Y. Liu W. Xu L. Zhou J. Wang S. (2014 ). Enhanced cadmium resistance and accumulation in Pseudomonas putida KT2440 expressing the phytochelatin synthase gene of Schizosaccharomyces pombe. Lett. Appl. Microbiol. 58 255–261.

    Not in our library10.1111/lam.12185

  147. 147.

    Yusuf M. Fariduddin Q. Ahmad A. (2012 ). 24-Epibrassinolide modulates growth, nodulation, antioxidant system, and osmolyte in tolerant and sensitive varieties of Vigna radiata under different levels of nickel: a shotgun approach. Plant Physiol. Biochem. 57 143–153.

    Not in our library10.1016/j.plaphy.2012.05.004

  148. 148.

    Zhang J. Xu J. Pasuquin J. Chen K. Dingkuhn M. Naveed S. A. (2017 ). QTL mapping and candidate gene analysis of ferrous iron and zinc toxicity tolerance at seedling stage in rice by genome-wide association study. BMC Genomics 18:828.

    Not in our library10.1186/s12864-017-4221-5

  149. 149.

    Zhang W. H. Tyerman S. D. (1999 ). Inhibition of water channels by HgCl2 in intact wheat root cells. Plant Physiol. 120 849–858.

    Not in our library10.1104/pp.120.3.849

  150. 150.

    Zhou Z. S. Huang S. Q. Guo K. Mehta S. K. Zhang P. C. Yang Z. M. (2007 ). Metabolic adaptations to mercury-induced oxidative stress in roots of Medicago sativa L. J. Inorg. Biochem. 101 1–9.

    Not in our library10.1016/j.jinorgbio.2006.05.011

  151. 151.

    Zhou Z. S. Wang S. J. Yang Z. M. (2008 ). Biological detection and analysis of mercury toxicity to alfalfa (Medicago sativa) plants. Chemosphere 70 1500–1509.

    Not in our library10.1016/j.chemosphere.2007.08.028

  152. 152.

    Zubair M. Shakir M. Ali Q. Rani N. Fatima N. Farooq S. (2016 ). Rhizobacteria and phytoremediation of heavy metals. Environ. Technol. Rev. 5 112–119.

    Not in our library10.1080/21622515.2016.1259358

Cited by papers we hold 6

Reads

Read by people on this page

None yet.

Checked or read by AI through naulon

None yet.

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.

Are you an author?

Is this your paper?

Claim it to add your note and be paid when agents cite it. Free.