Ni In Shoots Research Articles

Interaction of nickel with oxidative and antioxidative molecules in Cichorioideae species

The uptake of nickel (Ni) by Asteraceae/Cichorioideae species Cichorium intybus, Leontodon hispidus and Hieracium aurantiacum exposed to Ni (0.3 or 30 μM) over 14 days and subsequent changes of metabolites were compared in order to identify their phytoaccumulation potential. Hieracium contained the most Ni (194 and 1558 μg Ni/g DW at 30 μM Ni in shoots and roots) but had unchanged amount of antioxidants (vitamin C and thiols) in the shoots and an elevated amount in the roots, which may be the reason for the absence of visible damage. On the contrary, Leontodon reacted by a decrease in antioxidants to an excess of Ni, which can be related to enhanced oxidative stress (an increase in ROS and a decrease in nitric oxide detected by fluorescence microscopy). All roots were anatomically in the secondary state and Ni-induced cell wall thickening (i.e. lignin/suberin deposition) was most visible in Hieracium roots, which also contained 2-times more Ni than the other species. Among essential elements, mainly Fe accumulation was affected by Ni excess. The content of soluble phenols increased while organic acids (malic and citric) decreased sometimes extensively (up to 90%) in individual species. PCA analyses showed that especially ascorbic acid, thiols and phenols affect the separation in the shoots especially with regard to applied concentration of Ni, while these metabolites in the roots clearly separated the species (Cichorium from the others). The data show the highest tolerance to Ni in Hieracium, but the highest phytoaccumulation of Ni was found in Cichorium (626 μg Ni/plant or 122 μg Ni/shoot at a dose of 30 μM Ni).

Rhizosphere processes by the nickel hyperaccumulator Odontarrhena chalcidica suggest Ni mobilization.

Plant Ni uptake in aboveground biomass exceeding concentrations of 1000μgg-1 in dry weight is defined as Ni hyperaccumulation. Whether hyperaccumulators are capable of mobilizing larger Ni pools than non-accumulators is still debated and rhizosphere processes are still largely unknown. The aim of this study was to investigate rhizosphere processes and possible Ni mobilization by the Ni hyperaccumulator Odontarrhena chalcidica and to test Ni uptake in relation to a soil Ni gradient. The Ni hyperaccumulator O. chalcidica was grown in a pot experiment on six soils showing a pseudo-total Ni and labile (DTPA-extractable) Ni gradient and on an additional soil showing high pseudo-total but low labile Ni. Soil pore water was sampled to monitor changes in soil solution ionome, pH, and dissolved organic carbon (DOC) along the experiment. Results showed that Ni and Fe concentrations, pH as well as DOC concentrations in pore water were significantly increased by O. chalcidica compared to unplanted soils. A positive correlation between Ni in shoots and pseudo-total concentrations and pH in soil was observed, although plant Ni concentrations did not clearly show the same linear pattern with soil available Ni. This study shows a clear root-induced Ni and Fe mobilization in the rhizosphere of O. chalcidica and suggests a rhizosphere mechanism based on soil alkalinization and exudation of organic ligands. Furthermore, it was demonstrated that soil pH and pseudo-total Ni are better predictors of Ni plant uptake in O. chalcidica than labile soil Ni. The online version contains supplementary material available at 10.1007/s11104-023-06161-w.

Alleviation of adverse effects of nickel on growth and concentration of copper and manganese in wheat through foliar application of ascorbic acid

We investigated the role of ascorbic acid (AsA) to alleviate nickel (Ni) induced adverse effects on growth and concentration of Ni, copper (Cu), and manganese (Mn) in hydroponically grown wheat varieties viz. Galaxy, Punjab-2011, and FSD-08. Plants were exposed to five levels of Ni viz. 0, 5, 10, 15, and 20 mg L−1. After 1 week, AsA (1 mM) was sprayed onto the Ni-stressed plants. FSD-08 produced the maximum SDW with and without AsA compared to other varieties. FSD-08, Galaxy, and Punjab-2011 witnessed 2.61-, 2.83-, and 7.5-fold increases in SDW with AsA, respectively. Wheat plants contained the maximum Ni in shoots and roots with a Ni level of 20 mg L−1 irrespective of varieties. Nickel in shoots decreased with AsA witnessing 13, 12, and 10% decrease in FSD-08, Punjab-2011, and Galaxy, respectively. Nickel in roots of FSD-08 decreased by 18% while increased by 3.34-fold and 3.50-fold in Galaxy and Punjab-2011, respectively with AsA. Nickel decreased Cu in shoot and Mn in shoot and root while Cu in roots of all wheat varieties increased. It was concluded that AsA improved the growth of Ni-stressed and FSD-08 performed better by maintaining good growth and less Ni in shoots compared to other varieties.

Phytoremediation of Nickel and Lead Contaminated Soils by Hedera colchica

ABSTRACT Phytoremediation is an effective and affordable technological solution to extract or remove metal pollutants from contaminated soil. In this study, the ability of Hedera colchica plant for the removal of Pb and Ni metals with different concentrations from soil and also metal efficacy on morphological parameters of the plant were investigated. The morphological results showed that as the concentration of heavy metals increases in soil up to 600 mg.kg−1 soil, the dry weights of shoot and root reduce about 46 and 60% with Pb and 18 and 51% with Ni, and also total length up to 31% with Pb and 3% with Ni, respectively. The maximum concentration of Pb and Ni in shoots (92.2 and 77.2 mg.kg−1 Dwt, respectively) and roots (252 and 218 mg.kg−1, respectively) were recorded in the cultivated plant in soil amended with metal high concentrations. The highest bio-concentration (BCF) and translocation factor (TF) were recorded for Pb in the roots. In addition, this study showed that H. colchica plant was more favorable for Pb uptake compared to Ni, but we do not suggest using it for the remediation of the contaminated soils with Pb and Ni metals.

Elevated Expression of Vacuolar Nickel Transporter Gene IREG2 Is Associated With Reduced Root-to-Shoot Nickel Translocation in Noccaea japonica.

A number of metal hyperaccumulator plants, including nickel (Ni) hyperaccumulators, have been identified in the genus Noccaea. The ability to accumulate Ni in shoots varies widely among species and ecotypes in this genus; however, little is known about the molecular mechanisms underlying this intra- and inter-specific variation. Here, in hydroponic culture, we compared Ni accumulation patterns between Noccaea japonica, which originated in Ni-enriched serpentine soils in Mt. Yubari (Hokkaido, Japan), and Noccaea caerulescens ecotype Ganges, which originated in zinc/lead-mine soils in Southern France. Both Noccaea species showed extremely high Ni tolerance compared with that of the non-accumulator Arabidopsis thaliana. But, following treatment with 200 μM Ni, N. caerulescens showed leaf chlorosis, whereas N. japonica did not show any stress symptoms. Shoot Ni concentration was higher in N. caerulescens than in N. japonica; this difference was due to higher efficiency of root-to-shoot Ni translocation in N. caerulescens than N. japonica. It is known that the vacuole Ni transporter IREG2 suppresses Ni translocation from roots to shoots by sequestering Ni in the root vacuoles. The expression level of the IREG2 gene in the roots of N. japonica was 10-fold that in the roots of N. caerulescens. Moreover, the copy number of IREG2 per genome was higher in N. japonica than in N. caerulescens, suggesting that IREG2 expression is elevated by gene multiplication in N. japonica. The heterologous expression of IREG2 of N. japonica and N. caerulescens in yeast and A. thaliana confirmed that both IREG2 genes encode functional vacuole Ni transporters. Taking these results together, we hypothesize that the elevation of IREG2 expression by gene multiplication causes the lower root-to-shoot Ni translocation in N. japonica.

Effects of the exposure of TiO2 nanoparticles on basil (Ocimum basilicum) for two generations

There is a lack of information about the transgenerational effects of titanium dioxide nanoparticles (nano-TiO2) in plants. This study aimed to evaluate the impacts of successive exposure of nano-TiO2 with different surface properties to basil (Ocimum basilicum). Seeds from plants exposed or re-exposed to pristine, hydrophobic, or hydrophilic nano-TiO2 were cultivated for 65 days in soil unamended or amended with 750 mg·kg−1 of the respective particles. Plant growth, concentration of titanium and essential elements, as well as content of carbohydrates and chlorophyll were evaluated. There were no differences on Ti concentration in roots of plants sequentially exposed to pristine or hydrophobic nano-TiO2, or in roots of plants exposed to the corresponding particle, only in the second cycle. However, sequential exposure to hydrophilic particles resulted in 65.2% less Ti in roots, compared to roots of plants exposed the same particles, only in the second cycle. The Ti concentrations in shoots were similar in all treatments. On the other hand, pristine and hydrophilic particles reduced Mg in root by 115% and 81%, respectively, while pristine and hydrophobic particles reduced Ni in shoot by 84% and 75%, respectively, compared to unexposed plants in both cycles. Sequential exposure to pristine nano-TiO2 increased stomatal conductance (214%, p ≤ 0.10), compared to plants that were never exposed. Hydrophobic and hydrophilic nano-TiO2 reduced chlorophyll b (52%) and total chlorophyll (30%) but increased total sugar (186%) and reducing sugar (145%), compared to unexposed plants in both cycles. Sequential exposure to hydrophobic or hydrophilic nano-TiO2 resulted in more adverse effects on photosynthesis but in positive effects on plant growth, compared to pristine nano-TiO2.

Improvement in productivity, nutritional quality, and antioxidative defense mechanisms of sunflower (Helianthus annuus L.) and maize (Zea mays L.) in nickel contaminated soil amended with different biochar and zeolite ratios

Nickel (Ni) contaminated soils pose a potential ecological risk to the environment, soil health, and quality of food produced on them. We hypothesized that application of miscanthus biochar (BC) and cationic zeolite (ZE) at various proportions into a Ni contaminated soil can efficiently immobilize Ni and reduce its bioavailability to sunflower (Helianthus annuus L.) and maize (Zea mays L.). An electroplating effluent contaminated soil was amended with BC and ZE, as sole treatments (2% w/w) and their combinations of various ratios (BC, ZE, BC25%ZE75%, BC50%ZE50% and BC75%ZE25%) for immobilization of Ni in the soil. Furthermore, the associated effects of these treatments on residual and DTPA-extractable Ni from the soil; concentrations of Ni in shoots, roots, and grain; growth, physiology, biochemistry and the antioxidant defence mechanisms of sunflower and maize were investigated. Results revealed that BC50%ZE50% treatment efficiently reduced DTPA-extractable Ni in the soil, Ni concentrations in shoots, roots, and grain, while improved selective parameters of both plants. Interestingly, the BC75%ZE25% treatment significantly improved the biomass, grain yield, physiology, biochemistry and antioxidant defense machinery, while decreased Ni oxidative stress in both sunflower and maize, compared to rest of the treatments. The results demonstrate that the BC50%ZE50% treatment can efficiently reduce Ni concentrations in the roots, shoots and grain of both sunflower and maize whereas, an improvement in biomass, grain yield, physiological, biochemical, and antioxidant defense machinery of both crops can only be achieved with the application of BC75%ZE25% treatment in a Ni contaminated soil.

Judicious use of kinetin to improve growth and yield of rice in nickel contaminated soil

ABSTRACTThe present study was conducted to evaluate the effect of kinetin on growth and yield of rice in the presence and absence of nickel contamination. Rice seedlings were dipped in kinetin solution (10−3, 10−4 and 10 M−5) for 2 hours and transplanted in pots having soil contaminated with nickel sulfate @ 130 mg kg−1. Experiment was laid out according to completely randomized design with four replications. Results revealed that kinetin significantly improved growth and yield of rice grown in nickel contamination. Kinetin @ 10−4 M showed maximum improvement in plant height, paddy yield, 1000 grain weight, number of tillers and panicles up to 9.76, 15.72, 11.77, 11.87, and 10.90%, respectively, as compared to plants grown in contaminated soil without kinetin. Kinetin also improved the uptake of nutrients (NPK) in straw and grain of plants grown in Ni contaminated soil. Plants treated with kinetin had more concentration of Ni in shoot but less in grain compared to plants grown in Ni contaminated soil without application of kinetin. The application of kinetin can reduce stress effect on plants through improvement in the biomass of plant. This strategy could be used to increase the phytoextraction of Ni from the contaminated soil.

Effect of Nickel and Vermicompost on Growth, Yield, Accumulation of Heavy Metals and Essential Oil Quality of Tagetes minuta

The effect of nickel and vermicompost on growth yield and chemical composition of essential oil and mineral element accumulation of Tagetes minuta was studied in a pot experiment. The shoot yield of Tagetes minuta was significantly increased by the application of vermicompost and nickel up to 30 ppm as compared to control. The maximum increase in shoot yield was 48 % over control by the application of 10 ppm Ni with vermicompost. The plant height and number of branches per plant were significantly increased by the application of 10 ppm of Ni alone and in combination with vermicompost as compared to control and further increase in the level of Ni decrease the plant height and number of branches per plant. The level of dihydrotagetone and ocimene in Tagetes minuta oil were significantly decreased by the application of higher level of Ni (50 ppm) compared to control. The level of tagetone in T. minuta oil was decreased by the application of Ni alone and in combination with vermicompost as compared to control. The concentration of Ni in shoot and root tissues was significantly enhanced by the application of Ni and vermicompost. The concentration of Ni in leaf tissues of T. minuta was significantly higher than in the stem and root tissues. These results suggests that growing of T. minuta with vermicompost could be used as a green technology for rehabilitation and phytoremediation of Ni-contaminated soils.

Heavy Metals Affect Yield, Essential Oil Compound, and Rhizosphere Microflora of Vetiver (Vetiveria zizanioides Linn. nash) Grass

The effects of heavy metals [chromoium (Cr), cadmium (Cd), lead (Pb) and nickel (Ni)] on the yield, khusimol content in the essential oil, accumulation of metals, and rhizosphere microflora of vetiver (Vetiveria zizanoides) were studied in a pot experiment. The shoot yield and khusimol content in oil of vetiver were enhanced by the application of moderate amount of metals to soils. The application of Cr, Pb, and Ni had deleterious effects on the root and essential oil yield. The application of high levels of metals to soil had harmful effects on the bacterial and fungal counts in the rhizosphere. The concentrations of metals such as Cr, Cd, Pb, and Ni in shoot and root tissues were significantly enhanced by the application of those metals to soils. It can be concluded that the vetiver could be used as a promising crop for revegetation, soil remediation, and production of better quality essential oil in metal-contaminated soils.

Contrasting Effects of Farmyard Manure (FYM) and Compost for Remediation of Metal Contaminated Soil

We investigated effect of farm yard manure (FYM) and compost applied to metal contaminated soil at rate of 1% (FYM-1, compost-1), 2% (FYM-2, compost-2), and 3% (FYM-3, compost-3). FYM significantly (P < 0.001) increased dry weights of shoots and roots while compost increased root dry weight compared to control. Amendments significantly increased nickel (Ni) in shoots and roots of maize except compost applied at 1%. FYM-3 and -1 caused maximum Ni in shoots (11.42 mg kg−1) and roots (80.92 mg kg−1), respectively while compost-2 caused maximum Ni (14.08 mg kg−1) and (163.87 mg kg−1) in shoots and roots, respectively. Plants grown in pots amended with FYM-2 and compost-1 contained minimum Cu (30.12 and 30.11 mg kg−1) in shoots, respectively. FYM-2 and compost-2 caused minimum zinc (Zn) (59.08 and 66.0 mg kg−1) in maize shoots, respectively. FYM-2 caused minimum Mn in maize shoots while compost increased Mn in shoots and roots compared to control. FYM and compost increased the ammonium bicarbonate diethylene triamine penta acetic acid (AB-DTPA) extractable Ni and Mn in the soil and decreased Cu and Zn. Lower remediation factors for all metals with compost indicated that compost was effective to stabilize the metals in soil compared to FYM.

High Ni Levels in Soil Can Modify Growth Performance and Mineral Status of Wheat Cultivars

Nickel (Ni) contamination in soil is a widespread problem in this era of industrial development. Plant cultivars respond differentially to Ni contamination in soil. In the present study, we have investigated the effect of different Ni levels to the growth and mineral status of two wheat cultivars (Sehar‐2006 and LU‐26). Five different levels of Ni as NiSO4 · 4 H2O (0, 30, 45, 60, and 75 mg kg−1) were applied to soil in the pots. LU‐26 performed better compared to Sehar‐2006 in terms of dry weight production and physiological parameters. LU‐26 contained higher Ni in roots compared to Sehar‐2006, but the Ni concentration in shoots of both the cultivars was similar. LU‐26 translocated less Ni toward the shoot compared to Sehar‐2006 indicating the exclusion of Ni from shoots and retaining it in roots by LU‐26 as evident from bioconcentration and translocation factors. Contradictly, Sehar‐2006 translocated more Ni from root to shoot indicating its tolerance to Ni. Ni increased manganese (Mn) in shoots of Sehar‐2006 and LU‐26 up to 60 and 30 mg kg−1, respectively. Ni decreased copper (Cu) and zinc (Zn) concentration in shoots of both cultivars, however Zn concentration in roots increased at all levels of Ni. LU‐26 excluded Ni from shoots and Sehar‐2006 accumulated Ni in shoots. The present study helps in understanding the process of metal uptake and distribution during the early growth stages of the plant and can signify overall potential of a crop for its exploitation on contaminated soils.

Molecular cloning and characterization of a Brassica juncea yellow stripe-like gene, BjYSL7, whose overexpression increases heavy metal tolerance of tobacco

BjYSL7 encodes a plasma-localized metal-NA transporter and has transport Fe(II)-NA complexes activity. BjYSL7 is involved in the transport of Cd and Ni from roots to shoots. Heavy metal transporters play a key role in regulating metal accumulation and transport in plants. In this study, we isolated a novel member of the yellow stripe-like (YSL) gene family BjYSL7 from the hyperaccumulator Brassica juncea. BjYSL7 is composed of 688 amino acids with 12 putative transmembrane domains and is over 90 % identical to TcYSL7 and AtYSL7. Real-time PCR analysis revealed that BjYSL7 mRNA was mainly expressed in the stem under normal condition. The expression of BjYSL7 was found to be up-regulated by 127.1-, 12.7-, and 3.4-fold in roots and 6.5-, 4.3-, and 2.8-fold in shoots under FeSO4, NiCl2, and CdCl2 stresses, respectively. We have demonstrated that BjYSL7 is a Fe(II)-NA influx transporter by yeast functional complementation. Moreover, a BjYSL7::enhanced green fluorescent protein (EGFP) fusion localized to the plasma membrane of onion epidermal cells. The BjYSL7-overexpressing transgenic tobacco plants exhibited longer root lengths, lower relative inhibition rate of lengths and superior root hair development compared to that of wild-type (WT) plants in the presence of CdCl2 and NiCl2. Furthermore, the concentrations of Cd and Ni in shoots of BjYSL7-overexpressing plants are significantly higher than that of WT plants. Compared with WT plants, BjYSL7-overexpressing plants exhibited Fe concentrations that were higher in the shoots and seeds and lower in the roots. Taken together, these results suggest that BjYSL7 might be involved in the transport of Fe, Cd and Ni to the shoot and improving heavy metal resistance in plants.

Effects of Nickel Hyperaccumulation on Physiological Characteristics of Alyssum Murale Grown on Metal Contaminated Waste Amended Soil

A pot experiment was conducted to investigate the effect of nickel concentration on physiological characteristics of Alyssum murale when grown in a soil mixed with sewage sludge (at the rate of 2.8%). Two types of sludge were used: agricultural sewage sludge (S1) and industrial sewage sludge with an increasing nickel concentration (S2, S3, and S4). Results showed that Ni in shoots was higher than Ni in roots. A. murale is able to concentrate up to 12730 mg/kg Ni in leaves. The highest dry matter yield was observed with plants grown with agricultural sewage sludge. An addition of S2 and S3 increased shoot biomass. However, application of S4 reduced 40% shoot dry weight as compared to the control. Ni treatment did not affect all chlorophyll fluorescence parameters. The Fv/Fm ratio was stable between Ni treatments. Photosynthesis rate (A) increased with agricultural sewage sludge, but remained stable with variable Ni rates from the industrial sludge. The chlorophyll content increased with S1, S2 and S3 but it remains constant with S4 when compared to the control. Therefore, high nickel concentration did not affect the function of the photosynthetic machine of A. murale.

Interactive effects of lead, copper, nickel and zinc on growth, metal uptake and antioxidative metabolism of Sesbania drummondii

Sesbania drummondii seedlings were grown in a medium to which lead (Pb), copper (Cu), nickel (Ni) and zinc (Zn) were added singly and in combinations in order to assess the effects of metal interactions on seedling growth, metal accumulation and anti-oxidative system. S. drummondii growth was significantly inhibited with metal treatments. S. drummondii accumulated substantially higher concentrations of metals in the roots than shoots. The uptake of metals followed the order Pb>Cu>Zn>Ni in roots and Pb>Zn>Cu>Ni in shoots. In addition, uptake of a single metal by S. drummondii was affected by the presence of a second metal, suggesting an antagonistic effect or competition between metals at the plant uptake site. A significant increase in both enzymatic [superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR)] and non-enzymatic (glutathione) antioxidant was observed in the S. drummondii seedlings exposed to different metal treatments. The enhancement in enzyme activities followed the order of Cu>Ni>Pb>Zn. However, compared to the effect of individual metal, metals in combination increased the enzyme activities to varying degrees.

The Accumulation of Zinc and Nickel in Irankoh Indigenous Plant Species on a Contaminated Land

The accumulation of heavy metals by plants determines both the micronutrient content and the toxic metal content of our food. A field survey of higher terrestrial plants growing on a metalliferous site of the Iranian arid mountain in Isfahan was conducted to identify species accumulating exceptionally large concentrations of Zn and Ni in shoots and roots. Plant samples were collected from Irankoh areas near the Bama Pb and Zn mine. Sampling was carried out in Spring 2004 and analyzed for DTPA (Diethylene triamine pentaacetic acid) extractable Zn and Ni by atomic absorption spectrophotometry. Mean total and available Zn in the studied soils were 259.7 μgg−1 and 5.067 μgg−1, respectively. Soil total and available Ni were relatively low (58.9 μgg−1 and 0.143 μgg−1 respectively). Zinc concentrations were considerably high in shoots of Stachys inflate, Ebenus stellata, and Astragalus glaucanthus (556.88, 508.8, and 449.53 μgg−1, respectively). Nickel concentrations were markedly high in shoots of Teucrium polium, Alyssum bracteatum, and Ebenus stellata (13.21, 10.98, and 8.84 μgg−1, respectively). Zinc translocation factor (TF or shoot/root concentration ratio) was higher than Ni TF in most plant species. Zinc and Ni enrichment factors and shoot/root concentration ratios were also significantly high in Stachys inflate, Ebenus stellata, Astragalus glaucanthus Teucrium polium, Stipa barbata, Bromus tectorum, and Alyssum bracteatum. Results suggest that these plants could be good candidates for use in the revegetation and phytoremediation of Zn and Ni contaminated lands in arid regions.

In Situ Remediation of Nickel Phytotoxicity for Different Plant Species#

Acidic nickel (Ni)-contaminated soils in the vicinity of a Ni refinery at Port Colborne (Ontario, Canada) cause Ni phytotoxicity and require remediation. Thus, a greenhouse test with 11 plant species with a wide range of susceptibility to Ni toxicity was conducted to determine if Ni phytotoxicity of all species could be ameliorated by a high rate of limestone. At the original pH of 5.2, the Welland soil (Typic Epiaquoll; 2900 mg kg−1 Ni) was severely phytotoxic to all plant species tested. Toxicity symptoms in dicots included interveinal chlorosis and necrosis of leaves. In grasses, a banded chlorosis was present. Two limestone rates, 2.5 and 50 Mg ha−1, were included in the test. Both liming and plant species significantly affected soil pH, and 0.01 M Sr(NO3)2-extractable soil Ni. Increase in pH exponentially decreased Sr(NO3)2-extractable soil Ni. Grass species were more resistant to Ni toxicity than dicots. Liming soil to pH of 5.9–6.3 enabled good growth of several grass species, but dicot species were still stunted or died. Making the soil calcareous (pH 7.7–7.8) ameliorated Ni toxicity of this highly contaminated soil for all species tested. Concentration of Ni in shoots associated with 25% yield reduction varied among species ranging from 9 to 122 mg kg−1 dry shoots. #Use of names of products by the U.S. Department of Agriculture neither guarantees or warrants the standard of the product, nor implies approval of the product to the exclusion of others that may also be suitable.

Remediating Ni-phytotoxicity of contaminated Quarry muck soil using limestone and hydrous iron oxide

Remediation of excessive soil metals in situ is receiving new attention because the alternative, soil removal and replacement, is very expensive, requires disposal of the removed soil and may achieve no better environmental remediation than the in situ treatments. A factorial pot experiment was conducted with two muck soils contaminated by a Ni refinery; we tested the effectiveness of making the soil calcareous and addition of freshly precipitated hydous ferric oxide (HFO) in reducing soil Ni phytotoxicity to the Ni-sensitive crops, oat and redbeet, and a Ni-resistant crop, wheat. Fertilized but otherwise untreated soil caused significant Ni phytotoxicity to oats and redbeet, but not to wheat, on both soils. Adding limestone reduced the concentration of Ni in shoots of all species and alleviated the symptoms specific to Ni phytotoxicity in oat (banded chlorosis). The addition of HFO was more effective in reducing shoot Ni concentration in the redbeets than in crops from the Poaceae family. Both amendments induced phosphorus and/or manganese deficiency depending on the crop tested. The experiment indicates that some combination of limestone and Fe oxides can readily remediate Ni phytotoxicity of the tested soils, but that Mn and P fertilizers would be needed to achieve practical in situ remediation of Ni phytotoxicity of Quarry muck (Terric Mesisol). Key words: Nickel, soil, plant, phytotoxicity, remediation