Intraspecific differences of arbuscular mycorrhizal fungi in their impacts on arsenic accumulation by Pteris vittata L

Inoculation with Funneliformis mosseae promotes selenium accumulation and transformation in pepper (Capsicum annuum L.)

Selenium (Se) is one of the fifteen essential nutrients required by the human body. Mycorrhizal microorganisms play a crucial role in enhancing selenium availability in plants. However, limited research exists on the impact of arbuscular mycorrhizal fungi (AMF) on selenium accumulation and transport in pepper plants. This study employed a pot experiment to investigate the changes in pepper plant growth, selenium accumulation, and transformation following inoculation with AMF and varying concentrations of exogenous selenium. The results indicate that exogenous selenium application in pepper has dual effects. At low concentrations (≤8 mg L⁻1), it promotes growth and nutrient accumulation, whereas high concentrations (>16 mg L⁻1) inhibit these processes. AMF inoculation positively influences selenium accumulation and transport in peppers, significantly increasing yield per plant by 17.89%, vitamin C content by 67.36%, flavonoid content by 43.26%, capsaicin content by 14.82%, DPPH radical scavenging rate by 18.18%, and ABTS radical scavenging rate by 27.81%. Additionally, it significantly reduces selenocysteine methyltransferase (SMT) enzyme activity, while minimally affecting ATP sulfurylase (ATPS) and adenosyl sulfate reductase (APR) enzyme activities. The combined treatment of AMF and 8 mg L⁻1 exogenous selenium has been proven to be the most effective for selenium enrichment in peppers, offering new insights into utilizing exogenous selenium and AMF inoculation to enhance selenium content in peppers.

The function and community structure of arbuscular mycorrhizal fungi in ecological floating beds used for remediation of Pb contaminated wastewater

Arbuscular mycorrhizal fungi (AMF) have been demonstrated to be ubiquitous in aquatic ecosystems. However, their distributions and ecological functions are rarely studied. To date, a few studies have combined sewage treatment facilities with AMF to improve removal efficiency, but appropriate and highly tolerant AMF strains have not been explored, and the purification mechanisms remain unclear. In this study, three ecological floating-bed (EFB) installations inoculated with different AMF inocula (mine AMF inoculum, commercial AMF inoculum and non-AMF inoculated) were constructed to investigate their removal efficiency for Pb-contaminated wastewater. The AMF community structure shifts in the roots of Canna indica inhabiting EFBs during the three phases (pot culture phase, hydroponic phase and hydroponic phase with Pb stress) were tracked utilizing quantitative real-time polymerase chain reaction and Illumina sequencing techniques. Furthermore, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) were used to detect the Pb location in mycorrhizal structures. The results showed that AMF could promote host plant growth and enhance the Pb removal efficiency of the EFBs. The higher the AMF abundance, the better the effect of the AMF on Pb purification by EFBs. Both flooding and Pb stress decreased the AMF diversity but did not significantly inhibit the abundance. The three inoculation treatments showed different community compositions with different dominant AMF taxa in different phases, and an uncultured Paraglomus species (Paraglomus sp. LC516188.1) was found to be the most dominant (99.65 %) AMF in the hydroponic phase with Pb stress. The TEM and EDS analysis results showed that the Paraglomus sp. could accumulate Pb in plant roots through their fungal structures (intercellular mycelium, intracellular mycelium, etc.), which alleviated the toxic effect of Pb on plant cells and limited Pb translocation. The new findings provide a theoretical basis for the application of AMF in plant-based bioremediation of wastewater and polluted waterbodies.

Effects of arbuscular mycorrhizal fungi on accumulation and translocation of selenium in winter wheat

BACKGROUND

Selenium (Se) is an essential micronutrient for humans and animals, but not for plants. Generally, cereals including wheat and rice are the main source of dietary Se for humans. Although arbuscular mycorrhizal fungi (AMF) are ubiquitous soil microbes and commonly develop symbionts with winter wheat (Triticum aestivum L.), the influence of AMF on accumulation and translocation of Se during developmental cycle of winter wheat is still unclear.

RESULTS

Based on a pot trial, the present results indicated that the effects of AMF on grain Se concentration in winter wheat depend on the Se species spiked in the soil and that Rhizophagus intraradices (Ri) significantly enhanced grain Se concentration under selenite treatment. Moreover, inoculation of AMF significantly increased grain Se content under selenite and selenate treatments. The enhanced grain Se content of mycorrhizal wheat could be attributed to (i) apparently increased root growth of mycorrhizal wheat at jointing could absorb more Se for translocating to aerial tissues and consequently result in significantly higher stalk Se content and (ii) enhancing Se translocation from vegetative tissues to grains. The present study showed that AMF significantly (P < 0.05) increased pre-anthesis Se uptake under selenate treatment and post-anthesis Se uptake under selenite treatment.

CONCLUSION

The present study indicated the feasibility of inoculation of AMF for increasing grain Se concentration under selenite treatment and enhancing the efficiency of biofortification of Se under selenate treatments. © 2022 Society of Chemical Industry.

Selenium uptake and accumulation in winter wheat as affected by level of phosphate application and arbuscular mycorrhizal fungi

Selenium (Se) is an advantageous element to crops. However, the influence of arbuscular mycorrhizal fungi (AMF), phosphate (P) and selenite in soil on Se uptake by winter wheat remain elusive. Pot trials were carried out including seven levels of P (0, 12.5, 25, 50, 100, 200 or 400 mg kg^-1) and non-mycorrhizal inoculation (NM), inoculation of Funneliformis mosseae (F.m) or Glomus versiforme (G.v). The present results found that grain phosphorus concentration increased with increase of P level from 0 to 100 mg kg^-1 and then tended to plateau, while grain Se concentration decreased with the level of P from 0 to 400 mg kg^-1. Based on mathematical modeling, inoculation of F.m or G.v dramatically improved grain Se concentration by 16.90% or 12.53% under the lower level of P (48.76 mg kg^-1). Furthermore, partial least squares path modeling (PLS-PM) identified that both up-regulated of the expression of AMF-inducible phosphate transporter and improved Se bioavailability in rhizosphere soil contributed to enhancing plant Se concentration under P levels ≤ 100 mg kg^-1. The present study demonstrated that AMF combined with 48.76 mg kg^-1 P applied in soil can not only achieve high grain yield, but also fully exploit the biological potential of Se uptake in wheat.

Influence of arbuscular mycorrhizal fungi on selenium uptake by winter wheat depends on the level of selenate spiked in soil

Selenium (Se) deficiency has been a public health concern for years. Arbuscular mycorrhizal fungi (AMF) play an essential role in improving Se uptake in crops, but related mechanisms still remain unclear. To explore the influence of AMF on uptake of Se in winter wheat, a pot experiment was conducted to inoculate wheat with Funneliformis mosseae (F.m) or not under different levels of selenate in soil. The present results indicated that inoculation of F.m significantly (p < 0.05) increased Se concentration in shoots and roots of wheat under low level of selenate (≤5.0 mg kg^-1) treatments, while the contrary pattern was recorded under high level of selenate (15 and 20 mg kg^-1) treatments. Moreover, inoculation of F.m significantly increased concentration of available Se in soil by 4.68-34.05%. Under selenate ≤5 mg kg^-1 treatments, the expression of TaeSultr1;1 and TaeSultr1;3 in roots of mycorrhizal wheat was significantly up-regulated by 3.06-5.53 and 0.63-5.12 times, while reached saturation under selenate >5 mg kg^-1 treatments. In addition, partial least squares path modeling (PLS-PM) showed that inoculation of AMF directly affected the expression of sulfate transporter and that both sulfate transporter and soil Se fractions played a significant positive effect on plant Se content. The present study indicated that AMF on Se concentration in winter wheat depends on the level of selenate spiked in soil and added to our understanding of the functions and applications of AMF on crop Se absorption.

Arbuscular Mycorrhizal Fungi Are an Influential Factor in Improving the Phytoremediation of Arsenic, Cadmium, Lead, and Chromium

The increasing expansion of mines, factories, and agricultural lands has caused many changes and pollution in soils and water of several parts of the world. In recent years, metal(loid)s are one of the most dangerous environmental pollutants, which directly and indirectly enters the food cycle of humans and animals, resulting in irreparable damage to their health and even causing their death. One of the most important missions of ecologists and environmental scientists is to find suitable solutions to reduce metal(loid)s pollution and prevent their spread and penetration in soil and groundwater. In recent years, phytoremediation was considered a cheap and effective solution to reducing metal(loid)s pollution in soil and water. Additionally, the effect of soil microorganisms on increasing phytoremediation was given special attention; therefore, this study attempted to investigate the role of arbuscular mycorrhizal fungus in the phytoremediation system and in reducing contamination by some metal(loid)s in order to put a straightforward path in front of other researchers.

AM fungi increase uptake of Cd and BDE-209 and activities of dismutase and catalase in amaranth (Amaranthus hypochondriacus L.) in two contaminants spiked soil

Soil co-contaminated with cadmium (Cd) and decabromodiphenyl ether (BDE-209) is a widespread environmental problem, especially in electronic waste contaminated surroundings. Accumulation of Cd and BDE-209 in crops has possibly harmful effects on local human health. In order to assess the potential of arbuscular mycorrhizal (AM) fungi and amaranth (Amaranthus hypochondriacus L.) in remediation of soil co-contaminated with Cd and BDE-209, pot trials were performed to investigate interactive effects of AM fungi, Cd and BDE-209 on growth of amaranth, uptake of Cd and BDE-209, distribution of chemical forms of Cd and activities of antioxidant enzymes in shoots and dissipation of BDE-209 in soil. The present results showed that shoot biomass of non-mycorrhizal plants was significantly inhibited by increasing of Cd addition (5-15 mg kg^-1), but were only slightly declined with BDE-209 addition (5 mg kg^-1). The interaction of Cd and BDE-209 reduced the proportions of ethanol- and d-H₂O-extractable Cd in shoots, consequently alleviated Cd toxicity to plants and enhanced root uptake of Cd and BDE-209. Inoculation of AM fungi resulted in significantly greater shoot biomass as well as higher concentrations of Cd and BDE-209 compared with non-mycorrhizal treatment. Moreover, AM fungi played a beneficial role in relieving oxidative stress on amaranth by increasing the activities of dismutase (SOD) and catalase (CAT) in shoots and significantly improved the dissipation of BDE-209 in soil. The present study suggested that combination of AM fungi and amaranth may be a potential option for remediation of Cd and BDE-209 co-contaminated soils.

Response of growth, antioxidant enzymes and root exudates production towards As stress in Pteris vittata and in Astragalus sinicus colonized by arbuscular mycorrhizal fungi

The modern agricultural practices have led to improve the contaminated soils with a variety of heavy metals that have become a major environmental concern. The use of arbuscular mycorrihizal fungi (AMF) is considered a potential tool for the sustainable agriculture especially in contaminated sites. Moreover, recently, the use of AMF has become a fascinating and multidisciplinary subject for the scientists dealing with plant protection. The present study was carried out to evaluate the interaction among arsenic (As) species, AMF, and two plant species: Pteris vittata and Astragalus sinicus, differing in their metal tolerance. Results about A. sinicus revealed that the biomass was affected as As (III and V) accumulated in the roots of A. sinicus, and in rachis and pinnae of P. vittata. The inoculation of AMF markedly increased the biomass yield of the both plants when exposed to As species. The exposure to the As species resulted variation and non-significant results about antioxidant enzymes and non-enzymes when grown in As stress with and without AMF. The inoculation of AMF under As species improved the organic acids concentrations in both plant species. Overall, the concentration of oxalate acid was more than formic and malic acids; however, AMF inoculation improved more organic acids in A. sinicus. P. vittata exhibited more activities of antioxidant enzymes and non-enzymes under As stress with and without AMF than A. sinicus, and hence had a more efficient defense mechanism.

Influence of arbuscular mycorrhizal fungi on antimony phyto-uptake and compartmentation in vegetables cultivated in urban gardens

1.

CONTEXT

Urban areas are often contaminated with various forms of persistent metal (loid) and emerging contaminants such as antimony (Sb). Thus, in the context of urban agriculture where sustainable practices such as biofertilizers application (arbuscular mycorrhizal fungi, AMF) could improve nutrient transfer from the soil to the vegetables, the effect of AMF on metal (loid) mobility and human bioaccessibility is still poorly known. 2.

METHODS

The role of AMF in Sb uptake by lettuce and carrot grown in artificial substrate spiked with different Sb chemical species was investigated. Plants were grown under hydroponic conditions and half of the treatments received a concentrated spore solution to obtain mycorrhized and non-mycorrhized plants. Three weeks before harvest, plants were exposed to 10 mg.L^-1 of either Sb₂O₃ or KSbO-tartrate (KSb). 3.

RESULTS

The presence of AMF significantly increased its accumulation in carrots (all organs) with higher accumulation in roots. In lettuce, accumulation appeared to be dependent on the Sb chemical species. Moreover, it was observed for the first time that AMF changed the human bioaccessible fraction of Sb in edible organs. 4.

IMPLICATIONS

The present results highlight a possible risk of Sb transfer from soil to edible plants cultivated in soil naturally containing AMF propagules, or when AMF are added as biofertilizers. After validating the influence of soil environment and AMF on Sb behavior in the field, these results should be considered in health risk assessments.

Nitrogen fertilizer enhances growth and nutrient uptake of Medicago sativa inoculated with Glomus tortuosum grown in Cd-contaminated acidic soil

This study aimed to explore whether nitrogen availability could influence mycorrhizal function and their associations with host plants in Cd-contaminated acidic soils or not. A greenhouse pot experiment was conducted to assess the effects of mycorrhizal inoculation (non-mycorrhizal inoculation (NM), Glomus aggregatum (Ga), G. tortuosum (Gt) and G. versiforme (Gv)) and inorganic N amendment on the growth, nutrient and Cd uptake of Medicago sativa grown in Cd-contaminated acidic soils (10 mg Cd kg^-1 soil). AMF inoculations significantly increased the shoot and total biomass and decreased the shoot Cd concentration in comparison to plants uninoculated. N addition increased markedly concentration and content of N and decreased those of P in plants at all inoculation treatments. Shoot K, Na and Mg concentration in plants inoculated with Ga and Gv were decreased by N addition, whereas shoot K, Na, Ca and Mg concentration in plants inoculated with Gt were not negatively affected. It was observed that N addition only increased mycorrhizal colonization, shoot biomass, shoot K, Ca and Mg content of plants inoculated with Gt. Irrespective of N addition, plants with Gt inoculation got the maximum shoot and root P concentration and content, as well as P/Cd concentration molar ratio among all inoculation treatment. Neither AMF nor N fertilizer contributed to the decrease of soil exchangeable Cd and increase of soil pH. These results suggested that N fertilizer only elevated plant performance of alfalfa with Gt inoculation grown in acidic soil, by diluting Cd concentration and alleviating of nutrient deficiency, especially P.

Arbuscular mycorrhizal fungi reduced the ratios of inorganic/organic arsenic in rice grains

Arbuscular mycorrhizal fungi (AMF) - Rhizophagus intraradices was inoculated to rice to investigate its effects on arsenic (As) uptake, grain As speciation, and rhizospheric As concentration of six rice cultivars grown in As-amended soil (60 mg As kg(-1) soil). The AMF inoculation induced either positive, neutral or negative responses in rice grown in As contaminated soil, suggesting that functional diversity may exist in AMF symbiosis when As is taken up and transferred. The ratios of inorganic/organic As concentrations in rice grains of all cultivars were significantly reduced by AMF, that involved the transformation of inorganic As into less toxic organic form dimethylarsinic acid (DMA) in rice. AMF decreased significantly total As and inorganic As concentrations in rice grains of Handao 3. Positive correlations (R(2) = 0.30-0.56, P < 0.05) between As in the rhizospheric soil solution and As in rice grain at different periods were observed. This inferred that the As survey of soil solution can be an effective measure for evaluating As in grains.

Grain yield and arsenic uptake of upland rice inoculated with arbuscular mycorrhizal fungi in As-spiked soils

A pot trial was conducted to investigate the effects of three arbuscular mycorrhizal (AM) fungi species, including Glomus geosporum BGC HUN02C, G. versiforme BGC GD01B, and G. mosseae BGC GD01A, on grain yield and arsenic (As) uptake of upland rice (Zhonghan 221) in As-spiked soils. Moderate levels of AM colonization (24.1-63.1 %) were recorded in the roots of upland rice, and up to 70 mg kg(-1) As in soils did not seem to inhibit mycorrhizal colonization. Positive mycorrhizal growth effects in grain, husk, straw, and root of the upland rice, especially under high level (70 mg kg(-1)) of As in soils, were apparent. Although the effects varied among species of AM fungi, inoculation of AM fungi apparently enhanced grain yield of upland rice without increasing grain As concentrations in As-spiked soils, indicating that AM fungi could alleviate adverse effects on the upland rice caused by As in soils. The present results also show that mycorrhizal inoculation significantly (p < 0.05) decreased As concentrations in husk, straw, and root in soils added with 70 mg kg(-1) As. The present results suggest that AM fungi are able to mitigate the adverse effects with enhancing rice production when growing in As-contaminated soils.

Molecular diversity of arbuscular mycorrhizal fungi at a large-scale antimony mining area in southern China

Arbuscular mycorrhizal fungi (AMF) have great potential for assisting heavy metal hyperaccumulators in the remediation of contaminated soils. However, little information is available about the community composition of AMF under natural conditions in soils contaminated by antimony (Sb). The objective of this study was to investigate the characteristics of AMF molecular diversity, and to explore the effects of Sb content and soil properties on the AMF community structure in an Sb mining area. Four Sb mine spoils and one adjacent reference area were selected from around the Xikuangshan mine in southern China. The association of AMF molecular diversity and community composition with the rhizosphere soils of the dominant plant species was studied by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE). Results from all five studied sites showed that the diversity of AMF decreased with increasing Sb concentration. Principal component analysis (PCA) indicated that the AMF community structure was markedly different among these groups. Further redundancy analysis (RDA) showed that Sb contamination was the dominating factor influencing the AMF community structure in the Sb mine area. However, the multivariate analysis showed that, apart from the soil Sb content, extractable nitrogen content and organic matter content also attributed to AMF sequence distribution type. Some AMF sequences were only found in the highly contaminated area and these might be ideal candidates for improving phytoremediation efficiency in Sb mining regions. Gene sequencing analysis revealed that most species were affiliated with Glomus, suggesting that Glomus was the dominant AMF genus in the studied Sb mining area.

Integrated phytobial remediation for sustainable management of arsenic in soil and water

Arsenic (As), cited as the most hazardous substance by the U.S. Agency for Toxic Substance and Disease Registry (ATSDR, 2005), is an ubiquitous metalloid which when ingested for prolonged periods cause extensive health effects leading to ultimate untimely death. Plants and microbes can help mitigate soil and groundwater As problem since they have evolved elaborate detoxification machineries against this toxic metalloid as a result of their coexistence with this since the origin of life on earth. Utilization of the phytoremediation and bioremediation potential of the plants and microbes, respectively, is now regarded as two innovative tools that encompass biology, geology, biotechnology and allied sciences with cutting edge applications for sustainable mitigation of As epidemic. Discovery of As hyperaccumulating plants that uptake and concentrate large amounts of this toxic metalloid in their shoots or roots offered new hope to As phytoremediation, solar power based nature's own green remediation. This review focuses on how phytoremediation and bioremediation can be merged together to form an integrated phytobial remediation which could synergistically achieve the goal of large scale removal of As from soil, sediment and groundwater and overcome the drawbacks of the either processes alone. The review also points to the feasibility of the introduction of transgenic plants and microbes that bring new hope for more efficient treatment of As. The review identifies one critical research gap on the importance of remediation of As contaminated groundwater not only for drinking purpose but also for irrigation purpose and stresses that more research should be conducted on the use of constructed wetland, one of the most suitable areas of application of phytobial remediation. Finally the review has narrowed down on different phytoinvestigation and phytodisposal methods, which constitute the most essential and the most difficult part of pilot scale and field scale applications of phytoremediation programs.

Uptake Kinetics of Arsenic in Upland Rice Cultivar Zhonghan 221 Inoculated with Arbuscular Mycorrhizal Fungi

Arbuscular mycorrhizal fungi (AMF) appear to be highly associated with arsenic (As) uptake in host plants because arsenate (As(V)) and phosphorus (P) share the same transporter, whereby AMF can enhance P uptake. A short-term experiment was conducted for low- (0 to 0.05 mM As) and high-affinity (0 to 2.5 mM As) uptake systems, to investigate the AMF role on As uptake mechanism in plants, which may explain As uptake kinetics in upland rice cultivar: Zhonghan 221. When concentration of As ranged from 0 to 0.05 mM, Funneliformis geosporum (Fg) significantly decreased arsenite (As(III)) and monomethylarsonicacid (MMA) uptake when (p < 0.05) compared to non-mycorrhizal (NM) treatment, since the major route for (As(III)) in rice roots-rice silicon transporter Lsi1 would be influenced by Fg inoculation at high As concentrations. Fg can also reduce As(V) uptake significantly (p < 0.05) under both uptake systems relative to NM treatment, whereas, Funneliformis mosseae (Fm) increased As(V) and MMA uptake in rice roots, with MMA uptake rate generally lower than As(III) and As(V). Using suitable AMF species inoculation with rice, As uptake and accumulation in rice grains can be reduced and the risk to human health, once consumed, can be minimized.

A critical review of the arsenic uptake mechanisms and phytoremediation potential of Pteris vittata

The discovery of the arsenic hyperaccumulator, Pteris vittata (Chinese brake fern), has contributed to the promotion of its application as a means of phytoremediation for arsenic removal from contaminated soils and water. Understanding the mechanisms involved in arsenic tolerance and accumulation of this plant provides valuable tools to improve the phytoremediation efficiency. In this review, the current knowledge about the physiological and molecular mechanisms of arsenic tolerance and accumulation in P. vittata is summarized, and an attempt has been made to clarify some of the unresolved questions related to these mechanisms. In addition, the capacity of P. vittata for remediation of arsenic-contaminated soils is evaluated under field conditions for the first time, and possible solutions to improve the remediation capacity of Pteris vittata are also discussed.

Mycorrhizal colonization affects the elemental distribution in roots of Ni-hyperaccumulator Berkheya coddii Roessler

The effect of arbuscular mycorrhizal fungi (AMF) on the distribution and concentration of elements in roots of Ni-hyperaccumulating plant Berkheya coddii was studied. Micro-PIXE (particle-induced X-ray emission) analysis revealed significant differences between AMF-inoculated and non-inoculated plants as well as between main and lateral roots. The accumulation of P, K, Mn and Zn in the cortical layer of lateral roots of inoculated plants confirmed the important role of AMF in uptake and accumulation of these elements. Higher concentration of P, K, Fe, Ni, Cu and Zn in the vascular stele in roots of AMF-inoculated plants than in the non-inoculated ones indicates more efficient translocation of these elements to the aboveground parts of the plant. These findings indicate the necessity of including the influence of AMF in studies on the uptake of elements by plants and in industrial use of B. coddii for Ni extraction from polluted soils.

Can arbuscular mycorrhizal fungi improve grain yield, As uptake and tolerance of rice grown under aerobic conditions?

The effects of arbuscular mycorrhizal fungi (AMF) -Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg(-1). In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses.

Synergistic effects of arbuscular mycorrhizal fungi and phosphate rock on heavy metal uptake and accumulation by an arsenic hyperaccumulator

The effects of arbuscular mycorrhizal (AM) fungi and phosphate rock on the phytorextraction efficiency of a hyperaccumulator (Pteris vittata) and a non-hyperaccumulator (Cynodon dactylon) plant were studied. Both seedlings were planted in As contaminated soil under different treatments [(1) control (contaminated soil only), (2) indigenous mycorrhizas (IM), (3) mixed AM inoculum [indigenous mycorrhiza + Glomus mosseae (IM/Gm)] and (4) IM/Gm + phosphate rock (P rock)] with varying intensities (40%, 70% and 100%) of water moisture content (WMC). Significant As reduction in soil (23.8% of soil As reduction), increase in plant biomass (17.8 g/pot) and As accumulation (2054 mg/kg DW) were observed for P. vittata treated with IM/Gm + PR at 100% WMC level. The overall results indicated that the synergistic effect of mycorrhiza and P rock affected As subcellular distribution of the hyperaccumulator and thereby altered its As removal efficiency under well-watered conditions.