Uptake Of Mineral Elements Research Articles

Decoding the Double Stress Puzzle: Investigating Nutrient Uptake Efficiency and Root Architecture in Soybean Under Heat- and Water-Stresses.

In the context of climate change, associated with increasingly frequent water deficits and heat waves, there is an urgent need to maintain the performance of soybean, a leading legume crop worldwide, before its yield declines. The objective of this study was to explore which plant traits improve soybean tolerance to heat and/or water stress, with a focus on traits involved in plant architecture and nutrient uptake. For this purpose, two soybean genotypes were grown under controlled conditions in a high-throughput phenotyping platform where either optimal conditions, heat waves, water stress or both heat waves and water stresses were applied during the vegetative stage. By correlating architectural to functional traits, related to water, carbon allocation and nutrient absorption, we were able to explain the stress susceptibility level of the two genotypes. We have shown that water flow in the plant is central to the uptake and allocation of mineral elements in the plant, despite its modulation by stress and in a genotype-dependent manner. This cross-analysis of plant ecophysiology and plant nutrition under different stresses provides new information, especially on the importance of mineral elements in the different plant organs, and can inform future crop design, particularly under changing climatic conditions.

Genome-wide identification and expression analysis of CASPL gene family in Zea mays (L.).

Casparian strip membrane domain proteins like (CASPL), exhibit profound associations with root development, stress responsiveness and mineral element uptake in plants. Nonetheless, a comprehensive bioinformatics analysis of the ZmCASPL gene family in maize remains unreported. In the study, we have identified 47 ZmCASPL members at the whole-genome level, systematically classifying them into six distinct groups. Furthermore, our analysis revealed that the same group of ZmCASPL contains similar gene structures and conserved motifs. Duplication events showed whole genome duplication (WGD) and tandem duplication (TD) contribute to the generation of the ZmCASPL gene family together in maize, but the former plays a more prominent role. Furthermore, we observed that most ZmCASPL genes contain MYB-binding sites (CAACCA), which are associated with the Casparian strip. Utilizing RNA-seq data, we found that ZmCASPL21 and ZmCASPL47 are specifically highly expressed only in the roots. This finding implies that ZmCASPL21 and ZmCASPL47 may be involved in the Casparian strip development. Additionally, RNA-seq analysis illuminated that drought, salt, heat, cold stresses, low nitrogen and phosphorus conditions, as well as pathogen infection, significantly impact the expression patterns of ZmCASPL genes. RT-qPCR revealed that ZmCASPL 5/13/25/44 genes showed different expression patterns under PEG and NaCl treatments. Collectively, these findings provide a robust theoretical foundation for further investigations into the functional roles of the ZmCASPL gene family in maize.

Investigation of the effects and mechanisms of manganese-based NMs on rice growth.

Manganese-based (Mn-based) nanomaterials (NMs) have great potential as alternatives to conventional Mn fertilizers. Yet, its environmental risks and effects on plant growth are not completely well understood. This study investigated the physiological effects of manganese dioxide (MnO2) and manganese tetroxide (Mn3O4) NMs on inter-root exposure (0-500 mg/L) of hydroponically grown rice. The results showed that on inter-root exposure, 50 mg/L Mn-based NMs promoted the uptake of mineral elements and enhanced the enzymatic activities of antioxidant systems (CAT and SOD) in rice, whereas 500 mg/L Mn3O4 NMs disrupted the mineral element homeostasis and led to phytotoxicity. The promotion effect of MnO2 NMs was better, firstly because MnO2 NMs treatment had lower Mn content in the plant than Mn3O4 NMs. In addition, MnO2 NMs are more transported and absorbed in the plant in ionic form, while Mn3O4 NMs exist in granular form. MnO2 NMs and Mn3O4 NMs both can be used as nano-fertilizers to improve the growth of rice by inter-root application, but the doses should be carefully selected.

The effects of different doses of lanthanum-modified bentonite in combination with a submerged macrophyte (Vallisneria denseserrulata) on phosphorus inactivation and macrophyte growth: A mesocosm study

The combination of chemical phosphorus (P) inactivation and submerged macrophyte transplantation has been widely used in lake restoration as it yields stronger effects than when applying either method alone. However, the dose effect of chemical materials on P inactivation when used in combination with submerged macrophytes and the influences of the chemicals used on the submerged macrophytes growth remain largely unknown. In this study, we investigated P inactivation in both the water column and the sediment, and the responses of submerged macrophytes to Lanthanum modified bentonite (LMB) in an outdoor mesocosm experiment where Vallisneria denseserrulata were transplanted into all mesocosms and LMB was added at four dosage levels, respectively: control (LMB-free), low dosage (570 g m−2), middle dosage (1140 g m−2), and high dosage (2280 g m−2). The results showed that the combination of LMB dosage and V. denseserrulata reduced TP in the water column by 32%–38% compared to V. denseserrulata alone, while no significant difference was observed among the three LMB treatments. Porewater soluble reactive P, two-dimensional diffusive gradient in thin films (DGT)-labile P concentrations, and P transformation in the 0–1 cm sediment layer exhibited similar trends along the LMB dosage gradient. Besides, LMB inhibited plant growth and reduced the uptake of mineral elements (i.e., calcium, manganese, iron, and magnesium) in a dosage-dependent manner with LMB. LMB may reduce plant growth by creating a P deficiency risk for new ramets and by interfering with the uptake of mineral elements. Considering both the dose effect of LMB on P inactivation and negative effect on macrophyte growth, we suggest a “small dosage, frequent application” method for LMB application to be used in lake restoration aiming to recover submerged macrophytes and clear water conditions.

Identification of novel germplasm and genetic loci for enhancing mineral element uptake in soybean

Bioavailability, uptake, and spatial distribution of essential and toxic mineral elements are pivotal factors that govern crop growth, development, and productivity. Soybean is a major leguminous crop globally, and yield losses are commonly attributed to various abiotic factors, including nutrient deficiencies or the influence of toxic minerals in the soil. Therefore, understanding the molecular basis of differential mineral element uptake, translocation, and accumulation in soybean is vital for developing improved cultivars. Here, we used portable X-ray fluorescence (p-XRF) for rapid and high-throughput mineral element profiling of a diverse set of soybean germplasm using leaves, stem, root, and seed tissues. Genome-wide association (GWAS) was performed on the element profiles of 219 soybean accessions, revealing lines with notable two to tenfold difference in various mineral nutrient uptake. These identified lines represent valuable genetic resources for germplasm development and gene discovery. The GWAS analysis pinpointed significant genomic loci and haplotypes associated with accumulation of aluminum (Al), silicon (Si), iron (Fe), and manganese (Mn). Remarkably, genes associated with the transport of solutes, metals, and ions have been pinpointed, indicating their potential involvement in the nutrient uptake and soybean improvement. To gain functional insights, Si deposition, allelic variants and expression of three Si transporter genes was studied in greater details. The high Si accumulating line PI548452 showed 12-fold increase in leaf Si content compared to low Si lines. Expression of HiSil2b and HiSil2c effluxer genes showed root and leaf specific expression, respectively, providing evidence for tissue specific Si transport and the basis for precise management of Si uptake to improve abiotic and biotic stresses. In summary, this study uncovered the novel accessions, haplotypes, allelic diversity, and the potential candidate genes underpinning the mineral nutrient accumulation in soybean.

Effects of fullerene C60 on the uptake of nitrogen and mineral elements in crops using the synchrotron radiation microscopic X-ray fluorescence spectrometry (SR-μXRF) and stable isotope labeling

The unique characteristics of fullerene (C60) have attracted great attention in the agricultural field. However, it remains unclear about its potential effects of nitrogen sources and the uptake of various...

An experimental study on the effects copper and lead on the seedlings of some economically important vegetable species

Bioaccumulation of toxic heavy metals in vegetables is closely related to the problems of safety concerns as they negatively affect plants in particular those consumed by the humans. Among the food systems the vegetables are the most noticeable foods affected by environmental pollution. Vegetables can take up the metals like copper and lead and store them in excessive levels. Keeping this in view this investigation was undertaken to study the effect of copper and lead concentrations (20, 40, 80, 160, 240, 320, 640, and 1280 µM) and assess their toxic affects on germination and seedling growth at early stages of eight vegetable cultivars; kidney bean, peas, black-eyed bean, artichoke, kale, lettuce, rocket and radish. The results were evaluated by multivariate analysis of variance and Pearson correlation statistical analysis. Our results indicate that the seeds of the vegetables studied by us are generally tolerant to both copper as well lead, except higher concentration exposures which showed no improvement when applied to artichoke (for Cu 1280 µM) and lettuce seeds (Cu 1280 µM; Pb 1280 µM). An application of copper and lead ended up with a decrease in barium, calcium, iron, magnesium, manganese, sodium and zinc content in all seedlings studied. In all vegetables exposed to copper and lead a promotion in copper and lead accumulation was recorded. There was a decrease in nutrient element intake which interrupted the mineral element uptake in the seedlings.

Enhancing environmental monitoring: utilizing plant and soil assays to track pollution in a Turkish organized industrial zone

The aim of the current investigation was to determine the concentration of different metals in Mentha spicata L. subsp. tomentosa plants and soils in order to highlight the pollution level in a Turkish Organized Industrial Zone in Dilovasi District, in Kocaeli City. The concentration of metals in plant and soil samples were examined. When the soil values were examined, the highest cadmium, chromium, copper, iron, nickel, and lead levels were collected from the location which is hosting numerous industrial facilities. All elements except boron and copper, exceeded normal limits in the leaf samples while cadmium, chromium, iron, nickel, lead, and zinc reached “toxic levels” in leaf samples. Heavy metals were accumulated in leaves more than rhizomes. Mineral element uptake and accumulation were affected from heavy metal amounts, especially in rhizomes. Although washing procedure notably reduced the concentration of some heavy metals in leaves samples, the reduced values were higher than acceptable levels in some locations of the district. According to the data, it may be said that the region, especially its industrialized parts are heavily polluted by heavy metals. Moreover, in the accordance with the fact that, the highest values of elements were determined in regions having considerable industrial activity such as metal and plastic processing facilities. Additionally, Mentha spicata plants exhibited higher heavy metal values in areas with high heavy metal content in the soil, and lower heavy metal values in areas with low heavy metal concentration. These findings indicate that Mentha spicata, a plant known for its medicinal and culinary uses, can be considered as an effective biomonitor for heavy metal pollution in the region. Consequently, constant inspection is required to prevent the excessive buildup of metals in the region and similar areas with comparable characteristics in terms of human life.

Salinity stress amelioration and morpho-physiological growth stimulation by silicon priming and biochar supplementation in Chenopodium quinoa

The effect of silicon (Si) priming and soil amendment with biochar (BC) was analysed in Chenopodium quinoa under normal and salinity stressed conditions. Reduced growth parameters, chlorophyll content, and photosynthesis under salinity stress were significantly ameliorated by Si priming and soil amendment with BC. Applied Si and BC treatment also enhanced the chlorophyll content, stomatal conductance, transpiration rate, net photosynthesis, and maximal photochemical efficiency. In addition to this, Si and/or BC amendments alleviated the oxidative damage by reducing the generation of toxic reactive oxygen species including hydrogen peroxide and superoxide. Moreover, the activities of antioxidant enzymes and the content of ascorbate and glutathione increased significantly in Si and BC treated plants reflecting efficient alleviation of oxidative damage. Besides, the content of compatible osmolytes was increased in Si and/or BC treated seedlings, thereby contributing to improved growth and salinity tolerance by maintaining higher leaf water potential and water use efficiency. Si and BC treatment increased the uptake of key mineral elements. Moreover, salinity induced decline in the nutritional components of seeds of C. quinoa were considerably increased under Si and BC treatments.

Symbiosis of Arbuscular Mycorrhizal Fungi and Lycium barbarum L. Prefers NO3− over NH4+

Nitrogen (N) is an essential nutrient that plants require and is, most of the time, limited in different terrestrial ecosystems. Forming symbioses with plants, arbuscular mycorrhizal (AM) fungi improve mineral element uptake and the net primary production of plants. Recent reports have suggested that AM fungi mediate N uptake in plants. However, there are fewer studies on the influence of AM fungi on the response of Lycium barbarum, a medicinal plant in northwest China, under different N-addition conditions. In this study, the effect of Rhizophagus irregularis, N forms (NO3− and NH4+), and N levels (1.5, 7.5, 15, 30 mM) on the performance of L. barbarum was evaluated through a pot experiment. The application of R. irregularis significantly improved L. barbarum biomass, net photosynthetic rate, and root tissue viability under adequate NO3− and NH4+ supplies, and mycorrhizal plants showed better performance under NO3− supply. AM colonization enhanced N acquisition under adequate NO3− supply and strongly induced the expression of LbAMT3-1 in L. barbarum roots. Based on these results, we propose that NO3−-dominated N supply favors mycorrhizal symbiosis to a greater extent than NH4+; this study provides a basis for maintaining beneficial AM symbiosis during nitrogen fertilizer use in arable land.

Effects of Arbuscular Mycorrhizal Fungi on the Physiology and Saponin Synthesis of Paris polyphylla var. yunnanensis at Different Nitrogen Levels

Arbuscular mycorrhizal fungi (AMF) are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots. Nitrogen (N), as an important mineral element, can directly affect plant growth and development at different N levels. It has been confirmed that inoculation with AMF can improve the efficiency of N utilization by plants. However, there are still fewer reports on the dynamic relationship between arbuscular mycorrhizal and plant secondary metabolites at different nitrogen levels. In this experiment, the physiological indexes and genes related to saponin synthesis were determined by applying different concentration gradients of nitrogen to the medicinal plant P. polyphylla var. yunnanensis infested by AMF as the test material. It was found that nitrogen addition increased the biomass, chlorophyll content, and nutrient content of above- and below-ground plant parts and increased the content of saponin content of P. polyphylla var. yunnanensis to some extent, but AMF inoculation increased the saponin content of P. polyphylla var. yunnanensis more significantly. AMF inoculation also promoted the expression of genes related to the saponin synthesis pathway, including 3-hydroxy-3-methylglutaryl coenzyme A synthase (HMGS), squalene epoxidase 1 (SE1), and cycloartenol synthase (CAS), which is in according with the accumulation of saponin in plants. It also may increase the saponin content of AMF plants by altering the expression of P450s and UGTs related to saponin synthesis.

Arbuscular mycorrhizal fungi regulate plant mineral nutrient uptake and partitioning in iron ore tailings undergoing eco-engineered pedogenesis

Excess available K and Fe in Fe-ore tailings with organic matter and water-deficiencies may restrain plant colonization and growth, which hinders the formation of eco-engineered soil from these tailings for sustainable and cost-effective mine site rehabilitation. Arbuscular mycorrhizal (AM) fungi are widely demonstrated to assist plant growth under various unfavorable environments. However, it is still unclear whether AM symbiosis in tailings amended with different types of plant biomass, and under different water conditions could overcome the surplus K and Fe stress for plants in Fe ore tailings, and if so, by what mechanisms. Here, host plants (Sorghum spp. Hybrid cv. Silk) either colonized or non-colonized by the AM fungi (Glomus spp.), were cultivated in Lucerne hay- (C: N ratio of 18, LH) or Sugarcane mulch- (C: N ratio of 78, SM) amended Fe-ore tailings under well-watered (55% water holding capacity (WHC) of tailings) or water-deficient (30% WHC of tailings) conditions. Mycorrhizal colonization, plant growth, and mineral elemental uptake and partitioning were examined. The results indicated that AM fungal colonization improved plant growth in tailings amended with plant biomass under water deficient conditions. AM fungal colonization enhanced plant mineral element uptake, especially P, both in the LH- and SM-amended tailings regardless of water condition. Additionally, AM symbiosis development restrained the translocation of excess elements (i.e., K and Fe) from roots to shoots, thereby relieving their phytotoxicity. AM roles in phosphorus uptake, and excess elemental partitioning were greater in tailings with LH amendment than those with SM amendment. Water deficiency weakened AM fungal colonization and functions in terms of mineral element uptake and partitioning. These findings have highlighted the vital role AM fungi played in regulating plant growth and nutrition status in Fe-ore tailings technosols, providing the basis for involvement of AM fungi in the eco-engineered pedogenesis of iron ore tailings.

Investigating the vegetative growth and mineral elements uptake by Damask rose irrigated with various levels of Sodium Chloride

Investigating the vegetative growth and mineral elements uptake by Damask rose irrigated with various levels of Sodium Chloride

Aboveground herbivory does not affect mycorrhiza-dependent nitrogen acquisition from soil but inhibits mycorrhizal network-mediated nitrogen interplant transfer in maize.

Arbuscular mycorrhizal fungi (AMF) are considered biofertilizers for sustainable agriculture due to their ability to facilitate plant uptake of important mineral elements, such as nitrogen (N). However, plant mycorrhiza-dependent N uptake and interplant transfer may be highly context-dependent, and whether it is affected by aboveground herbivory remains largely unknown. Here, we used 15N labeling and tracking to examine the effect of aboveground insect herbivory by Spodoptera frugiperda on mycorrhiza-dependent N uptake in maize (Zea mays L.). To minimize consumption differences and 15N loss due to insect chewing, insect herbivory was simulated by mechanical wounding and oral secretion of S. frugiperda larvae. Inoculation with Rhizophagus irregularis (Rir) significantly improved maize growth, and N/P uptake. The 15N labeling experiment showed that maize plants absorbed N from soils via the extraradical mycelium of mycorrhizal fungi and from neighboring plants transferred by common mycorrhizal networks (CMNs). Simulated aboveground leaf herbivory did not affect mycorrhiza-mediated N acquisition from soil. However, CMN-mediated N transfer from neighboring plants was blocked by leaf simulated herbivory. Our findings suggest that aboveground herbivory inhibits CMN-mediated N transfer between plants but does not affect N acquisition from soil solutions via extraradical mycorrhizal mycelium.

Cultivar-specific response of rhizosphere bacterial community to uptake of cadmium and mineral elements in rice (Oryza sativa L.)

Toxic metal-contaminated farmland from Cadmium (Cd) can enhance the accumulation of Cd and impair the absorption of mineral elements in brown rice. Although several studies have been conducted on Cd exposure on rice, little has been reported on the relationship between Cd and mineral elements in brown rice and the regulatory mechanism of rhizosphere microorganisms during element uptake. Thus, a field study was undertaken to screen japonica rice cultivars with low Cd and high mineral elements levels, analyze the quantitative relationship between Cd and seven mineral elements, and investigate the cultivar-specific response of rice rhizosphere bacterial communities to differences in Cd and mineral uptake in japonica rice. Results showed that Huaidao-9 and Xudao-7 had low Cd absorption and high amounts of mineral nutrient elements (Fe, Zn, Mg, and Ca, LCHM group), whereas Zhongdao-1 and Xinkedao-31 showed opposite accumulation characteristics (HCLM group). Stepwise regression analysis showed that zinc, iron, and potassium are the key minerals that affect Cd accumulation in japonica rice and zinc was the most important factor, accounting for 68.99 %. The accumulation of Cd and mineral elements is potentially associated with rhizosphere soil bacteria. Taxa enriched in the LCHM rhizosphere (phyla Acidobacteriota and MBNT15) indicated the high nutrient characteristics of the soil and reduced activity of Cd in soil. The HCLM rhizosphere was highly colonized by metal-activating bacteria (Actinobacteria), lignin-degrading bacteria (Actinobacteria and Chlorofexi), and bacteria scavenging nutrients and trace elements (Anaerolinea and Ketobacter). Moreover, the differences in the uptake of Cd and mineral elements affected predicted functions of microbial communities, including sulfur oxidation and sulfur derivative formation, human or plant pathogen, and functions related to the iron oxidation and nitrate reduction. The results indicate a potential association of Cd and mineral elements uptake and accumulation with rhizosphere bacteria in rice, thus providing theoretical basis and a new perspective on the maintenance of rice security and high quality simultaneously.

The ameliorative effect of hydrogen sulfide on cadmium toxicity and oxidative stress damage in garlic (Allium sativum) seedlings

• H 2 S reduces the uptake and accumulation of cadmium in garlic plants. • H 2 S reducing Cd oxidative damages by adjusting antioxidant enzyme system. • H 2 S considerably balanced Fe and Na in garlic seedlings. • H 2 S ameliorator improved the photosynthetic rate of garlic seedlings. Hydrogen sulfide (H 2 S) was identified as a novel signaling molecule that plays roles in plant growth and responses to abiotic stresses. However, information regarding its role in cadmium (Cd) detoxification and possible beneficial effects against oxidative damage in garlic plants is lacking. In this study, garlic ( Allium sativum ) seedlings were grown hydroponically at 0, 10 −4 , 10 −3 and 10 −2 M of cadmium chloride (CdCl 2 ) and 0, 200 µM concentrations of sodium hydrosulfide (NaHS). Cadmium stress caused growth inhibition and biomass reduction, which was related to high accumulation of cadmium in roots and shoots, depletion of chlorophyll contents, decrease of photosynthetic parameters and imbalanced in essential elements. These changes were accompanied by increasing activities of superoxide dismutase and ascorbate peroxidase enzymes while catalase enzyme activity decreased. The treatment with H 2 S ameliorator reduced Cd accumulation in seedling and improved photosynthetic rate of plants. This conclusion was supported by the increase of superoxide dismutase and ascorbate peroxidase activities as well as the balanced to mineral element uptake. Based on the results, it can be concluded that exogenous H 2 S has a positive effect on reducing Cd oxidative damages by adjusting antioxidant enzyme system and balances in nutrient element uptake, thus proposing H 2 S as a candidate for managing toxicity of cadmium in garlic plants.

Effect of sodium chloride on physiological, biochemical traits, and mineral nutrition inhibition of peanut varieties in large temperature fluctuations

Peanut has a high nutritional value which would be influenced by soil salinization that arises because of climate change. In this paper, the effects of salinity on morphological, physiological biochemical parameters and mineral absorption inhibition of the three varieties cultivated in Cameroon, namely ICGV86003 (V1), Metchicha (V2), and JL 24 (V3) were evaluated under large temperature fluctuations. Plants of each variety were grown at four concentrations of Wacquant's nutrient solution 0, 40, 80, and 120 mM of NaCl 20 days after germination under an unstable environment. The experiment pots were arranged in a completely randomized design with five replicates. The results showed that the three studied peanut varieties present distinct indicators for salt tolerance. Total Leaf Area (TLA), Fresh Weight (FW), and Relative Water Content (RWC) decreased from 80 mM, 40mM, and 80 mM of NaCl respectively. Bound water (BW) increased from 40 mM of NaCl in all varieties. Total sugars, total protein, and peroxidase content increased from 40 mM of NaCl, while polyphenol content increased from 40 mM NaCl in the V1 variety and 80 mM of NaCl in the V2 and V3 varieties. In addition, nutrient elements left in the soil were elevated from 40 mM of NaCl while N was reduced under the same salt conditions for V2, V3, and V1 respectively. These results suggest that the adaptive mechanism of the studied varieties of peanut to salt stress under temperature fluctuations reduces the uptake of mineral elements by the plant and is at the origin of the poor organoleptic quality of fruits.

Linking root morphology and anatomy with transporters for mineral element uptake in plants

Linking root morphology and anatomy with transporters for mineral element uptake in plants

Effect of cerium on the production of reactive oxygen species in the root of Arabidopsis thaliana: An in vitro study.

In the current study, the effect of trivalent cerium (Ce3+ ) on the production of reactive oxygen species (ROS) was investigated in the root of Arabidopsis thaliana by an in vitro study. The roots of A. thaliana were exposed with 0, 1, and 5μmol/L Ce3+ for 12 h in vitro. It was found that the level of H2 O2 , O2 .- , and ·OH was enhanced by 5μmol/L Ce3+ , but reduced by 1μmol/L Ce3+ . The activities of peroxidase (POD), catalase (CAT), and superoxidase dismutase (SOD) were enhanced by 1μmol/L Ce3+ , but reduced by 5μmol/L Ce3+ . Moreover, we used a laser-scanning confocal microscopy to detect the changes of ROS in the root cells of A. thaliana by using a fluorochrome 2',7'-dichlorofluorescein diacetate (H2 DCF-DA). It showed that the level of ROS was declined in the root cells treated by 1μmol/L Ce3+ , but the oscillation of ROS was found in the root cells treated with 5μmol/L Ce3+ . In addition, REEs affect the uptake of mineral elements, which may be related to the oxidative stress in the cells of roots. In all, the data of our study indicated that the appropriate concentration of Ce3+ exhibited an anti-oxidation property and improved the defense system in the root cells of A. thaliana.

Effects of Mn2+ on Cd accumulation and ionome in rice and spinach.

Health risks caused by food containing Cd is a concern worldwide. Interaction between Mn and Cd has been widely studied in normal hydroponic solution with high ion activities (e.g., the study on sharing of transporter Natural Resistance-Associated Macrophage Protein 5 between Mn and Cd in rice [Oryza sativa L.]). However, interaction of Mn and Cd in crops like rice and spinach (Spinacia oleracea L.) at field ion activity level is still unknown. Thus, an ethyleneglycoltetraacetate-buffered solution experiment was conducted to explore the effect of Mn on the uptake and accumulation of Cd and other mineral elements in rice and spinach. In rice, antagonism of Mn and Cd was only observed in roots at deficient and toxic levels of external Mn2+ . Compared with those at Mn2+ sufficiency (pMn2+ 6.7-5.3), average root Cd levels were elevated significantly by 1.85-3.05 times at Mn2+ deficiency (pMn2+ 8.2) but decreased by 1.57-2.59 times at Mn2+ toxicity (pMn2+ 4.8). The antagonism between Mn and K/Mg in rice shoots might be caused by their common role in physiological processes in plants. Antagonism of Mn/Ni in spinach in this work was consistent with their shared transporters in dicots. Results about the antagonism of root Cd/Mn at Mn2+ deficiency suggest that sufficiently available Mn2+ is significant to reduce Cd uptake in rice under field levels of ion activity, but it was not for spinach because the change of tissue Cd was insignificant with the increase of Mn2+ activity from deficiency to toxicity.