Analysis of organic acids in selected forest litters of Northeast China

Larch (Larix olgensis), Manchurian ash (Fraxinus mandshurica), Korean pine (Pinus koraiensis) and White birch (Betula platyphylla) are the major planting species in northeast China. The samples of forest litters were collected from the stands of the above 4 species in Laoyeling and Jianlagou experiment stations of Maorshan Exp. Forest Farm (45?2-45?0N, 127?0-127?8E), Northeast Forestry University, in early October 2002. Quantitative analysis and qualitative analysis were carried out on the organic acids existing in freshly fallen litters (L layer) and hemi-decomposed litters (F layer) of the four forest species by using Gas Chromatogram system. A wide variety of organic acids were identified, including oxalic, malonic, fumaric, succinic, maleic, malic, citric, C16:0, C18:0, C18:1, C18:2, C18:3 and C20:0 acids. In respect of L litters of all samples, the oxalic acid content (over 30 mg/g) was the highest of the seven low-molecular-weight organic acids identified, while the content of oleic or linoleic (above 40 mg/g) was found to be highest among the six high aliphatic acids identified. As to F litters, oxalic acid content was also the highest, followed by linoleic and oleic. For the same tree species or the same forest, the kinds and contents of organic acids in L litters were more abundant than that in F litters.

Multilevel analysis of the central-peripheral-target organ pathway:contributing to recovery after peripheral nerve injury

Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and disabilities.Research on the pathogenesis of peripheral nerve injury has focused on pathological changes at individual injury sites,neglecting multilevel pathological analysis of the overall nervous system and target organs.This has led to restrictions on current therapeutic approaches.In this paper,we first summarize the potential mechanisms of peripheral nerve injury from a holistic perspective,covering the central nervous system,peripheral nervous system,and target organs.After peripheral nerve injury,the cortical plasticity of the brain is altered due to damage to and regeneration of peripheral nerves;changes such as neuronal apoptosis and axonal demyelination occur in the spinal cord.The nerve will undergo axonal regeneration,activation of Schwann cells,inflammatory response,and vascular system regeneration at the injury site.Corresponding damage to target organs can occur,including skeletal muscle atrophy and sensory receptor disruption.We then provide a brief review of the research advances in therapeutic approaches to peripheral nerve injury.The main current treatments are conducted passively and include physical factor rehabilitation,pharmacological treatments,cell-based therapies,and physical exercise.However,most treatments only partially address the problem and cannot complete the systematic recovery of the entire central nervous system-peripheral nervous system-target organ pathway.Therefore,we should further explore multilevel treatment options that produce effective,long-lasting results,perhaps requiring a combination of passive(traditional)and active(novel)treatment methods to stimulate rehabilitation at the central-peripheral-target organ levels to achieve better functional recovery.

Analysis of Organic Acids Accumulated in Kochia Scoparia Shoots and Roots by Reverse-phase High Performance Liquid Chromatography Under Salt and Alkali Stress

Several organic acids accumulated in Kochia Scoparia shoots and roots were studied by means of reverse-phase high performance liquid chromatography with a C18 column. Five types of binary organic acids were separated. The organic acid concentrations were determined in K. Scoparia seedlings stressed by saline （NaCI） and alkaline （NaHCO3） at the same Na^＋ concentration. Concentrations of organic acids are stimulated by alkaline because the cells will adjust their pH values through the accumulation of organic acids, when the environment is basic. The concentrations of oxalic acid and succinic acid are higher than those of other organic acids, including tartaric acid and malic acid, and the concentration of citric acid is the lowest. The concentrations of the organic acids in the roots are higher than those in the shoots under salt（NaCI） stress, but the results are opposite while the roots are under alkali （ NaHCO3 ） stress. This indicates that there are different adaptive strategies for K. Scopar/a seedlings in organic acid metabolism under salt and alkali stress.

Chitosan Biopolymers for Analysis of Organic Acids in Aquatic Environments of Treatment Wetlands

Herein, we report on the use of chitosan-based engineered materials for the sequestration of naphthenic acid fraction compounds (NAFCs) and other species (matrix) in oil sands process-affected water (OSPW) in order to improve monitoring of NAFCs after phytoremediation. Chitosan pellets (CPs) were cross linked with glutaraldehyde (GLU) at variable feed ratios and characterized using thermogravimetric analysis (TGA). Sorption studies at equilibrium and kinetic conditions were carried on OSPW extract, raw and treated wetland samples. The materials were shown to have similar sorption capacity for NAFCs but with variable selectivity of the species in the complex mixture. As well, the matrix uptake varied according to the type of OSPW. Overall, CP in its native form outperformed the cross linked CP pellets, as evidenced by a reduction in matrix effects.

Process design and economic analysis of methacrylic acid extraction for three organic solvents

In this work,a techno-economic study for the solvent based extraction of methacrylic acid from an aqueous solution is presented.The involved phase equilibrium calculations in process design are verified by measured experimental data.First,experiments are conducted with different solvent candidates to measure LLE(liquid–liquid equilibrium)data and to establish the effects of extraction temperature and dosage of solvent.Next,the binary interaction parameters for the UNIQUAC model to be used for equilibrium calculations are fine-tuned with measured data.Then,a process for the solvent based extraction of methacrylic acid recovery is designed and verified through simulation with the regressed UNIQUAC model parameters.The optimal configuration of the process flowsheet is determined by minimizing the total annualized cost.Among the three solvent candidates considered-cyclohexane,hexane and toluene-the highest efficiency and the lowest total annualized cost is found with toluene as the solvent.

Effect of root derived organic acids on the activation of nutrients in the rhizosphere soil

Four types of soils, including brown coniferous forest soil, dark brown soil, black soil, and black calic soil, sampled from three different places in northeast China were used in this test. The functions of two root-derived organic acids and water were simulated and compared in the activation of mineral nutrients from the rhizosphere soil. The results showed that the organic acids could activate the nutrients and the activated degree of the nutrient elements highly depended on the amount and types of the organic acid excreted and on the physiochemical and biochemical properties of the soil tested. The activation effect of the citric acid was obviously higher than that of malic acid in extracting Fe, Mn, Cu, and Zn for all the tested soil types. However, the activation efficiencies of P, K, Ca, and Mg extracting by the citric acid were not much higher, sometimes even lower, than those by malic acid. The solution concentration of all elements increased with increase of amount of the citric acid added.

Organic Acids Secreted from Plant Roots under Soil Stress and Their Effects on Ecological Adaptability of Plants

[Objective] In this study,the secretion of organic acids from plant roots under soil nutrient and water stress and the effects of organic acids on ecological adaptability of plants were investigated,which provided theoretical basis for improving the adaptability of plants to a variety of stress conditions.The results showed that,under nutrient and water stress,the content of organic acids secreted from plant roots increased significantly as a common active adaptive response.Organic acids could improve the activities of a variety of antioxidant enzymes,contents of osmotic regulatory substances,contents of chlorophyll and photosynthesis levels,promote nutrient absorption and transportation in plants,and ultimately contribute to plant growth and biomass accumulation,reduce the toxicity of stress conditions to plants and improve the stress resistance and adaptability of plants.

Analysis and Pollution Assessment on the Dissolved Organic Matter in the Sediment of Hydro-fluctuation Belt(Yunyang Part)

By using the ultraviolet absorption spectrum,the fluorescence spectrum and three dimensional fluorescence spectra,the composition of dissolved organic matter(DOM) and the humification degree,etc.in the sediment of hydro-fluctuation belt(Yunyang part) were analyzed.The relationship between the test parameters and the pollution degree in the region was discussed.The research results of UV spectrum data E3/E4 showed that in 4 sampling sites which included Huangshi Town,Gaoyang Town,Shuangjiang Town and Quma Town,the humification degree in the sediment of hydro-fluctuation belt in Shuangjiang Town sampling site was lower,and the aromaticity was smaller.Moreover,the effect of human factor was comparatively smaller.The fluorescence index value which represented the source of humus in DOM was 1.62-1.88.It showed that the biological and terrestrial source both existed.Three dimensional spectra results showed that the pollution degrees in 4 sampling sites were all smaller,and some prevention measures should be taken early.

Effects of Exogenous Organic Acids on Dehydrogenase Activity in Dark Brown Forest Soils under Nutrient Deficiency

Objective] This study aimed to investigate the effects of exogenous or-ganic acids on dehydrogenase activity in dark brown forest soils under nutrient defi-ciency. [Method] Different proportions of A1 and B horizon dark brown forest soils （A1∶B=1∶2） were utilized to establish soil conditions with nutrient deficiency for cultivation of Larix olgensis seedlings. The effects of oxalic acid, citric acid and succinic acid on dehydrogenase activity in dark brown forest soils under nutrient deficiency were studied systematical y by adding different concentrations of organic acid solutions. [Result] Under nutrient deficiency, dehydrogenase activity in dark brown forest soils was reduced significantly, and the reduction increased with the extension of stress duration. Most organic acid treatments improved dehydrogenase activity in nutrient-deficient dark brown forest soils, and the effects varied with different treatment du-ration and types and concentrations of organic acids. Furthermore, 10.0, 5.0 and 10.0 mmol/L organic acid treatments exhibited the most significant effects on day 10, 20 and 30, respectively. The increment of dehydrogenase activity in different durations showed a downward trend of 30 d〉20 d〉10 d; the improvement effects of three organic acids on dehydrogenase activity showed a downward trend of succinic acid〉 citric acid〉oxalic acid. [Conclusion] Exogenous organic acids improved signifi-cantly dehydrogenase activity in dark brown forest soils under nutrient deficiency and also improved the microbial activity and soil fertility to a certain extent.

Effects of Exogenous Organic Acids on Phosphorus Availability of Dark Brown Forest Soils and Phosphorus Absorption and Accumulation of Larix olgensis Seedlings with Nutrient Deficiency

Different proportions of A1 and B horizons dark brown forest soils （A1∶B=1∶2） were utilized to set the soil nutrient deficient conditions, and Larix olgensis seedlings were cultivated. By simulating organic acids concentrations in forest litter leachates of northeast China, the effects and mechanism of different concentrations of organic acid solutions on phosphorus （P） availability of dark brown forest soils and P absorption of Larix olgensis seedlings with nutrient deficiency were studied. The results showed that, compared with A1 horizon soils, available P contents of mixed soils in A1 and B horizons decreased, and P accumulation and efficiency of P uptake in root and leaves of Larix olgensis seedlings also decreased, but efficiency of P utilization increased. After treatments of exogenous organic acids, available P contents of mixed soils increased and the impact sequence of different organic acids were succinic acid 〉 citric acid 〉 oxalic acid; the concentration of 5.0 mmol/L had the best function, and the best effect of organic acids was at 20 d. Organic acids also increased P accumulation and efficiency of P uptake in roots and leaves of Larix olgensis seedlings, but decreased efficiency of P utilization. The impact strength of organic acids on P accumulation and efficiency of P uptake varied with treatment time, type and concentration of organic acids. The results of 20 d and 30 d in roots were higher than those of 10 d, however, the results of 10 d and 20 d in leaves were higher than those of 30 d, thus, at the earlier stage of organic acids treatments, more P absorbed were transferred to leaves, and at the later stage, more P would be accumulated in roots. The concentration of 10.0 mmol/L had the best function, and the impact sequence of different organic acids was succinic acid 〉 citric acid 〉 oxalic acid. Therefore, organic acids might contribute to P absorption and accumulation by Larix olgensis seedlings, final y increasing the adaptability and endurance of Larix olgensis seedlings to nutrient deficient soils.

Dynamic Analysis on Organic Matter and Nitrogen Pollution of Dongchang Lake

The aim was to explore dynamic changes of organic matter and nitrogen pol ution in Dongchang Lake. [Method] Monitoring data, including BOD5, CODCr, NH3-N and TN, of Dongchang Lake were chosen for analysis during 2002-2011. [Result] Water quality of the six lake districts showed deteriorating in monitor-ing period, and TN was the dominant pol ution factor; BOD5/CODCr ratio was low, suggesting biodegradability of organic pol utant in the lake was lower. NH3/TN ratio was higher, indicating NH3-N was a major factor causing nitrogen exceeding in 2010. In addition, correlations between BOD5 and CODCr and between NH3-N and TN in the lake districts maintained at a significant level. [Conclusion] The research provides references for improving water in Dongchang Lake.

Metagenomic analysis revealing the metabolic role of microbial communities in the free amino acid biosynthesis of Monascus rice vinegar during fermentation

Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains unclear.Through metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar fermentation.Taxonomic profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism pathways.The metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was illuminated.The results revealed that 5 functional genera were closely involved in FAA biosynthesis.This study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.

Soybean(Glycine max)rhizosphere organic phosphorus recycling relies on acid phosphatase activity and specific phosphorusmineralizing-related bacteria in phosphate deficient acidic soils

Bacteria play critical roles in regulating soil phosphorus(P) cycling. The effects of interactions between crops and soil P-availability on bacterial communities and the feedback regulation of soil P cycling by the bacterial community modifications are poorly understood. Here, six soybean(Glycine max) genotypes with differences in P efficiency were cultivated in acidic soils with long-term sufficient or deficient P-fertilizer treatments. The acid phosphatase(AcP) activities, organic-P concentrations and associated bacterial community compositions were determined in bulk and rhizosphere soils. The results showed that both soybean plant P content and the soil AcP activity were negatively correlated with soil organic-P concentration in P-deficient acidic soils. Soil P-availability affected the ɑ-diversity of bacteria in both bulk and rhizosphere soils. However, soybean had a stronger effect on the bacterial community composition, as reflected by the similar biomarker bacteria in the rhizosphere soils in both P-treatments. The relative abundance of biomarker bacteria Proteobacteria was strongly correlated with soil organic-P concentration and AcP activity in low-P treatments. Further high-throughput sequencing of the phoC gene revealed an obvious shift in Proteobacteria groups between bulk soils and rhizosphere soils, which was emphasized by the higher relative abundances of Cupriavidus and Klebsiella, and lower relative abundance of Xanthomonas in rhizosphere soils. Among them, Cupriavidus was the dominant phoC bacterial genus, and it was negatively correlated with the soil organic-P concentration. These findings suggest that soybean growth relies on organic-P mineralization in P-deficient acidic soils, which might be partially achieved by recruiting specific phoCharboring bacteria, such as Cupriavidus.

Application of organic fertilizer for improving soybean production under acidic stress

The presence of acidic soil in rural areas poses difficulties for agricultural production.One factor regulating soil pH is the overuse of inorganic fertilizer.The increased use of fertilizers in soybean production not only raises sustainability concerns but also contributes to soil acidity.Therefore,the use of organic fertilizer could offer a solution for addressing both issues related to soil acidity and sustainability.The purpose of this study was to investigate the manipulation of soil pH using organic fertilizer for soybean production under acidic stress.The planting medium,consisting of a mixture of topsoil,rice husk charcoal,and organic fertilizer(in a ratio of 2:1:1),was supplemented with 0.5 g of NPK fertilizer as a basal treatment in each planting medium.To regulate the soil acidity to pH 4,we added FeSO_(4) and allowed the mixture to incubate for 30 days.The results demonstrate that the application of three types of organic fertilizers chicken manure(P1),oil palm empty bunch fertilizer(P2),and vermicompost(P3)positively impacts the growth of three soybean varieties.The findings indicate that the application of P2 organic fertilizer can increase vegetative growth almost 50%in soybeans on acidic soil,including plant height,leaf count,and root length.Meanwhile,applying P3 organic fertilizer can boost reproductive growth responses in soybeans on acidic soil,such as pod number(from around 0-4 unit to 42-51 unit),grain number(from around 0-5 unit to 88-90 unit),and grain weight(from around 0-0.37 g to 12-25 g).Organic fertilizer has the potential to regulate soil pH,promoting higher yields of soybeans under acidic stress.

Diagnostic efficacy of virtual organ computer-assisted analysis in measuring the volume ratio of subchorionic hematoma with serum progesterone

BACKGROUND Subchorionic hematoma(SCH)is a common complication in early pregnancy characterized by the accumulation of blood between the uterine wall and the chorionic membrane.SCH can lead to adverse pregnancy outcomes such as miscarriage,preterm birth,and other complications.Early detection and accurate assessment of SCH are crucial for appropriate management and improved pregnancy outcomes.AIM To evaluate the diagnostic efficacy of virtual organ computer-assisted analysis(VOCAL)in measuring the volume ratio of SCH to gestational sac(GS)combined with serum progesterone on early pregnancy outcomes in patients with SCH.METHODS A total of 153 patients with SCH in their first-trimester pregnancies between 6 and 11 wk were enrolled.All patients were followed up until a gestational age of 20 wk.The parameters of transvaginal two-dimensional ultrasound,including the circumference of SCH(Cs),surface area of SCH(Ss),circumference of GS(Cg),and surface area of GS(Sg),and the parameters of VOCAL with transvaginal three-dimensional ultrasound,including the three-dimensional volume of SCH(3DVs)and GS(3DVg),were recorded.The size of the SCH and its ratio to the GS size(Cs/Cg,Ss/Sg,3DVs/3DVg)were recorded and compared.RESULTS Compared with those in the normal pregnancy group,the adverse pregnancy group had higher Cs/Cg,Ss/Sg,and 3DVs/3DVg ratios(P<0.05).When 3DVs/3DVg was 0.220,the highest predictive performance predicted adverse pregnancy outcomes,resulting in an AUC of 0.767,and the sensitivity,specificity were 70.2%,75%respectively.VOCAL measuring 3DVs/3DVg combined with serum progesterone gave a diagnostic AUC of 0.824 for early pregnancy outcome in SCH patients,with a high sensitivity of 82.1%and a specificity of 72.1%,which showed a significant difference between AUC.CONCLUSION VOCAL-measured 3DVs/3DVg effectively quantifies the severity of SCH,while combined serum progesterone better predicts adverse pregnancy outcomes.

Ability of Agrogyron elongatum to accumulate the single metal of cadmium, copper, nickel and lead and root exudation of organic acids

Agrogyron elongatum were grown in nutrient solution containing moderate to high amounts of separate heavy metal of Cd, Cu, Ni and Ph in a greenhouse for a 9 - day. Cd, Cu, Ni and Ph generally led to decrease in the elongation of roots although the length of seedlings exposed to Cd and Ph at 0.05 and 0.5 mg/L showed to be slightly greater than that of controls. Of the four metals in the experiment, Ph was absorbed and accumulated to the highest level, with the concentrations of 92754 mg/kg dry weight (DW) in roots and 11683 mg/kg DW in shoots. Cd was moderately accumulated in Agrogyron elongatum, but the maximum bioaccumulation coefficients (BCs) for roots and shoots were observed. The patterns for Cu and Ni uptake and distribution in plants differed from those of Ph and Cd, as it was showed that the shoot accumulation of Cu and Ni was significantly higher than in roots. A. elongation had the highest Ni concentration in shoots (30261 mg/kg DW) at the external concentration of 250 mg/L. Cu ranked second, with a shoot concentration of 12230 mg/kg DW when 50 mg/L Cu in solution was applied. For the four trace elements tested, the highest concentrations in shoots decreased by the order of Ni > Cu > Ph > Cd (mg/kg DW), and those in roots were Ph > Cd > Ni > Cu (mg/kg DW). Malic, oxalic and citric acids exuded by roots exposed to 1 and 50 mg/L of the metals were detected. Release of organic acids from plants significantly differed among the metal treatments. Cu was most effectively in inducing root exudation of the three types of organic acids. Cd, and Ni were also the inducers of secretion of malic and oxalic acids. With reference of Pb, a small amounts of malic and oxalic acids were detected in the root exudates, but few quantities, of citric acid were. found. However, no correlation between alternations in root exudation of organic acids and metal accumulation could be established.

A review of the effects of dietary organic acids fed to swine

Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters （AGP） has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. Numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are （3-4 weeks age） exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coil These acids are the intermediary products in Kreb＇s cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth performance. It is concluded that organic acids and their salts increase the protein utilization especially in weaner pigs and improves production indices.

ATR-FTIR and XPS study on the structure of complexes formed upon the adsorption of simple organic acids on aluminum hydroxide

Information on the binding of organic ligands to metal （hydr）oxide surfaces is useful for understanding the adsorption behaviour of natural organic matter on metal （hydr）oxide. In this study, benzoate and salicylate were employed as the model organic ligands and aluminum hydroxide as the metal hydroxide. The attenuated total reflectance Fourier transform infrared （ATR-FTIR） spectra revealed that the ligands benzoate and salicylate do coordinate directly with the surface of hydrous aluminum hydroxide, thereby forming innersphere surface complexes. It is concluded that when the initial pH is acidic or neutral, monodentate and bridging complexes are to be formed between benzoate and aluminum hydroxide while bridging complexes predominate when the initial pH is alkalic. Monodentate and bridging complexes can be formed at pH 5 while precipitate and bridging complexes are formed at pH 7 when salicylate anions are adsorbed on aluminum hydroxide. The X-ray photoelectron （XP） spectra demonstrated the variation of C 1 s binding energy in the salicyate and phenolic groups before and after adsorption. It implied that the benzoate ligands are adsorbed through the complexation between carboxylate moieties and the aluminum hydroxide surface, while both carboxylate group and phenolic group are involved in the complexation reaction when salicylate is adsorbed onto aluminum hydroxide. The information offered by the XPS confirmed the findings obtained with ATR-FTIR.

Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids

Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the p K _a values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was not correlated with p K _a. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

Cd uptake in rice cultivars treated with organic acids and EDTA

A pot experiment was conducted to examine the activity of antioxidant enzymes, the content of malondialdehyde （MDA）, proline and protein, and Cd uptake in different rice cultivars exposed to Cd （0, 1 and 5 mg/kg） in the presence of organic acids and ethylenediamine tetraacetic acid （EDTA）. The results showed the increase in activity of dismutase （SOD）, contents of proline and protein but a decline in activities of peroxidase （POD） and catalase （CAT）, and MDA content for cultivars Xiushui63 and IIyou527. The resistance to Cd was higher in Xiushui63 than that in IIyou527 under the same Cd treatment. Cadmium contents in grain, straw and roots of both cultivars were markedly reduced in the presence of organic acids and EDTA. Grain Cd contents was the highest for plants treated with organic acids, followed by organic acids ＋ 1/2EDTA, and the lowest with EDTA; Cd contents in straw and root were the lowest for plants treated with organic acids, followed by organic acids ＋ 1/2EDTA, and the highest with EDTA treatment when exposed to Cd.