Arbuscular Mycorrhizal Fungi Contribute to Resistance of Upland Rice to Combined Metal Contamination of Soil

A greenhouse pot experiment was conducted to investigate heavy metal [copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd)] uptake by two upland rice cultivars, ‘91B3’ and ‘277’, grown in a sterilized field soil contaminated by a mixture of Cu, Zn, Pb, and Cd. Rice plants were inoculated with each of three arbuscular mycorrhizal fungi (AMF), Glomus versiforme (GV), Glomus mosseae (GM), and Glomus diaphanum (GD), or remained noninoculated (NM). Both rice cultivars could be colonized by the three AMF used in this experiment. The percentage of mycorrhizal colonization by the three AMFs on the two rice cultivars ranged from 30% to 70%. Mycorrhizal colonization of both upland rice cultivars had a large influence on plant growth by increasing the shoot and root biomass compared with non-inoculated (NM) plants. The results indicate that mycorrhiza exert some protective effects against the combined toxicity of Cu, Zn, Pb, and Cd in the contaminated soil. This conclusion is supported by the partitioning of heavy metals (HMs) in the two cultivars. In the two cultivars, colonization by AMF reduced the translocation of HMs from root to shoot (except that the colonization of AMF increased the Cu translocation of HMs in cultivar ‘277’). Immobilization of the HMs in roots can alleviate the potential toxicity to shoots induced by the mixture of Cu, Zn, Pb, and Cd. The two rice cultivars showed significant differences in uptake of Cu, Zn, Pb, and Cd when uninoculated. GM inoculation gave the most protective effects on the two cultivars under the combined soil contamination.     

锌离子活度对水稻锌积累与分配的影响

采用HEDTA螯合剂缓冲营养液培养法,选用籽粒含锌量有明显差异的2个基因型水稻(BY和Z921),设置4种锌离子活度(pZn2+9.7、10.3、11.0、11.4),研究了锌离子活度对水稻锌积累、分配的影响以及对不同时期水稻叶片中锌的化学形态的影响。结果显示:(1)2个基因型水稻各器官的锌含量都随着锌离子活度的升高而升高,但不同基因型间,同一基因型不同器官间均存在差异,供锌正常的的条件下,锌首先向代谢活性较弱的营养器官分配;缺锌的条件下,锌首先满足籽粒的需要;(2)从籽粒锌分配看,当锌离子活度(pZn2+)小于10.3时,糙米锌含量最高,当pZn2+升高到9.7时,颖壳锌含量则超过糙米,糙米和精米锌含量的比值在0.79～0.90之间,并以pZn2+为9.7时为最小;(3)任一锌离子活度下,BY籽粒锌含量均大于Z921。表明通过筛选籽粒富锌水稻品种来提高稻米锌含量是经济可行的,且通过增加环境锌离子活度来改善水稻的锌营养能显著提高水稻籽粒的锌含量;(4)营养生长前期,水稻叶片中的锌主要以活性较低的醋酸提取态(重金属磷酸盐)存在;营养生长后期,锌主要以乙醇提取态(醇溶性蛋白、氨基酸等)存在。     

Effects of Long‐Term Irrigation using Industrial Wastewater on Soil Properties and Elemental Contents of Rice,Spinach, Clover,and Grass

Abstract

Application of industrial wastewater on agricultural lands increased the amounts of elements in soil and plants. To investigate the effects of wastewater on soil properties and element content in soil and plants, wastewaters of three industries (chrome chemical, wood and paper, and textiles) were examined in 2005. At harvest time, the soil samples were taken from depths of 0–15 and 15–30 cm, and the roots and shoots of rice, spinach, clover, and grass and grain of rice in an industrial wastewater–treated area and untreated area were sampled. Results indicated that the concentrations of zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) increased in river water when wastewater was discharged into it. Use of the river water, influenced by industrial wastewater, for irrigation of rice and other plants increased the amounts of organic matter and available Zn, Cu, Mn, and Fe in soil. Cation exchange capacity was correlated with available Cu and Fe in soil (+0.431** and +0.499**, respectively). Soil organic matter was correlated with available Zn, Cu, Mn, and Fe in soil. However, the clay content in soil did not correlate with these elements. Meanwhile, in roots, shoots, and grains of rice and roots and shoots of spinach, clover, and grasses of agricultural land influenced by industrial wastewater, the amounts of Zn, Cu, Mn, and Fe increased. Therefore, by increasing the amount of Mn in the soil, the concentration of Zn in rice grain decreased and the concentration of Cu and Mn increased. Transferred Zn concentrations to rice grain and shoots of spinach, clover, and grass were more than Cu and Mn and increased in rice grain.     

Study the Effects of Siderophore-Producing Bacteria on Zinc and Phosphorous Nutrition of Canola and Maize Plants

Plant growth-promoting rhizobacteria (PGPR) are soil bacteria that are able to colonize rhizosphere and to enhance plant growth by means of a wide variety of mechanisms. In the present study, Myristica yunnanensis and Stenotrophomonas chelatiphaga strains were recognized as new records in Iran flora. According to the results, these strains significantly affected plants’ zinc and phosphorous contents which could be due to the production of phytosiderophore. Siderophore-producing bacteria increased canola zinc (Zn) content as strategy-I plant, while in maize, it can be said that probably the effect of phytosiderophore produced by plant on increasing root and shoot Zn content was more than siderophore produced by bacteria. These isolates could be used as bio-input for improving the plant productivity as a substitute to chemical fertilizers and also to correct the nutrient deficiencies in canola and maize for sustainable agriculture.     

Genotypic Differences in Selenium Accumulation in Rice Seedlings at Early Growth Stage and Analysis of Dominant Factors Influencing Selenium Content in Rice Seeds

The paper deals with the selenium (Se) accumulation of different genotypes of rice (Oryza sativa Japonica) seedlings at early growth stage and its correlation with the Se content in grains in 151 rice varieties. A field trial showed the Se content in brown rice to range from 29 μg/kg to 103 μg/kg. The results from hydroponic culture with representative varieties of high-, moderate- and low-Se content showed that total Se values for the high-Se genotypes were markedly higher than those of the low-Se varieties. This was true of Se content of the whole plant, Se content of shoots, biomass of shoots, and rate of Se accumulation in shoots. There were, however, no significant differences in values for total Se in roots, rate of accumulation in roots, and biomass of roots between high- and low-Se groups. Selenium content in brown rice was positively correlated with the total Se of the whole plant, shoot, and biomass of shoots. We concluded that the total Se transported from roots to shoots was more important than other factors in Se accumulation and content in brown rice.     

Tolerance of rice plants to trace metals

Abstract

The tolerance of rice (Oryza sativa L. C.V. Earlirose) to various trace metal excesses was tested to determine if high levels of the trace metals found in some field‐grown plants were at toxicity levels. In one experiment, levels of 2200 μg Zn/g dry weight, 44 μg Cu/g dry weight, 4400 μg Mn/g dry weight, and 32 μg Pb/g dry weight in shoots of young plants had no adverse effects on vegetative yields. A level of 3160μgZn/ g dry weight decreased yields about 40% (P = . 05). In another test 51 μg Cu/g dry weight or 94 μg Pb/g dry weight did not decrease vegetative yields. Boron supplied at 10^‐3 MH₃BO₃ not only caused no toxicity but resulted in only 144 μg B/g dry weight in shoots. Root levels of Zn were about equal to those in shoots; Mn levels were lower in roots than in shoots (1/4 to 1/10); B levels were generally low in both shoots and roots with roots 1/10 that of shoots; Cu levels were higher in roots than in shoots. Rice was tolerant of a high level of Cr. The tolerance of rice to high levels of some trace metals in these experiments may be related to high P levels in plants.     

水稻对~(65)Zn吸收和分配的比较研究

本试验以籽粒高锌含量基因型水稻V5 6和低锌含量基因型水稻湘早籼 1 7为材料 ,运用溶液培养和同位素示踪技术 ,探讨了水稻不同时期对65Zn吸收、运转和分配 ,特别是往籽粒的运输与分配。试验结果表明 :V5 6苗期根系吸收65Zn的能力和往地上部运转65Zn的能力强 ,累积的65Zn较少 ;生殖阶段分配到剑叶的65Zn低 ,籽粒的65Zn分配率高 ,籽粒65Zn累积高。湘早籼 1 7的结果恰恰相反     

Effect of different foliar zinc application at different growth stages on seed zinc concentration and its impact on seedling vigor in rice

This study evaluated how zinc (Zn) concentration of rice (Oryza sativa L.) seed may be increased and subsequent seedling growth improved by foliar Zn application. Eight foliar Zn treatments of 0.5% zinc sulfate (ZnSO₄?·?7H₂O) were applied to the rice plant at different growth stages. The resulting seeds were germinated to evaluate effects of seed Zn on seedling growth. Foliar Zn increased paddy Zn concentration only when applied after flowering, with larger increases when applications were repeated. The largest increases of up to ten-fold were in the husk, and smaller increases in brown rice Zn. In the first few days of germination, seedlings from seeds with 42 to 67?mg Zn?kg^?1 had longer roots and coleoptiles than those from seeds with 18?mg Zn?kg^?1, but this effect disappeared later. The benefit of high seed Zn in seedling growth is also indicated by a positive correlation between Zn concentration in germinating seeds and the combined roots and shoot dry weight (r?=?0.55, p?相似文献   

Zinc alleviates growth inhibition and oxidative stress caused by cadmium in rice

A hydroponic experiment with two rice cultivars differing in cadmium (Cd) tolerance was conducted to investigate the alleviating effect of zinc (Zn) on growth inhibition and oxidative stress caused by Cd. Treatments consisted of all combinations of two Zn concentrations (0.2 and 1 μM), three Cd concentrations (0, 1, and 5 μM), and two rice cultivars (Bing 97252, Cd‐tolerant; Xiushui 63, Cd‐sensitive). Cd toxicity caused a dramatic reduction in plant height and biomass, chlorophyll concentration and photosynthetic rate, and an increase in Cd concentration in both roots and shoots, malondialdehyde (MDA) concentration, and superoxide dismutase (SOD) and peroxidase (POD) activities in shoots. The response of all these parameters was much larger for Xiushui 63 than for Bing 97252. Addition of Zn to the medium solution alleviated Cd toxicity, which was reflected in a significant increase in plant height, biomass, chlorophyll concentration, and photosynthetic rate, and a marked decrease in MDA concentration and activity of anti‐oxidative enzymes. However, it was noted that Zn increased shoot Cd concentration at higher Cd supply, probably due to the enhancement of Cd translocation from roots to shoots. Therefore, further studies are necessary to determine the effect of Zn supply on Cd translocation from vegetative organs to grains or grain Cd accumulation before Zn fertilizer is applied to Cd‐contaminated soils to alleviate Cd toxicity in rice.     

Irrigation and Zn fertilizer management improves Zn phyto‐availability in various rice production systems

Zinc (Zn) is an important micronutrient for rice (Oryza sativa L.) production and its deficiency has been observed in various production systems. High grain Zn concentration is equally important for high rice yield and human health. In this work, the effects of Zn fertilization on seedling growth, grain yield, grain Zn concentration, and their association with root traits were studied under alternate wetting and drying (AWD), aerobic rice (AR), system of rice intensification (SRI), and continuous flooding (CF). Zinc fertilization (15 kg ha^?1) improved nursery seedlings chlorophyll and Zn concentrations, root length, and number of roots with highest values observed in CF. At harvesting, maximum plant height, panicle length, total and panicle bearing tillers, and kernel yield were found with Zn addition in AWD and CF rice systems. Mid season drainage provided at maximum tillering and Zn fertilization increased its concentration in leaves, culms, panicles, and grains under CF and AR at physiological maturity. Most of Zn applied was allocated into culms and panicles, nevertheless, a significant increase in grain Zn concentration was also observed in all production systems. Association of leaf Zn with grain Zn concentration was stronger than with culm and panicle Zn. The results indicate that Zn application after rice nursery transplanting is more important for grain Zn enrichment in all rice systems than for increase in grain yield in all systems except AWD where grain yield was also increased. More grain yield in CF and AWD as compared to SRI and AR can also be attributed to decreased spikelet sterility and to better Zn phyto‐availability in these rice systems at physiological maturity.     

Micronutrient enrichment mediated by plant-microbe interactions and rice cultivation practices

A field experiment was conducted to evaluate the effect of different plant growth promoting microorganisms (PGPM) on micronutrient enrichment of rice crops grown under conventional (flooded) and SRI (System of Rice Intensification) practices. Significant differences were recorded among treatments and cultivation practices in terms of soil microbial activity reflected in enhanced nutrient uptake, enzyme activity, and yield. The Anabaena-based biofilm inoculants were particularly superior under both methods of cultivation, leading to 13–46% enhancement of iron and 15-41% enhancement of zinc in rice grains over uninoculated controls. SRI was found to be superior in terms of enhancing the concentration of zinc, copper, iron, and manganese (Zn, Cu, Fe and Mn), particularly in grains, and significant in increasing the activity of defense- and pathogenesis- related enzymes and yield parameters. This study illustrates the utility of cyanobacteria-based inoculants for both methods of rice cultivation and their significant interactions with the plant, leading to micronutrient enrichment of rice grains. Such formulations can complement the current biofortification strategies and help in combating the problems of malnutrition globally.     

Low efficiency of Zn uptake and translocation in plants provide poor micronutrient enrichment in rice and soybean grains

Abstract

Recent research has shown the need for an in-depth knowledge of zinc biofortification of cereal and oilseed grains due to its importance to human nutrition. However, little is known about the Zn dynamics in plant–soil system. In this work, we evaluated the effect of soil-applied Zn on the absorption, translocation, and compartmentalization of Zn in rice (Oryza sativa L.) and soybean (Glycine max L. Merrill) plants. The soil used in the greenhouse experiment was fertilized with zinc chloride (ZnCl₂) at rates of 0, 1, 2, 4, and 8?mg Zn kg^?1. The source of Zn was labeled by ⁶⁵Zn with specific activity of 185.5 kBq mg^?1 Zn. The amount of Zn derived from fertilizer and its use in each plants compartment was determined by direct method in isotopic calculations. Rice and soybean plants presented low efficiency in the absorption from soil-applied Zn. The accumulated Zn in the panicle, pod, and grains was not modified, due to its low translocation in the plant. The Zn uptake in rice plants was from 1.34 to 4.60?mg pot^?1 in shoots and just 0.81 to 1.43?mg pot^?1 translocated to panicles. Soybean plants presented Zn uptake between 2.36 and 4.68?mg pot^?1 in shoots, out of which 0.19 to 0.34?mg.pot^?1 and 0.48 to 0.57?mg pot^?1 translocated to grains and pods, respectively. The nutrient utilization from fertilizer was low, with mean values of 12 and 8.7% for rice and soybean plants, respectively. Soil-applied Zn showed low capacity for enriching rice panicle and soybean pod or grain probably due low Zn uptake and translocation.     

土壤中Cd、P、Zn含量对水稻产量和植株中矿物浓度的影响

在温室中进行了剖析添加的Cd、P、Zn对稻谷产量、植株和稻草中的矿物含量以及糙米中Cd的浓度的研究。P增加了稻谷和植株产量,而Cd、Zn和P-Zn的交互作用使其降低。稻谷和植株产量有类似的线性回归方程式,其稻谷的线性回归方程为: Y=17.24+0.0466(P)-0.1850(Cd)-0.1115(Zn)-0.0005(P-Zn) 其R²=0.97^**,式中Y为稻谷产量(克/株);P为添加的P浓度(毫克/公斤);(Cd)为添加的Cd浓度(毫克/公斤);(Zn)为添加的Zn浓度(毫克/公斤);(P-Zn)为P和Zn的交互作用。所有处理均明显地影响着稻草中矿物元素的含量。粕米中的Cd浓度随着添加的Cd、P、Zn浓度的增加而增加;但多元回归分析表明只有Cd的影响是显著的。粕米中Cd的浓度与收获时用0.05M HCI所提取的风干土中的Cd浓度有极显著相关性(Y=0.75^**).对糙米中Cd浓度的评价进行了简要的讨论。     

不同供锌水平对苹果幼树干物质和锌积累及分配的影响

采用盆栽砂培试验,研究了低、中、高3个供锌水平(Zn 0.013、0.254和5.070 mg/L)对苹果幼树干物质和锌积累、分配动态的影响。结果表明,锌的过量及缺乏均对果树的生长及养分吸收产生影响。生长初期,苹果幼树根系活动较晚,枝叶的快速生长主要利用根茎中的养分,锌的积累量呈快速增加趋势,处理间差异显著;低锌处理,除根系明显增加外,其他器官变化较小,根系的锌分配比例明显高于中锌、高锌处理。说明生长后期,低锌、高锌抑制了树体的生长,且低锌处理的树体锌主要分布于地下,上运明显受阻;而中锌、高锌处理,地上部锌含量要高于根系。     

不同pH和供Zn条件下HCO_3~-对冬小麦幼苗生长和锌营养的影响

采用营养液培养法,研究了不同pH和供Zn条件下高浓度HCO3-(10 mmol L-1)对小麦幼苗生长,尤其是对锌营养的影响,结果表明:当营养液起始pH为6时,HCO3-在缺Zn时对小麦根系生长的抑制作用较为明显,而正常供Zn时的影响较小。当营养液起始pH为8时,不论缺Zn还是供Zn,添加HCO3-对根系和地上部均未表现出明显的抑制作用。HCO3-在酸性营养液中能极大促进小麦植株根系和地上部尤其是根系对Zn的吸收,而在碱性条件下则抑制小麦幼苗根系和地上部对Zn的吸收。此外,HCO3-能显著抑制Zn从根系向地上部分的转运,从而造成在根系中的大量积累。HCO3-加入营养液后会生成少量的CO32-,并使营养液pH维持在较高水平上。     

硼、锌和铁对龙胆中龙胆苦dan含量和产量的影响

A field experiment of 2-year-old gentian （Gentiana manshurica Kitag.） with application of boron （B）, zinc （Zn）, and iron （Fe） in Taikang County, Heilongjiang Province, was conducted to study the effects of the three microelements on gentiopicroside content in the roots of gentian, uptake of these elements, and root dry weight as well as the ratio of root dry weight to fresh weight. Zinc sulfate, ferrous sulfate, and borax were split sprinkled on 2-year-old gentian on June 26, July 18, and August 25, 2002, with sprinkling water taken as a control. Compared with the control, applying B significantly increased （P 〈 0.05） the gentiopicroside content by 7.9%, and there was a highly significant increase of 22.4% （P 〈 0.01） in the root dry weight. Meanwhile, B content in the shoots of gentian gradually increased from the vegetative to the harvesting period, while Fe decreased at first and then increased. Fc treatment increased the gentiopicroside content only by 4.0% and the content was slightly decreased by the Zn treatment （3.1%） as compared to the control. The three microelements had different effects on the gentiopicroside content and appropriate microelement application could increase active ingredient content of gentian.     

锌铬复合污染对水稻根系氮代谢的影响

通过盆栽试验,研究了锌铬复合污染对水稻(Oryza sativaL.)根系氮代谢的影响。结果表明,在锌铬复合污染下,随着重金属浓度的增加,水稻在不同生育期的生物量均降低,根冠比均有增加的趋势。在水稻不同生育期,水稻根系全氮含量及可溶性蛋白含量随铬浓度的变化规律不明显,而随锌浓度的变化规律较为明显,即随锌浓度的增加呈增大的趋势。偏相关分析表明,在水稻不同生育期,土壤中锌浓度、铬浓度与水稻根系全氮未产生复合效应,与可溶性蛋白含量在水稻分蘖期产生了Zn-Cr协同效应。这可能与在水稻不同生育期,其根系对重金属胁迫的适应程度不同有关。     

Effects of Green Manures and Zinc Fertilizer Sources on DTPA-Extractable Zinc in Soil and Zinc Content in Basmati Rice Plants at Different Growth Stages

Rice is very sensitive to low zinc(Zn) supply in submerged paddy soils and Zn deficiency is one of the major limiting factors in determining rice production in India. A field experiment was conducted during the summer-rainy seasons of 2009 and 2010 at the research farm of the Indian Agricultural Research Institute, New Delhi, to determine the effects of summer green manure crops and Zn fertilizers on diethylenetriaminepentaacetic acid(DTPA)-extractable(available) Zn concentration in soil and total Zn content in Basmati rice cultivar Pusa Basmati 1 at periodic intervals. Summer green manure crops included Sesbania aculeata(Dhaincha),Crotalaria juncea(Sunhemp), and Vigna unguiculata(Cowpea) and the Zn fertilizers used were ethylenediaminetetraacetic acid(EDTA)-chelated Zn, ZnSO_4·7H_2O, ZnSO_4·H_2O, ZnO, and ZnSO_4·7H_2O + ZnO. Beneficial effects of summer green manure crops and Zn fertilizers on DTPA-extractable Zn concentration in soil and total Zn content in dry matter of Basmati rice at periodic intervals were observed, with significant increases in all the determined parameters, in comparison with those in the control(no Zn application or summer fallow). The rate of increase varied among summer green manure crops and Zn fertilizers during both years. Among the summer green manures, incorporation of S. aculeata led to a significant increase in mean Zn content in Basmati rice grain and straw when compared with C. juncea, V. unguiculata, and summer fallow treatments. Among the Zn fertilizers, significant increases in Zn content in Basmati rice dry matter and DTPA-extractable Zn concentration in soil during various growth stages of the plant were recorded with EDTA-chelated Zn application, followed by the application of ZnSO_4·7H_2O, ZnSO_4·H_2O, ZnSO_4·7H_2O + ZnO, ZnO,and no Zn. The highest mean Zn content in Basmati rice grain and straw was recorded with EDTA-chelated Zn application in 2009 and 2010, respectively. The application of ZnSO_4·7H_2O was the second best treatment after EDTA-chelated Zn; however, it was statistically inferior to EDTA-chelated Zn. The lowest values were recorded with the control(no Zn application) during both years of study. The amount of Zn concentration in soil was found to be significantly positively correlated with the Zn content in Basmati rice dry matter during both years. Significantly higher levels of residual fertility in soil after the harvest of Basmati rice were observed with application of EDTA-chelated Zn and incorporation of S. aculeata when compared with those of other Zn sources and summer green manures.     

AMF和PGPR修复甲胺磷污染土壤的效应

丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和根围促生细菌(plant growthpromoting rhizobacteria,PGPR)能降解有毒有机物,但分解土壤中残留甲胺磷农药尚未见报道。本试验旨在测定AMF和PGPR矿化甲胺磷的效应。试验设甲胺磷0、50、100和150μg g-1下,对番茄(Lycospersicon esculentum,品种金冠)接种AMF Glomus mosseae(Gm)、Glomus etunicatum(Ge)、PGPR Bacillus subtilis(Bs)、Bacillus sp.B697(Bsp)、Pseudomonas fluorescens(Pf)、Gm+Bs、Gm+Bsp、Gm+Pf、Ge+Bs、Ge+Bsp、Ge+Pf和不接种对照,共48个处理。结果表明,接种Gm显著增加了根区土壤和根内PGPR定殖数量,而Pf处理显著提高了AMF侵染率,表明Gm与Pf能够相互促进。甲胺磷100μg g-1水平下,Gm+Pf处理的番茄株高显著高于其他处理,地上部干重显著高于其他处理(Ge+Pf除外),根系干重显著高于对照、PGPR各处理和Ge处理;而根内甲胺磷浓度则显著低于其他处理,茎叶中的则显著低于其他处理(Gm+Bs、Gm+Bsp和Ge+Pf除外)。AMF、PGPR或AMF+PGPR处理均显著降低番茄体内甲胺磷浓度。甲胺磷50~100μg g-1水平下,Gm+Pf显著降低根区土壤中甲胺磷残留量,矿化率达52%~60.6%。AMF和PGPR显著提高了根区土壤中甲胺脱氢酶活性,其中以Gm+Pf组合处理的酶活性最高。表明AMF和PGPR均能促进土壤中残留甲胺磷的降解,Gm+Pf是本试验条件下的最佳组合。     

Effects of arbuscular mycorrhizal fungi on the growth and zinc uptake of trifoliate orange (Poncirus trifoliata) seedlings grown in low-zinc soil

The effects of the arbuscular mycorrhizal (AM) fungi, Glomus intraradices and G. versiforme, on growth and zinc (Zn) uptake were investigated in trifoliate orange (Poncirus trifoliata) seedlings exposed to low-Zn soil. Low-Zn decreased growth, levels of leaf chlorophyll, soluble protein and sugar, and soil enzymatic activities, and pH in 0–2 cm rhizosphere soil. Low-Zn soil also decreased mineral nutrients (including Zn) concentrations in the shoots and roots. Glomus intraradices especially, significantly enhanced plant biomass, leaf soluble protein and sugar concentrations, root viability, acid phosphatase, catalase, invertase and urease activities, and easily extractable glomalin content in 0–2 cm and 2–4 cm rhizosphere soil. It also increased concentrations of Zn, phosphorus, potassium and magnesium in the shoots and roots, while decreased the soil pH. Arbuscular mycorrhizal fungi, especially G. intraradices, has the potential to improve growth and Zn uptake of triofoliate orange seedlings grown in low-Zn soil.