铁和不同形态氮素对玉米植株吸收矿质元素及其在体内分布的影响 Ⅱ.对铁、锰、铜、锌等营养元素的影响

用营养液培养方法研究了铁和两种形态氮素对玉米植株吸收铁、锰、铜、锌等微量元素及其在体内分布的影响。结果表明:与硝态氮(NO3--N)相比,铵态氮(NH4+-N)显著提高了玉米对铁的吸收,降低了对锰、铜及锌的吸收。供铁也明显提高了植株地上部铁的吸收总量,降低了锰及锌的吸收量,尤其是在供应No3--N时这种作用更为明显。在缺铁条件下,NH4+-N处理的玉米新叶中铁的含量明显高于NO3--N处理;而新叶、老叶、茎中锰、锌、铜含量以及根中锰、锌含量都明显低于NO3--N处理。但使用NH4+-N时,根中铜的含量较高。在供铁条件下,NH4+-N处理的玉米植株四个不同器官中锰和锌的含量显著低于NO3--N处理的植株,而铜的含量正好相反。在缺铁条件下,玉米新叶中活性锰、活性锌的含量显著高于供铁处理;与NO3--N相比,NH4+-N的供应也显著降低了玉米新叶中活性锰以及活性锌的含量。     

过量表达pAPX基因提高水稻对镉胁迫的耐性

研究了编码大麦pAPX的基因HvAPXI导入水稻并过量表达后，转pAPX水稻在镉胁迫下的生长状况、生理指标及镉含量。结果发现，由于pAPX基因的过量表达，转基因植株的根系伸长量、生物量、叶绿素含量以及APX活性都明显高于野生型植株。与野生型植株相比，转基因水稻对镉胁迫具有明显的耐性。伴随对镉胁迫耐性的提高，转pAPX水稻对镉的累积量也同时提高。     

旱改水对水稻幼苗生长的影响及秸秆的改良作用

本研究以江汉平原旱改水为研究背景,采用土壤盆栽试验和室内淹水培养相结合的方法,以多年水稻土为对照,研究了多年棉田土旱改水及添加秸秆(9 g·kg-1)对水稻幼苗生长和矿质元素吸收的影响以及土壤氧化还原电位和有效态铁、锰、铜、锌含量变化,为旱改水水稻的种植提供参考。结果表明,棉田土旱改水后,水稻幼苗生长缓慢并出现失绿黄化症状,其地上部干重和叶绿素含量仅分别约为水稻土处理的30%和20%。旱改水处理水稻植株Fe含量显著低于、而Cu和Zn含量则显著高于水稻土处理。棉田土旱改水土壤氧化还原电位(Eh)显著高于水稻土;淹水处理10 d,土壤DTPA-Fe含量仅为水稻土的7%左右,而DTPA-Cu和DTPA-Zn含量则分别是水稻土的1.4~2.5倍和1.6~1.8倍。随着淹水时间的延长,棉田土旱改水土壤有效态铁含量逐渐增加,有效态锰、铜和锌含量呈先升高后降低趋势;到淹水处理的第28 d,棉田土旱改水土壤有效态铁、锰、铜和锌含量与水稻土之间的差异逐渐缩小。Fe不足及Cu过量可能是导致旱改水水稻幼苗生长缓慢、失绿黄化的主要原因。旱改水条件下添加秸秆可以降低土壤的Eh值,提高土壤DTPA-Fe含量及降低土壤DTPA-Cu和DTPA-Zn含量,显著提高旱改水初期水稻幼苗叶绿素含量,但对水稻生物量无显著影响。添加秸秆并不能完全消除旱改水对水稻幼苗生长的抑制作用。     

缺磷对不同作物根系形态及体内养分含量浓度的影响

采用营养液培养方法,以水稻、 小麦、 玉米和大豆为试验材料,研究了短期缺磷（2周）诱导根表沉积铁氧化物是否为水稻特有的性质,以及缺磷对不同作物根系形态及其吸收钾、 钙、 铁、 锰、 铜、 锌营养元素的影响。结果表明,供磷和缺磷处理并没有影响小麦、 玉米和大豆3种作物根系的颜色,而缺磷处理水稻根表沉积了铁氧化物而呈红（黄）棕色,且铁氧化物不均匀地富集在根细胞壁的孔隙中; 缺磷促进了水稻,小麦,玉米和大豆根系的生长,分别比供磷处理伸长了11%、 11%、 20%和11%（P0.05）。此外,缺磷胁迫下水稻根表铁氧化物增强了钙、 铁、 锰、 铜和锌在根表的富集而成为其进入根系的缓冲层。缺磷处理水稻根中铁浓度明显高于供磷处理（P0.05）,而地上部铁的浓度仅为磷营养正常水稻植株的18%,这说明缺磷诱导的铁氧化物促进了根系对铁的吸收但抑制了铁由根系向地上部的转运。短期缺磷对其他养分在水稻根中和地上部的浓度没有明显影响。对于其他 3 种作物,短期缺磷没有明显影响钾、 钙、 铁、 锰、 铜和锌在其根表富集及在植物体内的浓度。因此,在供试的4 种作物中,由于磷胁迫诱导根表形成铁氧化物是水稻特有的性质,铁氧化物的沉积可促进铁的吸收但抑制了铁向地上部的转运,而短期缺磷并没有影响其他3种作物对钾、 钙、 铁、 锰、 铜和锌养分的吸收和转运。     

Ri质粒T-DNA对6年生转基因三倍体毛白杨生长和生理性状的影响

为探索外源基因在成年树木中的表达及稳定性,以转Ri质粒6年生三倍体毛白杨成年树木为材料,以同时种植的未转基因三倍体毛白杨为对照植株,对21个转基因株系和对照植株进行外源基因检测和生长、生理特性测定。PCR检测结果证明,Ri质粒T-DNA上的tms、rolC基因在各转基因株系基因组中稳定存在。转基因株系生长受到不同程度影响,各转基因株系的叶柄长、叶片长、叶片宽度和叶面积均小于对照植株,叶片长宽比大于对照植株;71%的转基因株系树高低于对照植株;81%的转基因株系胸径低于对照植株。转基因株系叶绿素a和叶绿素a+b含量、Fv/Fm值、PI值均低于对照植株。81%的转基因株系叶片内源GA3含量及所有株系叶片的内源IAA含量和IAA/ABA比值均高于对照植株,而86%转基因株系叶片的内源ABA含量低于对照植株。T-DNA能够在三倍体毛白杨成年树木中稳定表达,使植物体内内源IAA和GA3含量提高,生长受到抑制,但不同株系存在较大差异。本研究结果为进一步研究外源基因在植物体内的表达调控机制提供了参考依据。     

过量Fe2+对水稻生长和某些生理性状的影响

通过溶液培养研究了不同浓度氧化亚铁 (Fe2+)胁迫对水稻的生长、叶绿素含量及抗氧化酶活性的影响。结果表明 ,高浓度的Fe2+ 胁迫明显抑制水稻地上部和根系的生长、降低下位叶片叶绿素含量。当介质中Fe2+浓度过高时 ,水稻植株体内过氧化物酶 (POD)、过氧化氢酶 (CAT)和硝酸还原酶 (NR)活性明显受抑。然而 ,低浓度Fe2+胁迫时 ,上述酶活性反而提高 ,这可能是水稻抵御亚铁毒害的一种适应性机制。     

长期施用有机肥对紫色水稻土铁锰铜锌形态的影响

以长期定位试验为基本材料 ,研究了 9年连续施用有机肥对紫色水稻土铁、锰、铜、锌形态的影响。结果表明 ,有机肥是土壤铁、锰、铜、锌的良好给源。紫色水稻土长期施用有机肥与单施化肥比较 ,土壤中的全铁、全锰变化不大 ,全锌提高了 5.5%～ 30.0% ,交换态铁、碳酸盐结合态铁、有机态铁、无定形结合态铁分别提高了1.5%～12.7%、2.4%～8.9%、11.6%～19.5%、32.5%～72.5%。锰、锌的各形态数量均有不同程度的增加。同时 ,长期施用有机肥增大了土壤铜的消耗 ,全铜含量有下降的趋势。     

小金海棠Fe3+-还原酶基因MxFRO在酵母中的表达及其活性检测

为研究苹果属植物抗缺铁的分子生物学机理,从铁高效基因型小金海棠（Malus xiaojinensis）中克隆了Fe3+-还原酶基因MxFRO。MxFRO2的cDNA序列长2283bp,开放阅读框为2166bp,编码722个氨基酸。半定量RT-PCR结果表明MxFRO在小金海棠的根和叶中均受缺铁胁迫诱导。 将MxFRO转入野生型酵母中,结果表明转基因酵母的Fe3+-还原酶活性是对照的2.8倍,因此我们初步推测MxFRO基因编码的蛋白具有Fe3+-还原酶活性。     

激光剥蚀–电感耦合等离子体质谱分析缺锌胁迫玉米根尖微量元素空间分布

【目的】激光剥蚀?电感耦合等离子体质谱 (laser ablation inductively coupled plasma mass spectrometry,LA-ICP-MS) 法是一种利用聚焦激光扫描激发固体样品,并经电感耦合等离子体质谱离子化,以分析样品元素含量及分布的新兴技术。本文利用LA-ICP-MS技术研究缺锌 (Zn) 胁迫下玉米根尖铁 (Fe)、锰 (Mn)、铜 (Cu)、Zn元素的分布定位,以期从组织水平揭示作物中Zn的转运富集规律及缺Zn对微量金属元素吸收转运的影响。【方法】以玉米‘郑单958’为试材,用不同加锌浓度营养液进行培养,获得根系样品烘干后磨碎、混匀、压片,取适量混匀的根系样品消煮,利用液体进样系统ICP-MS检测得到样品中实际元素含量,并与样品压片LA-ICP-MS检测信号值间进行线性回归分析,标准曲线相关性良好 (R2 = 0.9995),从而获得可适用于LA-ICP-MS定量分析的自制根系标准样品。将此标准样品与待测根尖样品放入LA样品池中,13C作为内标元素,进行缺锌胁迫下玉米根尖中锌元素分布特征的定量成像研究。【结果】缺锌胁迫下玉米根系锌元素含量显著降低,仅为正常植株的27.78%;缺锌根系中Mn和Cu含量升高。LA-ICP-MS系统定量成像显示,玉米根尖顶端Zn含量较高,由表皮向内锌含量逐渐增加;缺Zn处理根系Zn含量降低,根尖顶端Zn分布明显减少。利用LA-ICP-MS检测信号强度值对Fe、Mn、Cu元素进行定性分布,成像显示在正常根系中Fe、Mn、Cu元素在根尖前端信号强度较高,由表向内逐渐增加;缺锌处理下,根系中Fe、Mn、Cu信号强度均有不同程度增加。【结论】正常施锌玉米根尖中锌、铁、锰、铜分布呈现由表皮向中柱增加的趋势;缺锌胁迫下根系锌含量显著降低,铁、锰、铜均有不同程度积累。     

外源一氧化氮介导铜胁迫下番茄幼苗中铁、锌、锰的累积及亚细胞分布

采用营养液培养方法,以改良毛粉802F1番茄为材料, 研究外源一氧化氮（NO,SNP为供体）对铜（Cu）胁迫下番茄幼苗铁（Fe）、 锌（Zn）、 锰（Mn）吸收分配的影响。结果显示, 50 mol/ L的 Cu2+ 胁迫下,番茄幼苗的生物量和株高显著降低了33.7% 和23.1%,外施100 mol/L SNP可显著缓解这种抑制作用, 提高Cu 胁迫下番茄幼苗根系、 茎中Fe、 Mn含量及叶柄、 叶片中Fe、 Zn含量,降低茎中Zn含量及叶柄、 叶片中Mn含量; 根系、 茎、 叶柄、 叶片Fe、 Zn及根系和茎中Mn的累积相应增加; 根系吸收的Fe、 Zn、 Mn向地上部的转运降低。Cu 胁迫下, 外源NO可显著提高番茄液泡、 细胞器的Fe、 Zn 含量, 降低根系和叶片细胞壁Fe、 Zn、 Mn含量。在作为转运组织的茎和叶柄中,Mn主要分布在细胞壁上,而在叶柄和叶片液泡、 细胞器中也有增加。表明外源NO可以调控番茄幼苗各部位及亚细胞中Fe、 Zn、 Mn的合理分布,维持胞质离子稳态和矿质营养元素平衡,缓解铜胁迫,保证番茄幼苗正常的生理代谢。     

Effects of drought stress on concentration of macro- and micro-nutrients in Castor (Ricinus communis L.) plant

This study evaluated effects of drought stress on the concentrations of mineral elements in the leaves of different ecotypes of castor plant. The experimental design was a split-plot randomized complete block with three replications. It was carried out at Fozveh Agricultural Research Station located 20 km from Esfahan, Iran in 2014. The main plot was four levels of water stress (30%, 45%, 60%, and 75% moisture content) and the sub-plot was six castor plant ecotypes (Esfahan, Ardestan, Arak, Naein, Yazd, and Ahwaz). The potassium (K), magnesium (Mg), calcium (Ca), sodium (Na), iron (Fe), copper (Cu), and zinc (Zn) contents were measured and found to be significantly affected by drought stress. Drought stress increased K, Ca and Na contents and decreased Fe, Cu, Zn, and Mg contents of the plants. Various ecotypes of castor plant showed different reactions to drought stress and the Fe concentration varied significantly by the castor plant ecotypes. Interaction between water stress and ecotypes was significant only for Cu and Zn. Understanding the element concentrations under drought stress can be useful for predicting growth and development of castor plants.     

Effects of chromium stress on the subcellular distribution and chemical form of Ca,Mg, Fe,and Zn in two rice genotypes

A hydroponic experiment was carried out to study effects of chromium (Cr) stress on the subcellular distribution and chemical form of Ca, Mg, Fe, and Zn in two rice genotypes differing in Cr accumulation. The results showed that Ca, Mg, Fe, and Zn ions were mainly located in cell walls and vacuoles in roots. However, large amounts of metal ions were transferred from the vacuole to the nucleus and to other functional organelles in shoots. Chromium concentrations in the nutrient solution of 50 μM and above significantly decreased Ca concentrations in the chloroplast/trophoplast, the nucleus, and in mitochondria. It further increased Mg concentrations in the nucleus and in mitochondria, as well as Zn and Fe concentrations in the chloroplast/trophoplast. These Cr‐induced changes in ion concentrations were associated with a significant reduction in plant biomass. It is suggested that Cr stress interferes with the functions of mineral nutrients in rice plants, thus causing a serious inhibition of plant growth. The chemical forms of the four nutrients were determined by successive extraction. Except for Ca, which was mainly chelated with insoluble phosphate and oxalic acid, Mg, Zn, and Fe were extractable by 80% ethanol, d‐H₂O, and 1μM NaCl. The results indicated that these low–molecular weight compounds, such as organic acids and amino acids, may play an important role in deposition and translocation of Mg, Zn, and Fe in the xylem system of rice plants.     

Comparison of the functions of the barley nicotianamine synthase gene HvNAS1 and rice nicotianamine synthase gene OsNAS1 promoters in response to iron deficiency in transgenic tobacco

Barley ( Hordeum vulgare L.) nicotianamine synthase gene ( HvNAS1 ) expression in barley is strongly induced by Fe deficiency in the roots and rice ( Oryza sativa L.) nicotianamine synthase gene ( OsNAS1 ) expression in rice is induced by Fe deficiency both in the roots and in the shoots. In dicots, NAS genes are not strongly induced by Fe deficiency, and they function to maintain Fe homeostasis. Rice OsNAS1promoter::GUS or barley HvNAS1promoter::GUS was introduced into tobacco ( Nicotiana tabacum L.) and tissue specificities and systemic regulation of their expression were compared. A split-root experiment revealed that the HvNAS1 promoter exhibited functions similar to those of Fe-acquisition-related genes in tobacco roots, suggesting that this promoter responded to certain Fe-deficiency systemic signals and to the Fe concentration in the rhizosphere. The HvNAS1 promoter might harbor a type of universal system of gene expression for Fe acquisition. However, the OsNAS1 promoter did not respond to local application of Fe to the roots and induced GUS activities in mature leaves in response to Fe deficiency. This promoter might possess numerous types of cis -acting sequences that are involved in Fe metabolism.     

Application of High Copper and Zinc Compost and Its Effects on Soil Properties and Growth of Barley

Abstract

A compost of high copper (Cu) and zinc (Zn) content was added to soil, and the growth of barley (Hordeum vulgare L.) was evaluated. Four treatments were established, based on the addition of increasing quantities of compost (0, 2, 5, and 10% w/w). Germination, plant growth, biomass production, and element [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), Cu, manganese (Mn), and Zn] contents of soil and barley were determined following a 16‐week growing period. Following harvesting of the barley, analysis of the different mixtures of soil and compost was performed. Micronutrient contents in soils as affected by compost additions were determined with diethylene–triamine–pentaacetic acid (DTPA) (Cu, Mn, Fe, and Zn) or ammonium acetate [Ca, Na, Mg, K, cation exchange capacity (CEC)] extractions, and soils levels were compared to plant uptake where appropriate. Increasing rates of compost had no affect on Ca, Mg, or K concentration in barley. Levels of Cu, Zn, Mn, and Na, however, increased with compost application. High correlations were found for DTPA‐extractable Cu and Zn with barley head and shoot content and for Mn‐DTPA and shoot Mn content. Ammonium acetate–extractable Na was highly correlated with Na content in the shoot. High levels of electrical conductivity (EC), Cu, Zn, and Na may limit utilization of the compost.     

大气CO2浓度升高对矿质元素在水稻中分配及其根际有效性的影响

在开放式空气CO_2浓度升高(free-air CO_2 enrichment, FACE)条件下,研究了籼稻IIY084与粳稻WYJ23根际土壤矿质元素(Fe、Mn、Cu、Zn、Ca和Mg)有效态含量及其在水稻各组织中的吸收与分配,结合前期稻米矿质元素含量下降的研究结果,探讨了其下降的机制。结果表明:大气CO_2浓度升高,显著增加水稻穗、茎、根和整株生物量,两个品种平均增加19.4%、9.3%、23.4%、16.0%;根际土壤中矿质元素的有效态含量大体呈增加趋势;除Ca吸收量增加外,水稻其他矿质元素总吸收量未发生显著变化;显著促进大部分矿质元素在穗中的吸收与分配,而降低其在茎中的分配比;在穗内有增加大部分矿质元素在壳梗中滞留的趋势,相应地减少其在糙米中的分配比。品种效应分析显示,IIY084的茎和整株生物量,以及穗中Fe、Mn、Cu,叶中Zn、Mg,茎中Cu的吸收量与分配百分数均显著高于WYJ23,而叶中Mn、茎中Fe和根中Cu、Zn则呈相反趋势。可见,大气CO_2浓度升高条件下,碳水化合物与矿质元素从植株营养器官到籽粒的不平衡转运以及在壳梗中的滞留可能是导致两水稻品种糙米中矿质元素含量降低的重要原因。     

Correlation analysis of mineral element contents and quality traits in milled rice (Oryza stavia L.)

The relationships among potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn) contents in milled rice (Oryza stavia L.) of 274 genotypes and the relationships between these mineral element contents and other rice quality traits including 3 cooking quality traits, 17 amino acid contents, and protein content were investigated. The results showed that there were significant correlations among most of mineral element contents. Mg, Fe, and Mn contents were significantly correlated with most of the other mineral element contents, while Cu content had significantly negative associations with the K and Mg contents of rice. The relationships between mineral element contents and cooking quality traits showed that gel consistency (GC) was significantly correlated with K, Cu, and Mn contents of rice. Amylose content (AC) was significantly associated with K, Na, Mg, Cu, and Mn contents. The alkali spreading value (ASV) had closely positive relationships with Ca, Mg, and Mn contents. In addition, 8 mineral element contents had obvious correlations with different amino acid contents. Mg, Ca, and Zn contents were significantly correlated with most of the 17 amino acid contents, but Na content did not correlate with amino acid contents except aspartic acid of rice. Furthermore, significant associations were found between protein content and Na, Mg, Zn, Cu, or Mn content. Six principal components were extracted to explain 84.50% of the total variances and contained the information provided by the original 29 variables according to the principal component analysis.     

Computer simulation of the interactions of glyphosate with metal ions in phloem

Essential nutrients such as trace metal ions, amino acids, and sugars are transported in the phloem from leaves to other parts of the plant. The major chelating agents in phloem include nicotianamine, histidine, cysteine, glutamic acid, and citrate. A computer model for the speciation of metal ions in phloem has been used to assess the degree to which the widely used herbicide glyphosate binds to Fe(3+), Fe(2+), Cu(2+), Zn(2+), Mn(2+), Ca(2+), and Mg(2+) in this fluid over the pH range of 8 to 6.5. The calculations show that glyphosate is largely unable to compete effectively with the biological chelating agents in phloem. At a typical phloem pH of 8, 1.5 mM glyphosate binds 8.4% of the total Fe(3+), 3.4% of the total Mn(2+), and 2.3% of the total Mg(2+) but has almost no effect on the speciation of Ca(2+), Cu(2+), Zn(2+), and Fe(2+). As the pH decreases to 6.5, there are some major shifts of the metal ions among the biological chelators, but only modest increases in glyphosate binding to 6% for Fe(2+) and 2% for Zn(2+). The calculations also indicate that over 90% of the glyphosate in phloem is not bound to any metal ion and that none of the metal-glyphosate complexes exceed their solubility limits.     

Chemical forms of iron in xylem sap from graminaceous and non-graminaceous plants

Graminaceous plants can take up iron-phytosiderophore complexes, whereas non-graminaceous plants absorb ferrous ions after the reduction of ferric compounds at the root cell membranes. The iron (Fe) in the roots may be transported to the aerial plant parts through the xylem. We compared the chemical forms in xylem sap collected from the cut stems of three graminaceous plants (rice [Oryza sativa L.], maize [Zea mays L.], barley [Hordenum vulgare L.]) and three non-graminaceous plants (tomato [Lycopersicon esculentum Mill.], soybean [Glycine max Merr.], castor bean [Ricinus communis L.]) grown in composite soils for the concentrations of iron and iron-chelating compounds (nicotianamine, phytosiderophores, citrate). We also fractionated the xylem saps by size-exclusion chromatography to gain insight into the chemical forms of iron. The Fe concentrations in the xylem sap ranged from 9 to 40 μM. Nicotianamine was found in the xylem sap from all the plants examined, with higher concentrations in the non-graminaceous plants. In contrast, phytosiderophores (2’-deoxymugineic acid and mugineic acid) were predominantly detected in the graminaceous plants. The concentrations of free citrate varied greatly (from 4 to 2200 μM) among the six plant species. The xylem sap iron in non-graminaceous plants may form two types of Fe-citrate, whereas in graminaceous plants, the bound Fe forms may be largely two types of Fe-citrate with various Fe-phytosiderophores.     

施氮量和穗粒肥比例对稻米营养品质及中微量元素含量的影响

通过田间试验研究了施氮量和穗粒肥比例对稻米氨基酸和蛋白质含量及Fe、Zn、Cu、Mn、Mg、Ca含量的影响。结果表明,稻米氨基酸和蛋白质含量均随着施氮量和穗粒肥比例的提高而增加,但施氮量和穗粒肥比例对氨基酸含量的影响程度因品种和氨基酸种类而异。合系39的氨基酸含量受施氮量和穗粒肥比例的影响较滇屯502的大;His、Val、Gly、Pro和Lys受施氮量和穗粒肥比例的影响较大,Ile、Arg、Asp和Glu受施氮量和穗粒肥比例的影响较小。稻米中Fe、Zn、Cu、Mn、Mg、Ca的含量和产量均随着施氮量的增加先上升后下降;从稻谷和蛋白质的产量、6种矿质元素的含量和产量看,供试粳型品种合系39的适宜施氮量较籼型品种滇屯502高。     

Interactive effects of aluminum and chromium stresses on the uptake of nutrients and the metals in barley

Aluminum (Al) and chromium (Cr) stresses often occur simultaneously in agricultural soils, and pose a great damage to crop growth, yield formation and product safety. In the current study, the influence of combined Al and Cr stresses on plant biomass, metal and nutrient contents was determined in comparison with that of Al or Cr stress alone. A hydroponic experiment was conducted to investigate the effect of pH, Al and Cr in the medium solution on the uptake of mineral elements as well as Al and Cr in the two barley genotypes differing in Al tolerance. Aluminum sensitive genotype Shang 70-119 had significantly higher Cr and Al contents in plants than Al-tolerant genotype Gebeina. Barley roots had much higher Al and Cr contents than above-ground plant parts. Chromium contents were much higher in the solution with pH 4.0 than in that with pH 6.5. Aluminum stress reduced phosphorus (P), calcium (Ca), magnesium (Mg), sulfur (S), copper (Cu), manganese (Mn), zinc (Zn) and boron (B) contents in roots and restrained potassium (K) and iron (Fe) from being translocated into shoots and leaves. Chromium stress resulted in reduced P, K, Mg, S, Fe, Zn and Mn contents in roots at pH 6.5 and P, K, Ca, Mg, S, Zn and Mn contents at pH 4.0. Translocation of all nutrients from roots to upper parts of plants was inhibited except Ca in pH 6.5 with Cr addition. Lower contents of all nutrients were observed at pH 4.0 as compared to pH 6.5. Combined stress of Cr and Al, on the whole, caused further reduction in mineral content in all plant parts of the two barley genotypes as compared to Al or Cr stress alone. Moreover, the reduction was more pronounced in Al sensitive genotype Shang 70-119.