Unsuitable Availability of Nutrients in Germinating Bean Embryos Exposed to Copper Excess

The influence of copper excess on germination rate, growth, minerals, carbohydrates, and amino acids supply in embryonic axis of bean seed was investigated. Compared to the control, Cu treatment caused a reduction in germination percent, embryo length, and accumulation of Ca, Fe, K, Mn, Zn, total soluble sugars, glucose, fructose, sucrose, and amino acids. Moreover, the nutrient concentrations, as well as the electrical conductivity were determined in the germination medium to quantify the extent of solute leakage. Such nutrients were lost in the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was associated with an enhancement in accumulation of malondialdehyde, major product of lipoperoxidation process which can be due to the stimulation in lipoxygenase activity in Cu-poisoned tissues.     

In vivo analysis of metal distribution and expression of metal transporters in rice seed during germination process by microarray and X-ray Fluorescence Imaging of Fe, Zn, Mn, and Cu

To investigate the flow of the metal nutrients iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) during rice seed germination, we performed microarray analysis to examine the expression of genes involved in metal transport. Many kinds of metal transporter genes were strongly expressed and their expression levels changed during rice seed germination. We found that metal transporter genes such as ZIP family has tendency to decrease in their expressions during seed germination. Furthermore, imaging of the distribution of elements (Fe, Mn, Zn, and Cu) was carried out using Synchrotron-based X-ray microfluorescence at the Super Photon ring-8 GeV (SPring-8) facility. The change in the distribution of each element in the seeds following germination was observed by in vivo monitoring. Iron, Mn, Zn, and Cu accumulated in the endosperm and embryos of rice seeds, and their distribution changed during rice seed germination. The change in the patterns of mineral localization during germination was different among the elements observed.     

Mobilization of Minerals to Developing Seeds of Legumes

The mineral nutrition of fruiting plants of Pisum sativum L.,Lupinus albus L. and Lupinus angustifolius L. is examined insand cultures supplying adequate and balanced amounts of essentialnutrients. Changes in content of specific minerals in leaves,pods, seed coat, and embryo are described. P, N and Zn tendto increase precociously in an organ relative to dry matteraccumulation, other elements more or less parallel with (K,Mn, Cu, Mg and Fe) or significantly behind (Ca and Na) dry weightincrease. Some 60–90 per cent of the N, P and K is lostfrom the leaf, pod and seed coat during senescence, versus 20–60per cent of the Mg, Zn, Mn, Fe and Cu and less than 20 per centof the Na and Ca. Mobilization returns from pods are estimatedto provide 4–39 per cent of the seeds' accumulations ofspecific minerals, compared with 4–27 per cent for testatransfer to the embryo. Endosperm minerals are of only minorsignificance in embryo nutrition. Comparisons of the mineral balance of plant parts of Lupinusspp. with that of stem xylem sap and fruit tip phloem sap supportthe view that leaves and pod are principal recipients of xylem-borneminerals and that export from these organs via phloem is themajor source of minerals to the seeds. Endosperm and embryodiffer substantially in mineral compostition from phloem sap,suggesting that selective uptake occurs from the translocationstream during seed development. Considerable differences are observed between species in mineralcomposition of plant organs and in the effectiveness of transferof specific minerals to the seeds Differences between speciesrelate principally to Ca, Na and certain trace elements.     

Dynamics of nutrient remobilisation from seed of wheat genotypes during imbibition,germination and early seedling growth

The changes in nutrient content of grain tissues and seedling parts of two wheat genotypes (Triticum aestivum L., Excalibur and Janz) with low or high seed Zn content were followed from imbibition to early seedling development (12 days). The grains were separated into seed coat, endosperm and embryo, while the seedlings were separated into roots and shoots. The dry weight of the seed coat did not change throughout the experimental period, whereas the endosperm weight declined rapidly from day 4 onward. The weight of embryo did not show any difference between and within cultivars. About a half of seed Zn was remobilised into shoot and roots during 12 days of growth, regardless of the initial seed Zn content in both genotypes. The seed coat contained 55–77% of the total seed nutrients in the two wheat genotypes, except in the case of S (around 40%). Manganese, Fe, Ca, K, and P were remobilised effectively from the seed coat as well as from the endosperm, while remobilisation of Zn and Cu was relatively less from the seed coat than from the endosperm. After 10 days of growth, all nutrients monitored were completely remobilised from the endosperm. Remobilised K was directed primarily into shoots; an increase in K content in shoots was relatively higher than the accumulation of dry matter, with a consequent increase in K concentration in shoot tissue. The remobilisation of some nutrients (eg. Fe, Ca and Zn) from various grain tissues during inbibition, germination and early growth is different from the remobilisation in more mature plants.     

Regulation of Mineral Redistribution in Pod-Bearing Soybean Explants

On the way from the roots to the seeds during reproductive developmentin soybean (Glycine max), a large proportion of the mineralspass through the leaves rather than travelling directly viathe xylem. This direct and indirect movement of mineral nutrientshas important implications for mineral redistribution, seeddevelopment and leaf senescence. Therefore, we have studiedthe role of cytokinin and mineral flux from the roots in regulatingmineral redistribution from the leaves to the seeds using explants,i.e. a leaf, a pod and a subtending stem segment, with theirbases immersed in treatment solutions. Thus, defined solutionscontaining cytokinin and/or minerals can be substituted forthe roots. When explants (excised at early-mid podfill) aresupplied H₂O only, leaf N, P, K, Mo, Mg, Zn, Fe, B, Cu, Ca,and Mn decline, ranging from 93% for Mo to 38% for Fe. In explantson H₂O, N, P, K, Mo, Mg, Zn, and Fe appear to be redistributedfrom the leaves to the seeds, while the B, Cu, Ca, and Mn lostfrom the leaves do not seem to move to the seeds. Although amixture of minerals resembling xylem sap can delay net lossof these elements from the leaves, it does not prevent the decreases.The cytokinin zeatin (4.6 µM) inhibits the loss of N,IC, Mo, Mg, Zn, Fe, B, Cu, Ca, and Mn from the leaves, but notthat of P. When combined with minerals, zeatin not only preventsthe loss of the minerals from the leaves but may even greatlyincrease them with the possible exception of Zn, Fe, and Cu.Supplying the mineral nutrient mixture increases the quantitiesof N, P, K, Mg, Cu, and B in the seeds but not Zn, Fe, Mn, Ca,and Mo. For those minerals, especially N, where zeatin inhibitsefflux from the leaves, it may reduce the amounts in the seeds,but it does not change P, K, Mg, and Ca. The accumulation andredistribution patterns of the different mineral nutrients showmany dissimilarities thereby suggesting differences in the controlof their distribution. Key words: Cytokinin, mineral transport, seed development, senescence     

Spatial X-ray fluorescence micro-imaging of minerals in grain tissues of wheat and related genotypes

Main conclusion

Wheat and its related genotypes show distinct distribution patterns for mineral nutrients in maternal and filial tissues in grains. X-ray-based imaging techniques are very informative to identify genotypes with contrasting tissue-specific localization of different elements. This can help in the selection of suitable genotypes for nutritional improvement of food grain crops.

Abstract

Understanding mineral localization in cereal grains is important for their nutritional improvement. Spatial distribution of mineral nutrients (Mg, P, S, K, Ca, Fe, Zn, Mn and Cu) was investigated between and within the maternal and filial tissues in grains of two wheat cultivars (Triticum aestivum Cv. WH291 and WL711), a landrace (T. aestivum L. IITR26) and a related wild species Aegilops kotschyi, using micro-proton-induced X-ray emission (µ-PIXE) and micro-X-ray fluorescence (µ-XRF). Aleurone and scutellum were major storage tissues for macro (P, K, Ca and Mg) as well as micro (Fe, Zn, Cu and Mn) nutrients. Distinct elemental distribution patterns were observed in each of the four genotypes. A. kotschyi, the wild relative of wheat and the landrace, T. aestivum L. IITR26, accumulated more Zn and Fe in scutellum and aleurone than the cultivated wheat varieties, WH291 and WL711. The landrace IITR26, accumulated far more S in grains, Mn in scutellum, aleurone and embryo region, Ca and Cu in aleurone and scutellum, and Mg, K and P in scutellum than the other genotypes. Unlike wheat, lower Mn and higher Fe, Cu and Zn concentrations were noticed in the pigment strand of A. kotschyi. Multivariate statistical analysis, performed on mineral distribution in major grain tissues (aleurone, scutellum, endosperm and embryo region) resolved the four genotypes into distinct clusters.     

Mineral Elements in Root of Wild Saposhnikovia divaricata and Its Rhizosphere Soil

Mineral elements are important components of medicinal herbs, and their concentrations are affected by many factors. In this study, Ca, Mg, Na, K, Fe, Mn, Cu, and Zn concentrations in wild Saposhnikovia divaricata and its rhizosphere soil collected from seven locations at two different times in China were measured, and influences of rhizosphere soil on those minerals in plant were evaluated. The results showed that mean concentrations of eight minerals in plant samples decreased in the order: Ca > Mg > Na > K > Fe > Zn > Mn > Cu, and those in the soil samples followed the following order: Na > Fe > Ca > K > Mg > Mn > Zn > Cu. Mean concentrations of Ca, Na, Mg, and K in plants were higher than those in soils, while higher mean concentrations of the other four minerals were found in soils. It was found that there was a positive correlation of Mg, Na, and Cu concentrations in the plant with those in the soil respectively, but a negative correlation of Mn concentration in plant with that in the soil. Except Ca, K, and Mn, the other five minerals in plant were all directly affected by one or more chemical compositions of soil. The results also indicate that pH value and concentrations of total nitrogen, Mg, Mn, and Cu in soil had significant correlations with multimineral elements in plant. In a word, mineral elements uptake of S. divaricata can be changed by adjusting the soil fertility levels to meet the need of appropriate quality control of S. divaricata.     

Contribution of mineral nutrients from source to sink organs in rice under different nitrogen fertilization

The pot experiment with three treatments of nitrogen (N) topdressing was performed with the japonica rice cultivar viz. Huaidao 5. Remobilization of nine mineral nutrients including N, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) was measured from the source organs including bracts, leaf, and sheath to sink rice grain. Experimental results showed considerable contribution of bracts to grain for N, Mg, and Zn, with the averages contributions of 5.96, 12.56, and 12.34%, respectively, indicating a positive role of rice bracts in N, Mg, and Zn remobilization during grain filling. By contrast, minor contribution of bracts to grain P, K, and Cu was revealed, with the contribution rate being 0.99, 3.90, and 3.05%, respectively. Further, a net increase in Ca and Fe concentrations of bracts was detected, implying that bracts function as a sink of these mineral nutrients. In addition, grains produced at a moderate level of N topdressing had higher Fe and similar Zn concentration in comparison with those at high N level, suggesting the possibility of N management for maintaining Fe and Zn level under high yielding conditions.     

Contents of pollutant and nutrient elements in rice and wheat grown on the neighboring fields

Because of recent agricultural policy to suppress rice production, a rather rare situation occurred in one prefecture in Japan that rice and winter wheat were grown in fields neighboring each other, rice being grown from May to October, and wheat from November to June of the next year. Grains of such rice and wheat were analyzed for cadmium (Cd) and lead (Pb) by atomic absorption spectrometry, and eight nutrient minerals by inductively coupled plasma emission spectrometry. Concentrations of nutrient minerals were higher in wheat grains than in unpolished rice grains (without husk), and similar trends were observed also for Cd and Pb. Flour obtained by milling of the wheat grains had significantly less Cd and nutrient minerals than the mother grains, and such reduction was also observed by treatment of unpolished rice to polished grain. Pb concentration was also reduced by the polishing of rice. Pb in wheat flour appeared to be higher than that in whole grain. Comparisons between the final edible forms of the two cereals showed that K and cu were higher in polished rice than in wheat flour and that such may also be the case for Cd, whereas the reverse was the case for Ca and Fe, and possibly for Pb.     

Applicability of food composition tables as a tool to estimate mineral and trace element intake of pre-school children in Japan: A validation study

Because dietary intakes of some minerals (including trace elements), especially iron (Fe), are insufficient for the needs of the general Japanese population, accurate estimation of mineral intake is important. This capability is especially necessary to preserve the health of Japanese children. Therefore, the current version of food composition tables (FCT) in Japan was evaluated for validity as tools to estimate dietary intake of minerals for children. For this purpose, 24 h food duplicate samples were collected from 292 pre-school children in Miyagi prefecture, Japan. From the weights of items and food codes, intakes of nine minerals were estimated taking advantage of the FCT. In parallel, amounts of minerals in each duplicate samples were instrumentally measured by ICP-AES for Ca, Cu, Fe, Mg, Mn, P and Zn, and by flame AAS for K and Na, both after wet-ashing. The distributions of the mineral amounts were essentially normal. The comparison of the FCT-based estimates (E) and instrumental measures (M) showed that the E/M ratio was close to 1 for Ca, K, Mn, P and Zn, suggesting that E may be a surrogate of M for Ca, K, Mn, P and Zn on a group basis. The ratio being larger than 1.2 for Cu, Fe, Mg and Na indicates that a risk of over-estimation exists when E is relied upon in place of M. On an individual basis, significant differences were detected for all 9 minerals suggesting that the use of E as a surrogate for M should be practiced with care for the estimation of mineral intake.     

Biofortification of durum wheat (Triticum turgidum L. ssp. durum (Desf.) Husnot) grains with nutrients

Durum wheat (Triticum turgidum L. ssp. durum (Desf.) Husnot) was grown under conditions to promote mineral biofortification at the grain level. Along plant development, biomass accumulation and the kinetics of nutrients accumulation were assessed, identifying the nutrient fluxes of roots and shoots, and the timescale constraints of crop biofortification. Plants were grown under environmentally controlled conditions, submitted to four increasing concentrations of nutrient solutions (1-, 2-, 4- and 6-fold) of micro- (Fe, Zn, Cu and Mn) and macronutrients (Ca, K, P and Mg). The threshold of mineral toxicity was not reached as evaluated through plant biomass accumulation, but considering grain yield, the twofold nutrient concentration was the best treatment for biofortification. In the different treatments, the contents and the mineral unrests of roots uptake and shoots translocation varied, at different magnitudes and trends, before the onset of booting and from the physiological maturity onwards. Except for Cu, all mineral nutrients were mainly detected in the bran and embryo of the grains; therefore, the production of biofortified pasta for human consumption requires the use of integral semolina.     

Energy-Dispersive X-ray analysis of the mineral content of corn bran treated in vitro and by passage through the pig Gastrointestinal tract

Energy-dispersive X-ray (EDX) analysis was tested as a method for examining the mineral contents of corn bran loaded in vitro or passed through the GI tract of pigs. Particles of dry-milled corn pericarp treated in vitro or retrieved from the stomach, ileum, and colon of killed pigs were prepared as microtomed bulk specimens directly embedded in resin. Because of heterogeneity caused by differences in substrate cell density and mineral content, X-ray count averages for a number of different specimens had a coefficient of variation greater than or equal to 0.24. Detectable amounts of K, Ca, S, and P, but not Na, Cu, Fe, or Zn were found in specimens of initial bran. Although detectable concentrations of Cu, Fe and Zn could be loaded in vitro, these elements generally were not detected in bran retrieved from the pig GI tract. During GI tract passage, sodium was loaded onto bran mainly in the small intestine and unloaded in the large intestine. Calcium was loaded in the stomach and unloaded mainly in the small intestine. At each GI tract location, content of Na, Ca, K, and P in retrieved bran was greater than in the initial bran. EDX microprobe methods can be applied successfully to plant tissues treated in vitro and in vivo to investigate interactions with minerals in a diet.     

黑米中矿质元素铁、锌、锰、磷含量的遗传效应研究

采用禾谷类作物种子胚乳数量性状模型,分析黑米稻品种双列杂交Ｆ１和Ｆ２种子的Ｆｅ、Ｚｎ、Ｍｎ、Ｐ含量的遗传效应。结果表明,４种矿质元素含量同时受制于种子直接遗传效应、母体效应和细胞质作用影响。其中,Ｆｅ、Ｚｎ、Ｍｎ含量的种子直接效应比母体效应和细胞质效应的作用更大;Ｐ含量则主要受种子直接加性、母体加性和显性效应共同作用。Ｆｅ、Ｚｎ、Ｍｎ含量的种子直接遗传率较高,在杂种早代分别结合农艺性状选择单株上各     

Redistribution of Nutrient Elements from Cotyledons of Two Species of Annual Legumes During Germination and Seedling Growth

The distribution of dry matter and various mineral nutrientsbetween testa and embryo of seeds of Lupinus albus and L. angustifoliusis described It was found that lupin seeds at either end ofa pod contained less dry matter and minerals than seeds in themiddle of the fruit. The transport of dry matter, N, P, K, S,Ca, Mg, Na, Fe, Zn, Mn and Cu from cotyledons of parent seedsof both species to the seedling axis was measured from germinationto the time of cotyledon death. N, P, K and S were retrievedfrom cotyledons with over 90 per cent efficiency, dry matter,Mg, Na, Fe, Zn, Mn and with 59–90 per cent efficiency,and Ca with 26–31 per cent efficiency. There was littlechange in the efficiency of nutrient retrieval from cotyledonswhen seedlings were grown in different culture media. Both speciesshowed a linear relationship between the loss of each elementand dry matter throughout the experiment, and a similar proportioningbetween root and shoot of the amount of a specific nutrientmobilized from cotyledons of parent seeds. Lupinus albus L., Lupinus angustifolius L., lupin, transport, of dry matter and mineral nutrients     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.     

籼型黑米粒形性状的遗传效应及其与矿质元素含量的遗传相关性

采用禾谷类作物种子数量性状的遗传模型,分析了灿型黑米稻品种双列杂交F1和F2种子的粒重,粒长,粒宽和粒长／粒宽等粒形性状的遗传效应及其与米粒中矿质元素Fe,Zn,Mn和P含量的遗传相关性,结果表明：4种粒形性状同时受制于种子直接遗传效应,母体效应和细胞质作用影响,其中种子直接遗传效应比母体效应和细胞质效应的作用更大,且种子直接遗传效应以加性效应占主导,粒重,粒宽和粒长／粒宽的种子直接遗传率较高,杂种早代单粒选择效果较好,粒长的种子直接遗传率和母体遗传率均属中等,较高世代的杂种进行单株选择和单粒选择均有一定效果,4种粒形性状与其米粒中矿质元素Fe,Zn,Mn和P含量表现较强的种子直接加性相关,直接显性相关,细胞质相关,母体加性相关和母体显性相关,在特种稻育种实践中,可以通过粒形性的间接选择,达到改良其矿质元素含量等营养品质性状的目标。     

Nutritional status and risks of potentially toxic elements in some paddy soils and rice tissues

This experiment was conducted to investigate the potential risk of toxic elements in paddy soils and rice straws, bran, and husked grains in Kuchesfahan, Gilan, Iran. The average content of total and DTPA-extractable of Cd, Cu, Fe, Mn, Ni, Pb, and Zn were 7.0, 26.3, 20728.8, 1516.7, 43.8, 16.6, and 211.8?mg kg^?1, and 0.32, 14.1, 97.3, 63.4, 1.7, 4.8, and 56.2?mg kg^?1, respectively. In addition, the average content of Cd, Cu, Fe, Mn, Ni, Pb, and Zn in rice grain was 0.16, 2.4, 135.5, 34.1, 2.0, 0.6, and 15.0?mg kg^?1, respectively. The average transfer factor for Cd, Cu, Fe, Mn, Ni, Pb, and Zn from soil to straw was 0.38, 0.16, 0.004, 0.13, 0.3, 0.04, and 0.09, respectively. The average values of estimated daily intake for Cd, Cu, Fe, Mn, Ni, Pb, and Zn through rice consumption for adult are respectively, estimated to be 0.0004, 0.005, 0.32, 0.08, 0.005, 0.0015, and 0.035?mg kg^?1 body weight per day. There was no health risk index (HRI) values for adult greater than 1 (except three samples for Fe, and one sample for Mn and Cd); indicated that intake of single metal through the consumption of rice was safe. The average of heath index (HI) value for rice consumption was 0.33 and 0.35 for adult and children, respectively. Therefore, combination of several potentially toxic elements may not cause risk to local residents. Spatial distributions of HRI were obtained for potentially toxic metals in husked grains.     

Quantitative trait locus mapping for seed mineral concentrations in two Arabidopsis thaliana recombinant inbred populations

Biofortification of foods, achieved by increasing the concentrations of minerals such as iron (Fe) and zinc (Zn), is a goal of plant scientists. Understanding genes that influence seed mineral concentration in a model plant such as Arabidopsis could help in the development of nutritionally enhanced crop cultivars. Quantitative trait locus (QTL) mapping for seed concentrations of calcium (Ca), copper (Cu), Fe, potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and Zn was performed using two recombinant inbred line (RIL) populations, Columbia (Col) x Landsberg erecta (Ler) and Cape Verde Islands (Cvi) x Ler, grown on multiple occasions. QTL mapping was also performed using data from silique hulls and the ratio of seed:hull mineral concentration of the Cvi x Ler population. Over 100 QTLs that affected seed mineral concentration were identified. Twenty-nine seed QTLs were found in more than one experiment, and several QTLs were found for both seed and hull mineral traits. A number of candidate genes affecting seed mineral concentration are discussed. These results indicate that A. thaliana is a suitable and convenient model for discovery of genes that affect seed mineral concentration. Some strong QTLs had no obvious candidate genes, offering the possibility of identifying unknown genes that affect mineral uptake and translocation to seeds.     

The expression of heterologous Fe (III) phytosiderophore transporter HvYS1 in rice increases Fe uptake,translocation and seed loading and excludes heavy metals by selective Fe transport

Many metal transporters in plants are promiscuous, accommodating multiple divalent cations including some which are toxic to humans. Previous attempts to increase the iron (Fe) and zinc (Zn) content of rice endosperm by overexpressing different metal transporters have therefore led unintentionally to the accumulation of copper (Cu), manganese (Mn) and cadmium (Cd). Unlike other metal transporters, barley Yellow Stripe 1 (HvYS1) is specific for Fe. We investigated the mechanistic basis of this preference by constitutively expressing HvYS1 in rice under the control of the maize ubiquitin1 promoter and comparing the mobilization and loading of different metals. Plants expressing HvYS1 showed modest increases in Fe uptake, root‐to‐shoot translocation, seed accumulation and endosperm loading, but without any change in the uptake and root‐to‐shoot translocation of Zn, Mn or Cu, confirming the selective transport of Fe. The concentrations of Zn and Mn in the endosperm did not differ significantly between the wild‐type and HvYS1 lines, but the transgenic endosperm contained significantly lower concentrations of Cu. Furthermore, the transgenic lines showed a significantly reduced Cd uptake, root‐to‐shoot translocation and accumulation in the seeds. The underlying mechanism of metal uptake and translocation reflects the down‐regulation of promiscuous endogenous metal transporters revealing an internal feedback mechanism that limits seed loading with Fe. This promotes the preferential mobilization and loading of Fe, therefore displacing Cu and Cd in the seed.     

南瓜茎、叶、花的营养成分分析

对南瓜茎、叶、花等部位进行了粗脂肪、粗蛋白、粗纤维、总糖、Vc等主要营养成分和K、Na、Ca、Mg、Zn等矿质元素的测定。结果表明,南瓜茎、叶、花营养丰富,各种营养成分较为全面。南瓜叶中粗脂肪、粗蛋白、Vc、K、Ca、Mg、Mn、Fe、Zn等成分含量均高于南瓜茎和南瓜花。与其他8种常见蔬菜相比,主要营养成分和矿质元素含量也远远高于这8种蔬菜。为南瓜茎、叶、花的菜用价值提供了科学依据,也为增加人们的膳食营养、改变餐桌食品花样、开发蔬菜资源及其利用价值提供了参考。