Si在燕麦籽粒中的富集及其与其它8种元素的关系

通过环境扫描电镜结合X射线电子探针显微分析技术,对22个基因型的燕麦籽粒皮层、糊粉层、近糊粉层和颖果中部的Si含量进行测定.结果表明,Si元素在燕麦籽粒不同部位的含量有明显差异,皮层和糊粉层Si含量较高,近糊粉层和颖果中部含量较低,在颖果中Si主要富集在糊粉层中;而且不同基因型燕麦籽粒同一部位或不同部位Si的积累量也有较大差异,这可能是由遗传差异引起的.糊粉层中的Si含量影响着近糊粉层和颖果中部的Si含量.另外,籽粒不同部位Si含量与P、Ca、Mg、S、Al、Pb含量之间存在显著或极显著的非线性关系,颖果中部的Si含量与K、Cd含量之间不存在显著的非线性关系.说明Si在燕麦籽粒中富集的同时也影响着P、Ca、Mg、S、Al、Pb等元素的富集.     

Ca在水稻籽粒中的富集及其与其它7种元素的关系

通过环境扫描电镜结合X射线电子探针显微分析技术,对21种不同基因型的水稻籽粒颖壳内、外表面以及颖果表面、糊粉层、近糊粉层和米中部的Ca含量进行测定。结果表明,Ca元素在水稻籽粒不同部位的含量有明显差异,颖壳内外表面和颖果表面Ca含量较高,近糊粉层和颖果中部含量较低,在颖果中Ca主要富集在糊粉层中;而且不同基因型水稻籽粒同一部位或不同部位Ca的积累量也有较大差异,这可能是由遗传差异引起的。糊粉层中的Ca含量影响着颖壳外表面、颖果表面、近糊粉层和米中部的Ca含量。另外,籽粒不同部位Ca含量与P、Mg、K、Si、Al、Cd含量之间存在显著或极显著的非线性关系,与Pb含量之间不存在显著的非线性关系。说明Ca在水稻籽粒中富集的同时也影响着P、Mg、K、Si、M、Cd等元素的富集。     

油菜和玉米花粉粒中元素分布的研究

以油菜和玉米花粉为材料 ,应用扫描电镜及能谱仪技术对花粉中内外元素分布进行了初步研究。结果表明 :花粉粒萌发沟区与非萌发沟区 ,花粉壁与原生质内外的不同部位 ,Fe、Zn、Si、Al、Ca、P、S、Mg、K、Cl、Cu、Mn、Co及Ni1 4种元素组成有很大差异 ;两种花粉的萌发沟区都未检测出Fe元素 ,而非萌发沟区的Fe元素相对含量为 1 .1 2 %～ 3 68% ;花粉壁中比花粉原生质中更富含Si,Ca,K ,Cl等元素。本项研究为蜜源植物花粉的开发和利用提供了有价值的资料。     

油菜和玉米花粉粒中元素分布的研究

以油菜和玉米花粉为材料,应用扫描电镜及能谱仪技术对花粉中内外元素分布进行了初步研究。结果表明：花粉粒萌发沟区与非萌发沟区,花粉壁与原生质内外的不同部位,Fe、Zn、Si、Al、Ca、P、S、Mg、K、Cl、Cu、Mn、Co及Ni 14种元素组成有很大差异;两种花粉的萌发沟区都未检测出Fe元素,而非萌发沟区的Fe元素相对含量为1.12%～368%;花粉壁中比花粉原生质中更富含Si,Ca,K,Cl等元素。本项研究为蜜源植物花粉的开发和利用提供了有价值的资料。     

应用电子探针对植物根际和根内营养元素微区分布的探讨

用电子探针可检测出玉米、大豆根际和根内含有Na,Mg,Al,Si,P,S,Cl,K,Ca,Ti,Fe,Cu和Zn 13种元素。这些元素在根际土壤、粘液层和根组织内的含量分布有一定的规律性。除Si,Al,Ca,Fe在根际土壤中峰值较高外,Ti仅在土壤中达到可检测量;S,Fe和Zn富集在粘液层,Mg,P,Cl只在根组织内才有较明显的峰。这些规律可作为区分根—土界面的参考指标。K含量在根内明显高于根际土壤,并由表皮层到中柱径向增加;Ca则与K不同,且受植物种类的影响。     

霍山石斛组培苗移栽后微观结构与微区元素的变化研究

采用扫描电镜及X射线能谱仪技术,研究霍山石斛组培苗移栽后各器官组织的微观结构和所含元素的变化,以了解霍山石斛组培苗生长发育以及药效成分的状况。结果表明:(1)霍山石斛组培苗移栽2个月后,根增粗近1倍,具有根被,且根被细胞壁的网络状增厚更加明显,表皮、皮层、中柱发育分化更加完善,Mg、Si、Cl、S、K、Ca元素含量提高,其中Ca增长了2.76倍。(2)茎表面纵向凹陷增多,内部结构致密,维管束发育较为完善,细胞内充满物质,Mg、Si、Cl、S、K、Ca、Fe、Cu、Zn元素含量增多,尤其是K和Fe分别增长了3.25倍和4.61倍。(3)叶增厚,具有了角质层,气孔形状更加饱满,叶肉细胞内含物丰富,Mg、Si、Cl、S、K、Ca、Fe、Mn、Zn的含量显著上升,其中K升高了17倍。(4)与根、叶相比,茎中所富集的元素种类最多。研究认为,霍山石斛试管苗移栽后,生长发育趋向完善,各项功能增强,细胞内含物质增多,元素成分丰富并且含量提高,体现出对移栽环境的良好适应性。     

大兴安岭地区笃斯越橘基生枝条矿质养分特性

以大兴安岭地区3种主要立地类型的笃斯越橘为试验材料,通过分析由灌丛基部萌生的1~2年生(S1)、3年生(S2)、4年生(S3)、5年生(S4)、趋于衰老的多年生(S5)枝条叶片和茎部,以及衰老枝条(S6)的N、P、K、Ca、Mg、Mn含量分布规律及其与新梢生长的关系,明确矿质元素在笃斯越橘不同年龄基生枝上叶片及茎部的分布特性,探索矿质营养与笃斯越橘树体生长发育及衰老更新的关系。结果表明:(1)6种元素在不同年龄枝条分布呈现不同的规律,其中,N、P、K随基生枝条年龄增加大致呈下降趋势,叶片和茎部分别在S5、S6时期降到最小值;Ca在衰老枝条上含量最高,Mg元素在S1时期叶片上分布较高;Mn在不同年龄基生枝中波动较小,水湿地、山地类型叶片Mn元素随枝龄增加而提高,茎部则先增后减,在S5时期分布最高;N、P、K、Ca、Mg含量表现为叶片明显高于茎部,而塔头草甸类型茎部Mn略高于叶片,且茎部Mn含量高达2 000mg·kg~(-1)。(2)笃斯越橘的新梢生长量与叶片K、Mg以及茎部N、K、Mg含量呈极显著正相关关系,与叶片Ca、Mn以及茎部Ca含量呈显著或极显著负相关关系。(3)典型相关分析结果显示,影响笃斯越橘新梢生长量的矿质元素因子因基生枝条年龄而异;S1时期主要与叶片Mg含量有关,S2~S4阶段受茎部K、Ca、Mg影响最大,S5时期主要受叶片Ca含量影响。(4)笃斯越橘的衰老可能与Ca积累有关。     

鼎湖山南亚热带地区植物的叶片矿质元素

本文分析了64种植物叶片中19种矿质元素的含量,讨论了不同生活型植物对矿质元素的吸收和积累的影响。研究表明:64种植物叶片的19种矿质元素的频数分布呈对数正态分布。不同植被型及生活型,子叶数及光合途径对叶片矿质元素含量和组成有显著的影响。密林植物含较多P和Mg,有较高的微量元素/大量元属比;疏林植物含较多Al和Mn;木本型植物缺Mo;草本型植物积集较多的K、Ca、Si、Mg、P和Ti。草本中的双子叶植物平均矿质元素总量高于单子叶,尤以Ca与B较为明显。单子叶中的C_4植物叶片含较多的Na。     

英罗港红树植物群落不同演替阶段植物元素分布及其与土壤肥力的关系

 根据广西英罗港红树植物群落的演替过程, 研究了5个主要演替阶段红树植物群落优势种地上部分的7种元素 （N、P、K、Ca、Mg、Na、Cl）含量、群落元素积累量及其与土壤肥力的关系。结果表明：1）红树植物不同器官元素含量大小为：N、P、K均为花果＞叶＞枝＞皮＞干,Ca为皮＞枝、叶＞花果＞干,Mg为花果＞叶＞皮＞枝＞干, Na、Cl为叶、花果＞皮＞枝＞干;2）同一器官中各元素含量均以Cl、Na最多, 其次是N、Ca、K, 然后是Mg, 最少是P;3）随着进展演替, 红树植物群落优势种的N、P、K含量呈明显减少     

伯乐树种子不同发芽阶段矿质元素含量的动态变化

伯乐树(Bretscheneidera sinensis Hemsl.)是我国特有珍稀的孑遗植物和国家一级重点保护野生植物。探讨伯乐树种子发育过程中Mg、Ca、Na、P、K、Fe等矿质元素的动态变化与累积规律,对理解伯乐树的生理生化特点以及播种育苗、扩大种群数量具有重要意义。研究表明:伯乐树种子中的矿质元素含量依次为P﹥K﹥Ca﹥Na﹥Mg﹥Fe;在不同萌发阶段的伯乐树种子中,Mg、P、K三种元素含量逐步升高,而Ca、Na、Fe三种元素含量则表现为先增后降的动态变化。     

X-ray Analysis Studies of Elements Stored in Protein Body Globoid Crystals of Triticum Grains

Energy-dispersive x-ray analysis was used to investigate the elemental storage within protein bodies, specifically the globoid crystals, in grains of wheat. Areas of the grain investigated included various parts of the embryo, the aleurone layer plus starchy endosperm near the embryo and the aleurone layer plus starchy endosperm farthest from the embryo. Variations did occur grain-to-grain, cell-to-cell and, in certain regions, intracellularly. No protein bodies with electron-dense globoid crystals were found in the starchy endosperm. Generally globoid crystals contained P, K, and Mg in all areas investigated. Globoid crystals from the aleurone layer farthest from the embryo on occasion contained Ca, whereas aleurone globoid crystals near the embryo sometimes contained Fe. In most of the embryo regions examined, a few globoid crystals contained Ca along with P, K, and Mg. No specific pattern to the Ca distribution could be found. Welldefined elemental distribution occurred with Mn. Manganese was found only in globoid crystals located in the base and midregions of the stele in the radicle. Thus, in wheat there is some specific distribution of minerals dependent upon cell type and/or position in the grain.     

Ultrastructure and elemental composition of dormant and germinating Diplodia maydis spores.

The ultrastructure of Diplodia maydis spores was studied in thin sections with a transmission electron microscope. Storage vacuoles were evenly distributed in the two cells. Some of the vacuoles that contained a dense osmiophilic sphere(s) were surrounded by a membrane, and had membranous aggregates around their periphery. The sport wall was composed of an electron-dense layer and an electron-translucent layer. An inner cytoplasmic membrane was present. Dormant and germinating spores were studied with scanning electron microscopy and also with a Si (Li) energy-dispersive X-ray analyzer. The dormant spore was ovate and usually two-celled with a central septum. Germination proceeded via a germ tube from the side of one end of the cell. Of several methods for preparation of specimens for X-ray analysis studied, freeze-dried spores mounted on carbon stubs and then further carbon coated gave the best results. X-ray analyses revealed that spore populations contained large amounts of Si, P, Cl, and K, smaller amounts of S and Ca, and trace amounts of Mg and Al. Analyses of single spores revealed high K and Cl and low P and Mg at one end of the cell with concomitant low K and Cl and high P and Mg in the central portion and other end of the cell. In two-celled germinating spores, high K and Cl occurred in the end of the nongerminating spore cell, whereas the germinating cell contained high P and Mg and low K and Cl. X-ray image maps revealed that K and Cl were located together at one end of the spore.     

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.     

New insights into globoids of protein storage vacuoles in wheat aleurone using synchrotron soft X-ray microscopy

Mature developed seeds are physiologically and biochemically committed to store nutrients, principally as starch, protein, oils, and minerals. The composition and distribution of elements inside the aleurone cell layer reflect their biogenesis, structural characteristics, and physiological functions. It is therefore of primary importance to understand the mechanisms underlying metal ion accumulation, distribution, storage, and bioavailability in aleurone subcellular organelles for seed fortification purposes. Synchrotron radiation soft X-ray full-field imaging mode (FFIM) and low-energy X-ray fluorescence (LEXRF) spectromicroscopy were applied to characterize major structural features and the subcellular distribution of physiologically important elements (Zn, Fe, Na, Mg, Al, Si, and P). These direct imaging methods reveal the accumulation patterns between the apoplast and symplast, and highlight the importance of globoids with phytic acid mineral salts and walls as preferential storage structures. C, N, and O chemical topographies are directly linked to the structural backbone of plant substructures. Zn, Fe, Na, Mg, Al, and P were linked to globoid structures within protein storage vacuoles with variable levels of co-localization. Si distribution was atypical, being contained in the aleurone apoplast and symplast, supporting a physiological role for Si in addition to its structural function. These results reveal that the immobilization of metals within the observed endomembrane structures presents a structural and functional barrier and affects bioavailability. The combination of high spatial and chemical X-ray microscopy techniques highlights how in situ analysis can yield new insights into the complexity of the wheat aleurone layer, whose precise biochemical composition, morphology, and structural characteristics are still not unequivocally resolved.     

Correlation between 25 element contents in mane hair in riding horses and atrioventricular block

The influence of atrioventricular block (AV-block) on the trace elemental status in a horse hair was studied. The particle-induced X-ray emission (PIXE) method has provided a reliable, rapid, easy, and relatively inexpensive diagnostic method. Twenty-five elements (Al, Br, Ca, Cl, Co, Cu, Cr, Fe, Hg, K, Mg, Mn, Na, Nb, Ni, P, Pb, Rb, S, Se, Si, Ti, Y, and Zn) in mane hair and serum were measured by the PIXE method. A horse hair with first- and second-degree AV-block contained significantly greater amounts of Br, Ca, Sr, and Zn than those of horses without electrocardiographic abnormalities, whereas there was no significant differences in the elemental contents of the serum of the both groups. Those results in contents of a horse hair suggest that the evaluation of the degree of ionic imbalance by this method might be used to predict the susceptibility of a horse to heart disease much before symptoms appear.     

Major element chemistry,weathering and element yields for the Caura River drainage,Venezuela

The Caura River, a major tributary of the Orinoco River, was sampled at bi-weekly intervals for two years. Because the watershed is covered with undisturbed forest overlying a Precambrian shield, the water of the Caura River has low conductivity (mean, 15 uS/cm), contains small amounts of particulate material (mean, 11 mg/1), and is slightly acidic (median pH, 6.8). Concentrations of total dissolved solids vary less than two-fold in response to the seasonal ten-fold variation in discharge; concentrations of particulate material vary more (ten-fold) and are lowest at the time of peak discharge. Seasonal changes in concentrations of Si, major metal cations, and hydrogen ion are complementary to each other and indicate regular seasonal changes in weathering rates. Measurements of bulk atmospheric deposition and the observed runoff yield of Cl and S were used in estimating the basin-wide atmospheric deposition of major elements, which were as follows (kg/ha/yr): Ca, 1.3; Mg, 0.29; Na, 8.2; K, 1.0; Cl, 12; S, 2.8; P, 0.14. Element ratios show that terrestrial sources contribute strongly to the atmospheric deposition of Ca, K, S, and P. From the atmospheric contributions and runoff yields, watershed retention was computed for major elements with reference to Si. The watershed accumulates Al, Fe, and P, whereas losses of Ca, Mg, Na, K, and S originating from non-atmospheric sources exceed the relative loss rates of Si. The rock weathering rate based on Si is 1.8 cm/ 1,000 years. Although significant amounts of Ca, Mg, Na, and K are found in atmospheric deposition, the dominant influence on the mass balances of these elements is weathering rather than deposition. Weathering has a trivial influence on the cycles of Cl and S. Both atmospheric deposition and weathering are important in the mass balance of P. The ecosystem does not effectively conserve most biologically active elements (Ca, Mg, Na, K). The ecosystem conserves significant amounts of phosphorus (31% of total input), but probably by abiotic mechanisms.     

水稻籽粒矿质元素含量遗传及主要农艺性状相关性分析

通过了解水稻子粒钙、镁、铜、铁、锌和硒等矿质元素含量,以绿旱1号作为父本与102S、KD36S、7HS012及7HS013不育系为母本进行配组,对父本与杂交后代主要农艺及经济性状、水稻子粒中的矿质元素含量进行了遗传分析,并对各杂交后代的主要农艺性状和子粒中矿质元素含量以及各矿质元素含量间进行了相关性分析.结果表明,杂交后代农艺及经济性状多数表现出超高亲分离现象,且LK3的农艺及经济性状均表现为最好.水稻子粒矿质元素含量与部分农艺和经济性状存在明显的正相关或负相关关系,且K、Mg、Zn、Se等元素含量与水稻产量密切相关.水稻子粒中矿质元素含量大小依次为P＞K ＞Mg ＞S＞ Ca＞ Mn ＞Fe ＞Zn ＞Cu ＞Se,4个杂交后代的K元素含量表现出超高亲分离现象,LK2、LK3和LK4的Fe元素含量也表现出超高亲分离现象.水稻子粒大量与微量元素之间相关性最高,微量元素之间相关性次之,大量元素之间相关性最小,以7HS012不育系为母本得到的杂交后代农艺性状表现较好,矿质元素含量最高,7HS013次之,其他不育系表现一般.本研究为选育出耐旱及营养价值高的水稻新品种母本的选择提供了理论依据.