外源亚精胺对低氧胁迫下黄瓜根系多胺含量和呼吸代谢酶活性的影响

采用营养液水培,研究了根际低氧胁迫下外源亚精胺对2个抗低氧能力不同的黄瓜品种(‘中农八号’和‘绿霸春四号’)根系中多胺含量和呼吸代谢相关酶活性的影响.结果表明,单纯低氧处理下,黄瓜幼苗根系中腐胺、亚精胺和精胺含量显著提高,异柠檬酸脱氢酶(IDH)和琥珀酸脱氢酶(SDH)活性显著降低,乳酸脱氢酶(LDH)、乙醇脱氢酶(ADH)和丙酮酸脱羧酶(PDC)活性显著提高.同时,与抗低氧能力弱的‘中农八号’相比,抗低氧能力强的‘绿霸春四号’根系LDH活性增加幅度较低,ADH活性增加幅度较高,IDH和SDH活性降幅也较小;外源亚精胺能显著提高低氧胁迫下黄瓜幼苗根系中亚精胺和精胺含量,降低腐胺含量;根系中LDH、ADH和PDC活性降低,IDH和SDH活性升高,说明黄瓜幼苗根系中较高的亚精胺、精胺含量可能有利于提高根系有氧呼吸能力,缓解低氧胁迫对植株的伤害.     

低氧胁迫下24-表油菜素内酯对黄瓜幼苗叶片光合特性及多胺含量的影响

采用1/2 Hoagland营养液培养,研究了低氧胁迫下24-表油菜素内酯(EBR)对黄瓜幼苗叶片光合特性及多胺含量的影响.结果表明：低氧胁迫下黄瓜幼苗的净光合速率(P_n)、气孔导度(g_s)、蒸腾速率(T_r)、胞间CO₂浓度(C_i)显著下降,而叶绿素含量显著提高,幼苗生长受抑;低氧胁迫显著提高了黄瓜幼苗叶片的腐胺(Put)、亚精胺(Spd)、精胺(Spm)、多胺(PAs)含量和Put/PAs,但降低了(Spd+Spm) /Put.低氧胁迫下,外源EBR不仅显著提高了黄瓜幼苗的P_n、g_s、T_r及叶绿素含量,也显著提高了黄瓜幼苗叶片的游离态Spm、结合态Spd、Spm及束缚态Put、Spd、Spm含量,促进了PAs的进一步积累,且降低了Put/PAs,提高了(Spd+Spm)/Put．可见,外源EBR调节了黄瓜幼苗内源多胺含量及形态的变化,维持了较高的光合性能,促进了叶面积和干物质量的显著增加,缓解了低氧胁迫对黄瓜幼苗的伤害.     

外源亚精胺对根际低氧胁迫下黄瓜幼苗根系多胺含量和抗氧化酶活性的影响

采用营养液水培,研究了根际低氧胁迫下外源亚精胺对两个抗低氧能力不同的黄瓜(Cucumis sativus)品种(‘中农8号’和‘绿霸春4号’)根系中多胺含量和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的影响。结果表明,外源亚精胺能显著提高低氧胁迫下黄瓜幼苗根系中亚精胺和精胺含量,降低腐胺含量,同时,根系中SOD、POD、CAT活性也相应提高,使得幼苗鲜重和干重明显增加;单纯低氧处理及外源亚精胺的加入,抗低氧能力较强的品种‘绿霸春4号’较抗低氧能力较弱的品种‘中农8号’根系中抗氧化酶活性高。黄瓜幼苗根系中较高的亚精胺、精胺含量和较低的腐胺含量可能有利于提高抗氧化酶活性,增强幼苗的低氧逆境适应能力。     

钙对低氧胁迫下黄瓜幼苗体内多胺及多胺氧化酶的影响

以‘中农8号’黄瓜品种为实验材料,采用营养液栽培法研究了钙对根际低氧胁迫下黄瓜幼苗体内多胺(PAs)含量及多胺氧化酶(PAO)活性的影响。结果表明:(1)各处理黄瓜幼苗根系和叶片中的PAs含量以及3种形态的腐胺(Put)、亚精胺(Spd)、精胺(Spm)含量均表现为低氧高钙(8 mmol.L-1Ca2 )>低氧常钙(2 mmol.L-1Ca2 )>低氧缺钙(0 mmol.L-1Ca2 )>通气常钙(2 mmol.L-1Ca2 )处理,而PAO活性却表现出相反的趋势(通气常钙>低氧缺钙>低氧常钙>低氧高钙),且处理间大多存在显著差异(P<0.05);根系中的PAs含量明显高于叶片,而PAO活性明显低于叶片。(2)黄瓜幼苗体内3种形态的PAs以游离态含量最高,其次是结合态,最低为束缚态;游离态和结合态PAs在叶片中均以Spd为主,在根系中均以Put为主,束缚态PAs含量在根系和叶片中均为Spd>Put>Spm。研究表明,在低氧胁迫下,营养液加钙引起黄瓜幼苗体内多胺含量的上升和PAO活性下降,钙参与了黄瓜幼苗体内多胺的代谢过程,对缓解低氧胁迫有重要作用。     

D-精氨酸对低氧胁迫下黄瓜幼苗根系多胺含量和无氧呼吸代谢的影响

采用营养液水培法,研究了根际低氧胁迫下D-精氨酸（D-Arg）对两个抗低氧能力不同的黄瓜品种根系中多胺含量和无氧呼吸代谢的影响.结果表明,低氧处理下,黄瓜幼苗根系中多胺含量显著增加,无氧呼吸代谢能力提高;与抗低氧能力弱的‘中农八号’相比,抗低氧能力强的‘绿霸春四号’根系中乙醇发酵活性较高,乳酸发酵活性较低;低氧胁迫下,D-精氨酸能显著降低黄瓜幼苗根系中腐胺、亚精胺和精胺含量,根系中乙醇脱氢酶（ADH）和乳酸脱氢酶（LDH）活性增加,乙醇和乳酸含量升高,植株生长受到抑制,而外源腐胺能缓解D-精氨酸的这种作用.说明黄瓜幼苗根系中较高的多胺含量可能有利于缓解低氧胁迫对植株造成的伤害.     

嫁接对铜胁迫下黄瓜幼苗根系多胺代谢的影响

采用营养液栽培法,研究了嫁接(以黑籽南瓜为砧木)对铜胁迫下黄瓜幼苗根系活力及多胺代谢的影响.结果表明:铜胁迫下黄瓜幼苗根系活力下降,电解质渗漏率升高,而嫁接苗的变化幅度显著小于黄瓜自根苗;铜胁迫下黄瓜嫁接植株根系中除游离态腐胺(Put)含量显著低于自根苗外,结合态和束缚态Put、3种形态亚精胺(Spd)和精胺(Spm)含量均显著高于自根苗,嫁接苗根系中游离态Put含量及腐胺/多胺(Put/PAs)显著低于自根苗;铜胁迫下,嫁接苗根系精氨酸脱羧酶(ADC)、鸟氨酸脱羧酶(ODC)和S-腺苷蛋氨酸脱羧酶(SAMDC)活性高于自根苗,而二胺氧化酶(DAO)和多胺氧化酶(PAO)活性显著低于自根苗.表明嫁接黄瓜幼苗根系PAs的合成增加,降解减少,使PAs含量维持在较高水平,从而提高了黄瓜幼苗抗铜胁迫能力.     

外源多胺对低氧胁迫下黄瓜幼苗根系生长及H+-ATP酶和H+-焦磷酸酶活性的影响

采用营养液水培方式,研究了根际低氧胁迫下外源多胺对黄瓜幼苗植株根系生长,内源多胺含量与质膜H -ATP酶、液泡膜H -ATP酶和焦磷酸酶活性的影响.结果表明,根际低氧胁迫显著抑制黄瓜幼苗根系的生长,外源Put(腐胺)和Spd(亚精胺)可缓解低氧胁迫对根系的生长抑制,多胺主要以Spd的形式发挥促进性的生理作用,Put通过转化为Spd发挥作用;低氧胁迫下黄瓜根系内源多胺含量略有提高,外源多胺处理可增加内源多胺的含量;低氧胁迫下外源Put和Spd处理后质膜H -ATP酶活性显著提高,外源多胺对黄瓜根系液胞膜H -ATP酶和H -焦磷酸酶活性没有明显影响,说明低氧胁迫下外源多胺主要通过提高质膜H -ATP酶活性而发挥生理作用.     

外源EBR对NaCl胁迫下燕麦幼苗无机离子吸收、运输和分配的影响

为了探讨外源2,4-表油菜素内酯(2,4-epibrassinolide,EBR)诱导燕麦(Avena sativa L.)幼苗抗盐性的效果及其生理调节机制,以"青引2号"和"加燕2号"燕麦为材料,研究NaCl胁迫下施用外源EBR对燕麦幼苗无机离子吸收、运输和分配的影响。结果表明:100mmol·L-1NaCl胁迫下,"青引2号"和"加燕2号"燕麦幼苗叶片和根系中的Na+、Cl-含量均显著升高,对阳离子的吸收产生了拮抗作用,导致燕麦幼苗叶片和根系中的K+、Ca2+、Mg2+、Mn2+、Fe2+、Zn2+、Cu2+含量显著降低,离子稳态平衡被打破;100 mmol·L-1NaCl胁迫下,施用0.01μmol·L-1外源EBR后,"青引2号"和"加燕2号"燕麦幼苗叶片和根系中的Na+和Cl-含量显著降低,促进了燕麦幼苗根系对K+、Ca2+、Mg2+、Fe2+、Mn2+、Cu2+和Zn2+的吸收,叶片和根系中K+/Na+、Cl-/Na+、Ca2+/Na+、Mg2+/Na+、Fe2+/Na+、Mn2+/Na+、Cu2+/Na+和Zn2+/Na+显著升高,并且有效调控燕麦幼苗体内无机离子的运输比和阳离子的运输选择性比率,离子稳态重新达到平衡状态;说明外源EBR能够缓解NaCl胁迫下Na+和Cl-对燕麦幼苗所造成的离子毒害作用,有效调控燕麦幼苗对无机离子的选择性吸收、运输和分配,对维持燕麦幼苗体内的离子稳态平衡具有正向调控作用。     

外源EBR对NaCl胁迫下燕麦幼苗无机离子吸收、运输和分配的影响

为了探讨外源2,4-表油菜素内酯(2,4-epibrassinolide,EBR)诱导燕麦(Avena sativa L.)幼苗抗盐性的效果及其生理调节机制,以"青引2号"和"加燕2号"燕麦为材料,研究NaCl胁迫下施用外源EBR对燕麦幼苗无机离子吸收、运输和分配的影响。结果表明:100mmol·L-1NaCl胁迫下,"青引2号"和"加燕2号"燕麦幼苗叶片和根系中的Na+、Cl-含量均显著升高,对阳离子的吸收产生了拮抗作用,导致燕麦幼苗叶片和根系中的K+、Ca2+、Mg2+、Mn2+、Fe2+、Zn2+、Cu2+含量显著降低,离子稳态平衡被打破; 100 mmol·L-1NaCl胁迫下,施用0.01μmol·L-1外源EBR后,"青引2号"和"加燕2号"燕麦幼苗叶片和根系中的Na+和Cl-含量显著降低,促进了燕麦幼苗根系对K+、Ca2+、Mg2+、Fe2+、Mn2+、Cu2+和Zn2+的吸收,叶片和根系中K+/Na+、Cl-/Na+、Ca2+/Na+、Mg2+/Na+、Fe2+/Na+、Mn2+/Na+、Cu2+/Na+和Zn2+/Na+显著升高,并且有效调控燕麦幼苗体内无机离子的运输比和阳离子的运输选择性比率,离子稳态重新达到平衡状态;说明外源EBR能够缓解NaCl胁迫下Na+和Cl-对燕麦幼苗所造成的离子毒害作用,有效调控燕麦幼苗对无机离子的选择性吸收、运输和分配,对维持燕麦幼苗体内的离子稳态平衡具有正向调控作用。     

外源腐胺对根际低氧胁迫下黄瓜幼苗多胺和抗氧化系统的影响

采用营养液栽培,研究了外源腐胺(Put)对根际低氧胁迫下黄瓜幼苗体内多胺含量和抗氧化系统的影响.结果显示,低氧胁迫显著刺激了黄瓜幼苗体内活性氧(ROS)和内源多胺含量的增加,提高了抗氧化酶活性;外源Put进一步提高了低氧胁迫下黄瓜幼苗体内多胺的含量和抗氧化酶活性,降低了ROS含量,从而缓解了低氧胁迫的伤害作用;Put合成抑制剂D-精氨酸(D-Arg)不仅显著抑制黄瓜幼苗体内多胺的合成,而且抑制抗氧化酶活性,同时ROS大量积累,进一步抑制黄瓜幼苗的生长;而外源Put可缓解D-Arg的抑制作用;Put转化抑制剂甲基乙二醛-双(脒基腙)(MGBG)和Put降解抑制剂氨基胍(AG)的混合施用造成游离态Put的过量积累,以及亚精胺(Spd)、精胺(Spm)含量和抗氧化酶活性的显著降低,造成ROS大量积累,进一步加重了低氧胁迫对植株的伤害.结果表明,低氧胁迫下外源Put可提高黄瓜幼苗体内游离态Put含量,促进游离态Put向Spd和Spm转化,Spd、Spm含量的增加以及(free-Spd free-Spm)/free-Put比值的升高有利于提高植株抗氧化酶活性,增强清除ROS的能力,降低膜脂过氧化的伤害,从而增强植株的低氧胁迫耐性.     

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.     

Uniform hypothesis of cell behavior--movement, contact inhibition of movement, adhesion, chemotaxis, phagocytosis, pinocytosis, division, contact inhibition of division, fusion.

The cell has been represented as a charged liquid drop. Contrary to the DLVO-theory, the effect of the surface potential upon the value of the interfacial tension of the cell membrane has also been taken into consideration. The cell membrane has visco-elastic properties and its constituents may move against each other. Cell movement is caused by the appearance of a small number of the electrically charged constituents of the cell membrane on the leading edge of the cell. This produces a local decrease in the surface tension and the cell membrane expansion. At the moment of contact between two cells proton transfers occur between the strongly negatively charged microvilli of one cell and the body of the other, analogous to a condenser breakdown. This, through the effect on the surface tension, causes contact inhibition of movement. The distribution of the proton dissociable groups modifies the interaction between the cells (differentiation) and between the cell and the substratum (adhesion). Adsorption of the charged compounds at the surface of the cell membrane, decreasing the surface potential and increasing the surface tension, causes the phenomena of chemotaxis, phagocytosis and pinocytosis. Cell division, considered in the terms of the surface energy, requires an adequate supply of considerable quantities of energy inversely proportional to the surface potential value. In case of a reduction of the distance between the cells, their surface potential and the energetic barrier of the cell division processes increases, and causes contact inhibition of cell division. Due to their high charge, division of neoplastic cells is inhibited much later than division of normal cells, or is completely ininhibited due to geometric conditions. Fusion of the cell membrane in the intra-cellular and intercellular processes is a reverse process in relation to the cell division.     

The effect of malathion,diazinon, and various concentrations of zinc,copper, nickel,lead, iron,and mercury on fish

Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive to diazinon. Long-term exposure to pesticides modified morphology and behavior. The LC50-96 values for Cu, Hg, and Pb were 0.3, 0.16, and 0.44, respectively, for smaller fish and 1.0, 0.77, and 1.33, respectively, for larger fish. Replicate LC50 values for Zn, Ni, and Fe were somewhat variable, and for these metals, the size of the fish seemed to affect response because LC50 values increased as fish size increased. Cooper, Pb, Zn, and Fe residues following exposure to sublethal concentrations of these metals for 15 d were significantly greater in whole juvenile common carp than in controls.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.     

Further studies of the sieve-element plastids of theCaryophyllales includingBarbeuia,Corrigiola, Lyallia,Microtea, Sarcobatus,andTelephium

The sieve-element plastids of 69 species of theCaryophyllales were investigated by transmission electron microscopy. All contained the specific subtype-P3 plastids characterized by a peripheral ring of protein filaments. The presence or absence of an additional central protein crystal and their shape being either polygonal or globular as well as the average sizes of the sieve-element plastids are useful features in the characterization of some families.—Barbeuia contains sieve-element plastids that confirm its placement within thePhytolaccaceae. Lyallia differs fromHectorella by including small starch grains in their sieve-element plastids, which otherwise by their globular crystals negate a closer connection to theCaryophyllaceae. The lack of a central protein crystal in its form-P3fs plastids placesMicrotea best within theChenopodiaceae. Sarcobatus, a so far uncontested member of theChenopodiaceae, contains form-P3cf plastids, i.e., including a central crystal not found elsewhere in this family.Telephium andCorrigiola, shifted back and forth betweenMolluginaceae andCaryophyllaceae, have form-P3cf(s) plastids with a polygonal crystal which favor their placement within theCaryophyllaceae.     

Translocation of radionuclides of Co, Zn, Se, Rb, Y, Tc, and Re into organs of tomato plant via roots

The translocation of the radionuclides of Co, Zn, Se, Rb, Y, Tc, and Re into red and green fruits, flesh, seeds, rind, calyxes, flower, leaves, and stems via the root of the tomato plant at two different growth stages was studied by a multitracer technique. The contents (%/g) of Co, Zn, Se, and Y in the roots were the highest among the organs, but only small amounts of them were translocated into the aerial parts after 5 d cultivation with a multitracer. In contrast, Rb, Tc, and Re showed rapid translocation into the stems and leaves from the root. In the plants cultivated for 95 d with a multitracer, Zn, Se, and Rb distributed in all of the organs, Co in the organs except for flowers, and Y, Tc, and Re in the limited organs. The translocation ratio of the elements for the edible part of the plants cultivated for 95 d decreased in the order of Rb>Zn>Co≈Se>Tc≈Y>Re. The transfer factor of the elements for tomato fruit was determined to be in the range of 10⁻⁵–10⁻². The characteristic translocation behavior of the elements gives us fundamental information on the assessment of pollutant uptake by the tomato plant.     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.