Se和环境中富里酸对小麦种子发芽的影响及其生理特性

利用种子发芽实验研究了亚硒酸钠（ＮＶ２ＳｅＯ３）和从土壤中提取的富里酸（Ｆｕｌｖｉｃ ａｃｉｄ, ＦＡ）对小麦种子发芽和生长的影响,以及 ＦＡ对亚硒酸钠毒性的抑制作用．结果表 明．ＦＡ和低浓度Ｎａ２ＳｅＯ３对种子发芽及发芽后的生长有促进作用,高浓度 Ｎａ２ＳｅＯ３明显 降低种子发芽率、种子活力、α－淀粉酶活性及幼苗的生长,ＦＡ对亚硒酸钠的毒性有一定的 抑制作用．     

秦巴山区富硒蛹虫草有效成分及硒存在形态分析

为探究秦巴山区富硒蛹虫草有效成分及硒存在形态,以秦巴山区蛹虫草CM-1518为研究对象,研究不同质量分数亚硒酸钠(0～500 mg/kg)对蛹虫草生长发育的影响,并对其有效成分及硒存在形态进行分析。试验结果表明当亚硒酸钠质量分数为100 mg/kg时,蛹虫草鲜质量最高,为293.41 g/盒。当亚硒酸钠质量分数为200 mg/kg时,虫草素、虫草酸含量最高,分别为1.06 mg/g和2.10 mg/g,表明硒与虫草素和虫草酸可协同增效,但虫草多糖含量变化规律不明显,亚硒酸钠的添加不利于腺苷的合成积累。经计算,富硒蛹虫草中有机硒所占百分比均高达99.9%,低浓度的亚硒酸钠可促进可溶性蛋白和可溶性多糖中硒的合成,但高浓度的硒却降低其合成,且富硒蛹虫草中可溶性多糖中硒含量高于可溶性蛋白硒含量。试验表明适宜浓度的亚硒酸钠可促进蛹虫草生长发育及有效成分合成积累。     

亚硒酸钠对小麦幼苗中谷胱甘肽过氧化物酶和谷胱甘肽转硫酶活性以及谷胱甘肽含量的影响

用1.0 mg·L-1的亚硒酸钠根施小麦幼苗,测定亚硒酸钠对谷胱甘肽过氧化物酶和谷胱甘肽转硫酶活性以及还原性谷胱甘肽含量的结果表明,外源亚硒酸钠对麦苗地上部的谷胱甘肽过氧化物酶和谷胱甘肽转硫酶活性均有诱导作用,使麦苗体内的谷胱甘肽含量水平增加.     

培养方式对富硒产朊假丝酵母性能的影响

在摇瓶和5 L发酵罐水平上分别考察亚硒酸钠浓度及其添加方式对高性能(高有机硒含量和高谷胱甘肽含量)富硒产朊假丝酵母制备的影响.结果表明:亚硒酸钠添加质量浓度为15 mg/L时,产朊假丝酵母具有较好的富硒效果,但一次性添加对酵母细胞有较大的毒害作用.采用分批次添加亚硒酸钠的方法获得了较好的制备高性能富硒产朊假丝酵母的培养方式:发酵起始添加L-蛋氨酸10 mmol/L,并在发酵过程的12和15 h分别添加亚硒酸钠10和5 mg/L.在此培养方式下,产朊假丝酵母胞内谷胱甘肽和有机硒含量分别达到172.3 mg/L和1194 μg/g.     

卫星灵芝液体发酵富集硒锌的研究

研究不同浓度的硒、锌对卫星灵芝菌丝体生长的影响,初步探讨卫星灵芝菌丝体生物富集硒、锌的效应。采用平板培养法及液体发酵法研究锌、硒对卫星灵芝菌丝体生长的影响及富集效应。培养基中不同浓度的亚硒酸钠对菌丝体生长均具有不同程度的抑制作用,但灵芝菌丝体的富硒量随着硒浓度的增加而提高,当亚硒酸钠浓度为40 mg/L时,菌丝体中的生物量、富硒量及富硒转化率最高,分别为1.54%、2 131.55 mg/kg、32.91%;培养基中硫酸锌浓度低于150 mg/L的范围内对卫星灵芝菌丝体生长有明显的促进作用,硫酸锌浓度为60 mg/L时菌丝体中的锌含量和富锌转化率最高,分别为1 142.91 mg/kg、1.76%。培养基中同时添加40 mg/L的亚硒酸钠和60 mg/L硫酸锌,菌丝体生长量1.60%,富硒量301.85 mg/kg,富硒率4.84%;富锌量为540.41 mg/kg,富锌率为5.72%。     

真姬菇液体发酵培养基筛选及硒富集条件优化

以真姬菇菌种为材料,采用液体摇瓶培养进行最适发酵培养基的优化,并探讨不同浓度亚硒酸钠和甘油的富硒效果。结果表明:真姬菇菌种最优液体发酵培养基为:马铃薯20%,麦麸滤液3%,可溶性淀粉3%,酵母粉0.15%,硫酸镁0.1%,磷酸二氢钾0.2%,最大生物量可达13.2 g/L;亚硒酸钠对菌丝生长有抑制作用,但可促进菌丝富硒,当其浓度为40μg/mL时,菌丝体的硒含量最大,达1.75μg/g,总体硒富集含量可达5.8μg/L发酵液;甘油对亚硒酸钠的总富硒含量有促进作用,当甘油浓度为50μg/mL时,菌丝总体硒富集含量最大,可达26.7μg/L发酵液。     

钝顶螺旋藻富硒培养条件的优化

硒是人和动物必需的微量元素 ,补硒可以防治多种疾病。有机硒具有低毒、高生物利用度的优点 ,目前主要寄希望于生物转化的途径来获得有机硒[1 ] 。植物对硒的生物有机化作用已有综述[2 ] ,并开发有富硒酵母[3 ] 、富硒菇类[4] 、富硒大蒜、富硒黄芪、富硒西洋参、富硒麦芽、富硒茶以及富硒鸡蛋、富硒牛奶等[5] 。螺旋藻是一种很有开发利用前景的藻类 ,但其含硒量极微 ,实验报道富硒螺旋藻对60 Ｃｏ γ射线胸部照射大鼠诱发肺炎和早期肺、肝纤维增生有防治作用[6] 。在培养液中添加亚硒酸钠可以实现藻类对硒的富集和转化 ,而且螺旋藻对无机硒…     

一株假单胞菌(Pseudomonas alcaliphila MBR)好氧还原亚硒酸钠为红色单质硒

【目的】本实验室保藏的一株异化硝酸盐还原菌(Pseudomonas alcaliphila MBR),其能够在好氧环境下以有机碳源为电子供体,把易溶解、高毒性亚硒酸钠还原成为红色单质硒,本文对该菌株还原亚硒酸盐的特征进行了研究。【结果】结果表明该菌株可以在pH为6-11环境中生长,对亚硒酸钠有较强抗性,其MIC(minimal inhibitory concentration)可高达50 mmol/L。在5天时间内,菌体以柠檬酸钠为电子供体,把2 mmol/L亚硒酸钠完全还原为红色单质硒并主要积累于胞外。硝酸盐和还原型谷胱甘肽对菌体还原亚硒酸钠具有促进作用,初步确定菌体对亚硒酸钠的还原是细胞膜或细胞质中的某些物质催化的结果。【结论】本项研究为应用Pseudomonas alcaliphila MBR于生物反应器提供了重要基础。     

亚硒酸钠对大鼠晶体上皮细胞αA晶体蛋白基因转录的影响

在体外观察了亚硒酸钠（Ｎａ２ＳｅＯ３）作用于大鼠晶体上皮细胞（ＲＬＥｃｅｌｌｓ）而引起其晶体蛋白基因转录的改变,对不同浓度的硒在体外对αＡ晶体蛋白基因转录的影响作了初步的研究,结果发现,随着亚硒酸钠浓度的升高,αＡ基因的转录下降;而当亚硒酸钠浓度升至５×１０＾－５ｍｏｌ／Ｌ时,αＡ基因的转录又呈反跳性回升,提示硒在致障过程中对晶体蛋白基因转录的影响作用不可忽视。同时αＡ晶体蛋白在晶体细胞内,至少应     

高富硒酵母的筛选及富硒强化研究

富硒酵母在医学保健和制药产业中有着重要的应用,高富硒酵母是富硒酵母产品开发的基础。以新疆富硒土壤为样品来源,通过马丁培养基的初筛和富硒能力的复筛,筛选到一株富硒量相对较高的黏红酵母菌株Rhodotorula glutinis X-20。优化了菌株的富硒培养条件,结果显示,利用2%甘油为碳源可显著提高酵母中硒的累积,培养12 h时添加50μg/m L的亚硒酸钠能够保证酵母较高的硒累积量和生物量,添加0.4 mmol/L的磷酸盐可以有效地促进硒的转运和累积,最终使Rhodotorula glutinis X-20富硒量达到5 009μg/g。     

黄腐酸引发软骨细胞产生过氧化氢及硒的抑制作用

为探讨黄腐酸（FA）能否直接刺激软骨细胞产生活性氧以及硒能否抑制由此产生的活性氧,采用二氯荧光素双酯（DCFH－DA）作为软骨细胞产生过氧化氢的探针,用流式细胞技术定量地检测了在FA作用下软骨细胞产生的过氧化氢,并同时检测了硒存在时的过氧化氢含量．发现FA不但能够刺激软骨细胞产生过氧化氢（P＜0．05）,并与FA浓度相关,随FA浓度增大,产生过氧化氢增多,当FA浓度为100mg／L时软骨细胞产生过氧化氢达到最大,之后再增大FA浓度,过氧化氢的产生量减少;硒的存在对FA刺激软骨细胞产生过氧化氢有抑制作用．     

Pathway of cytotoxicity induced by folic acid modified selenium nanoparticles in MCF-7 cells

Selenium nanoparticles (Se NPs) have been recognized as promising materials for biomedical applications. To prepare Se NPs which contained cancer targeting methods and to clarify the cellular localization and cytotoxicity mechanisms of these Se NPs against cancer cells, folic acid protected/modified selenium nanoparticles (FA–Se NPs) were first prepared by a one-step method. Some morphologic and spectroscopic methods were obtained to prove the successfully formation of FA–Se NPs while free folate competitive inhibition assay, microscope, and several biological methods were used to determine the in vitro uptake, subcellular localization, and cytotoxicity mechanism of FA–Se NPs in MCF-7 cells. The results indicated that the 70-nm FA–Se NPs were internalized by MCF-7 cells through folate receptor-mediated endocytosis and targeted to mitochondria located regions through endocytic vesicles transporting. Then, the FA–Se NPs entered into mitochondria; triggered the mitochondria-dependent apoptosis of MCF-7 cells which involved oxidative stress, Ca²+ stress changes, and mitochondrial dysfunction; and finally caused the damage of mitochondria. FA–Se NPs released from broken mitochondria were transported into nucleus and further into nucleolus which then induced MCF-7 cell cycle arrest. In addition, FA–Se NPs could induce cytoskeleton disorganization and induce MCF-7 cell membrane morphology alterations. These results collectively suggested that FA–Se NPs could be served as potential therapeutic agents and organelle-targeted drug carriers in cancer therapy.     

GENETICS OF FLUCTUATING ASYMMETRY: A DEVELOPMENTAL MODEL OF DEVELOPMENTAL INSTABILITY

Although numerous studies have found that fluctuating asymmetry (FA) can have a heritable component, the genetic and developmental basis of FA is poorly understood. We used a developmental model of a trait, according to a diffusion-threshold process, whose parameters are under genetic control. We added a small amount of random variation to the parameter values of this model to simulate developmental noise. As a result of the nonlinearity of the model, different genotypes differed in their sensitivity to developmental noise, even though the noise is completely random and independent of the genotype. The heritable component of FA can thus be understood as genetically modulated expression of variation that is itself entirely nongenetic. The loci responsible for this genetic variation of FA are the same that affect the left/right mean of the trait, showing that genetic variation for FA does not require genes that specifically control FA. Furthermore, the model offers alternative explanations for phenomena widely discussed in the literature on FA, for instance, the correlations between FA and heterozygosity and between FA and trait size. The model underscores the importance of dominance and epistasis, and therefore unites the study of FA with the classical theory of quantitative genetics.     

EFFECTS OF SINGLE AND MULTIPLE EXPOSURES OF FERULIC ACID ON THE VEGETATIVE AND REPRODUCTIVE GROWTH OF PHASEOLUS VULGARIS BBL-290

Phaseolus vulgaris BBL-290 plants were grown in growth chambers in the Southeastern Plant Environment Laboratory and exposed to either single (at seedling, flower, or podfill) or multiple (biweekly or weekly) treatments of ferulic acid (FA). In the first experiment, plants were harvested one week after FA treatment (0, 1.0, 2.0 mM) and at final harvest (56 days old). FA delayed leaf expansion during the seedling and flowering stages. The total plant leaf area and the plant dry weight of plants treated with 1.0 and 2.0 mM FA as seedlings were reduced one week after treatment by 38–48%. The total plant leaf area and the plant dry weight of plants treated at flowering with 2.0 mM FA were reduced by 25% one week after treatment. Treatment with 2.0 mM FA at podfill caused the senescence and abscission of older leaves and reduced total plant leaf area, plant dry weight and mean pod dry weight by 54, 40, and 48%, respectively, one week after treatment. The plants treated at the seedling and flowering stages recovered by final harvest. In a subsequent experiment, FA (0, 0.50, 1.0, 1.5 mM) reduced total plant leaf area at the seedling and flowering stages but not at podfill. The youngest expanding leaves were most sensitive to FA at flowering. The leaf area of these leaves was reduced by 35 and 25%, one and two weeks after treatment, respectively. Their absolute growth rates were reduced from 31 to 56% one week after treatment at flowering. Their relative growth rates were reduced by 50% one week after treatment. Growth rates then recovered within two weeks after treatment. In the final experiment, biweekly exposures of FA (0.25, 0.50, 0.75, 1.0) reduced total plant leaf area but did not affect any other growth parameters. Weekly exposures of FA (0.25, 0.50, 0.75, 1.0) reduced total plant leaf area up to 34%, absolute growth rate up to 58%, leaf number up to 31% and pod number up to 58%. As the frequency of exposure to FA increased, the concentration necessary to affect bean plant growth and development decreased.     

湖北省豆类植物种子硒含量的测定及赋存状态的研究

硒是人类必需的微量元素之一。我们对湖北省豆类植物种子的硒含量进行测定并对硒的赋存状态进行了研究。结果显示:大豆具有较强的富硒能力;大豆硒的赋存形态是含硒蛋白质,主要存在于白蛋白和球蛋白中;高硒地区的大豆含硒量比一般地区高近100倍。     

富硒生物样品中硒的价态和形态分析

本文利用2,3—二氨基萘(DAN)荧光法测定了富硒玉米粉、硒酵母蛋白等样品中四价硒、六价硒、有机硒含量及总硒量。进一步验证了差减法测定不同价态硒含量的实验方法     

ESTIMATING THE HERITABILITY OF FLUCTUATING ASYMMETRY IN FIELD DROSOPHILA

Some studies have found intermediate heritabilities for fluctuating asymmetry (FA) in traits, but almost all of these are flawed and/or based on laboratory experiments. We therefore tested if there was heritable variation for FA in bristle and wing traits in three field collections of Drosophila melanogaster by rearing F₁s from field flies under laboratory conditions. One of the collections was reared to the F₂ generation in the laboratory to compare heritability estimates from the laboratory with those from the field-laboratory comparison. Trait means indicated an increase in size under laboratory rearing. FAs increased in one collection, decreased in another collection, and showed no changes in the third collection under laboratory rearing. FAs from the collections tended to converge under laboratory conditions. Morphological traits were heritable under field conditions. However, FA was not significantly heritable for any of the individual traits or when FA was determined by combining traits. Comparisons of the two laboratory generations showed that FA heritability was low under laboratory conditions, in contrast to the morphological traits themselves. These findings suggest a very low heritability for FA in field and laboratory Drosophila. FA in bristle and wing traits may therefore be a poor indicator of genetic quality in Drosophila.     

饲料中添加高剂量有机硒和无机硒对异育银鲫生长性能、组织硒蓄积和血液生化指标的影响

为探究饲料中高剂量的有机硒和无机硒对异育银鲫(Carassius auratus gibelio var. CAS V)的生长性能、硒蓄积和血浆生化指标等方面的影响,以硒代蛋氨酸(有机硒)和亚硒酸钠(无机硒)作为不同类型的硒源,初始体重为(62.95±0.23) g异育银鲫为研究对象,进行了为期90d的养殖实验。实验结果表明,饲料中添加0、10和20 mg/kg的有机硒和无机硒对异育银鲫的存活和饲料干物质的表观消化率无显著影响;有机硒处理组硒的表观消化率随饲料有机硒的添加量增加而显著升高(P<0.05);饲料中添加无机硒对硒消化率无显影响(P>0.05)。在饲料中添加有机硒可以提高异育银鲫的生长(P<0.05),在20 mg/kg处理组中达到最高(P<0.05);而饲料中添加10 mg/kg无机硒处理组未显著改变异育银鲫的特定生长率(P>0.05),但高浓度的无机硒则显著降低了其特定生长率(P<0.05)。饲料中添加有机硒显著降低了异育银鲫的肝体比,添加10 mg/kg无机硒显著降低异育银鲫的肝体比(P<0.05);饲料中添加有机硒和无机硒对异...     

饲料硒和维生素E对大鼠机体抗氧化能力的影响

 用克山病病区粮配成基础低硒饲料,补充硒和/或维生素E组成四种不同水平的饲料,饲喂雄性断乳大鼠,观察其对机体抗氧化能力的影响。评价指标是用抗坏血酸诱发的红细胞溶血率、被O~-_2(超氧阴离子)氧化的血红蛋白量和组织中的TBA值。动物饲养13周后,自尾静脉取血,测定溶血率和血红蛋白被氧化的百分率,和全血SeGSHPx(含硒谷胱甘肽过氧化物酶)活力。15周后将动物断头杀死,立即取出心脏和肝脏测定SeGSHPx活力和TBA值。结果表明在克山病病区粮的饲料中补充硒或维生素E,或者二者同时补充均明显提高组织中的SeGSHPx活力和降低组织中的TBA值。不论在硒缺乏时或硒充足时,饲料中补充维生素E显著降低抗坏血酸诱发的红细胞溶血率,对O~-_2氧化血红蛋白无保护作用。在维生素E缺乏时,仅补充硒对溶血无作用。不论饲料中维生素E缺乏或者充足,补充硒对O~-_1氧化血红蛋白均有显著保护作用。     

黄腐酸和汪平酸对小麦种子萌发与幼苗生长及绿豆下胚轴生根的影响

用黄腐酸和汪平酸浸种后,对于小麦种子萌发无明显影响。用不同浓度的黄腐酸和汪平酸溶液培养小麦幼苗,发现适当浓度时对于幼苗及根系生长与分化有促进作用,高浓度则表现为抑制作用。10ppm黄腐酸和50ppm汪平酸可显著增加去根绿豆下胚轴再生根数,而且在一定的浓度范围内,随着浓度的增高,根数不断增加而根长却逐渐减短。