早熟桃果实和种子发育过程中乙烯产生及ACC含量和ACC氧化酶活性的变化(简报)

早熟桃果实在成熟前（授粉后30～48d）产生的乙烯极微,而此阶段种子产生的乙烯则相当高。果实乙烯大量产生前内果皮开裂。种子产生的乙烯可能是启动早熟桃果实成熟的关键性因子。     

双歧杆菌对小鼠肝癌腹水瘤细胞Ca~(2 )-ATPase及糖原磷酸化酶a的影响

采用青春型双歧杆菌菌液与小鼠肝癌腹水瘤细胞 HCa/16 A 3- F相互作用 ,测定其对细胞糖原磷酸化酶 a和微粒体 Ca2 - ATPase活性的影响 ,发现两种酶的活性均明显低于对照组 ,这与细胞内其他一些钙稳态指标的变化相一致。提示双歧杆菌菌液对此腹水瘤钙稳态具有一定的影响 ,可为双歧杆菌的抗肿瘤作用提供一定的依据     

介质Ca~(2 )和La~(3 )对酿酒酵母生长的影响

采用正交实验研究了外加Ｃａ~(２＋)和Ｌａ~(３＋)对酿酒酵母生长的影响。结果表明：外加Ｃａ~(２＋)和Ｌａ~(３＋)对酿酒酵母的生长均有显著的影响,都呈现出低浓度时正效应和高浓度时负效应,当Ｃａ~(２＋)浓度为１ｍｍｏｌ／Ｌ及Ｌａ~(３＋)浓度为１５μｍｏｌ／Ｌ时酿酒酵母生长最好。     

活性氧对外源IAA诱导的ACC合酶活性的影响(英)

本文试图从活性氧的角度阐明外源IAA诱导ACC合酶活性的机制。绿豆 (PhaseolusradiatusL .)幼苗的乙烯产生及ACC合酶活性从萌发的第 5天开始上升 ,到第 10天达到高峰 ,接着下降。 10 μmol/L的外源IAA能明显促进绿豆幼苗乙烯的产生及ACC合酶的活性 ,同时也促进了超氧阴离子自由基 (O-·2 )、过氧化氢 (H2 O2 )的产生。显示外源IAA诱导的ACC合酶的活性与其诱导的活性氧的产生具有某种相关性。外源O-·2 处理能明显提高绿豆幼苗的乙烯产生速率及ACC合酶的活性 ,而外源H2 O2 无论对乙烯产生或ACC合酶的活性均没有明显的作用。外加O-·2 的清除剂SOD对绿豆幼苗乙烯的产生及ACC合酶活性的提高有一定的抑制作用 ,而外源过氧化氢酶却没有明显的作用。为此我们可以得出结论 :外源IAA诱导的绿豆幼苗ACC合酶活性的提高可能是由于其诱导的O-·2 产生的升高引起的 ,这可能也是高等植物中调控乙烯生物合成的机制之一 ;而IAA诱导的H2 O2 产率的升高并不是其诱导ACC合酶活性升高的原因。     

胡萝卜及其愈伤组织细胞质Ca~(2 )水平分析的研究

为测定植物细胞质内[Ca~(2 )]_i,对胡萝卜(Daucus carota var.sativa DC.)原生质体制备介质做了改进,并在正常生理条件下,用温和的、非损伤性的方法将Ca~(2 )荧光指示剂indo-1 K~ 和fura-2 K~ 导入该原生质体,能很好地标记细胞质内的游离Ca~(2 )。在此基础上,用显微荧光光度单波法测定被标记原生质体单个细胞胞质[Ca~(2 )]_i。结果表明:被indo-1 K~ 标记的胡萝卜及其愈伤组织的原生质体[Ca~(2 )]_i分别为88.3nmol/L和263.0nmol/L;fura-2 K~ 标记的分别为99.9nmol/L和255.5nmol/L。由此可见,脱分化的、处在细胞周期中的愈伤组织细胞质中[Ca~(2 )]_i远高于分化了的、处于静息态的胡萝卜细胞。此外,为了确认测量的可靠性,对两种Ca~(2 )荧光指示剂分别做了体外校正,证明其线性相关。     

O2、ACC和CO2对番木瓜ACC氧化酶活性的影响

研究了番木瓜果皮l-氨基环丙烷-l-羧酸(ACC)氧化酶的部分纯化,底物(O2和ACC)浓度、辅助因子(CO2和Fe2+)和抑制剂(Co2+和α-氨基异丁酸)对体外乙烯产生速率的影响.通过DEAE-Sepharose和Phenyl-Sepharose柱层析后,番木瓜果皮ACC氧化酶被纯化了19.5倍.在乙烯产生中,ACC氧化酶对O2的Km值主要取决于ACC的浓度,随着ACC水平的增加而下降;当O2的浓度增加时,酶对ACC的Km值降低.CO2显著地增加酶的活性以及对O2和ACC的Km值.Fe2+提高酶的活性,Co2+抑制酶的活性;Fe2+能够拮抗Co2+对酶活性的抑制作用.这些动力学资料表明ACC氧化酶遵循一种顺序结合机制,首先与02结合,然后与ACC结合.     

Ca~(2 )对叶绿体中超氧物自由基产生以及由ACC形成乙烯的影响

高浓度Ca~(2 )(0.1 mol/L)使叶绿体产生O_2~ 的能力下降,旋转相关时间(τ_c)增大34.3％,即膜的流动性降低,并抑制ACC形成乙烯;衰老时细胞内的Ca~(2 )作用却与此相反;O_2~ 的生成与乙烯的产量成正相关(r=0.941)。EGTA,吩噻嗪和W_7等加入到叶绿体反应体系中,可使O_2~ 的产量下降,ACC形成乙烯减少;相反,亚油酸作为Ca~(2 )载体,却使之明显升高,但亚油酸本身产生乙烯的量比ACC少得多。因此推测:高浓度Ca~(2 )可能影响叶绿体膜的状态,从而影响EFE的构象或者减少O_2~ 的生成,抑制ACC的转化,衰老时细胞内的Ca~(2 )可启动钙信使系统,使O_2~ 的产量升高,而其中膜脂过氧化是衰老的中心环节,因此O_2~ 的升高可能是诱发衰老启动的重要因素。     

1,25-(OH)_2D_3诱导HL-60细胞分化后胞液Ca~(2+)浓度、磷酸化酶a和微粒体Ca~(2+)-ATP酶活性的改变

1,25-(OH)_2D_3对HL-60细胞具有促分化作用。本文报道了1,25-(OH)_2D_3在促进HL-60细胞分化前后胞液Ca~(2+)浓度、磷酸化酶a和微粒体Ca~(2+)-ATP酶活性的改变。结果表明,1,25-(OH)_2D_3加入HL-60细胞培养液后72小时,细胞NBT染色阳性率高于70％,形态向正常分化的细胞转化。同对,胞液Ca~(2+)浓度和微粒体Ca~(2+)-ATP酶活性明显降低,而磷酸化酶a活性显著升高。结果提示,在1,25-(OH)2_D_3作用下,HL-60细胞不仅杀菌功能增强,细胞内胞液Ca~(2+)浓度趋向正常,与钙恒稳有关的酶活性也同样发生改变。即1,25-(OH)_2D_3对HL-60细胞的诱导作用伴有钙恒稳的改变。这些变化与DMSO的作用相同。     

O2、ACC和CO2对番木瓜ACC氧化酶活性的影响（英文）

研究了番木瓜果皮l-氨基环丙烷-l-羧酸(ACC)氧化酶的部分纯化,底物(O2和ACC)浓度、辅助因子(CO2和Fe2+)和抑制剂(Co2+和α-氨基异丁酸)对体外乙烯产生速率的影响.通过DEAE-Sepharose和Phenyl-Sepharose柱层析后,番木瓜果皮ACC氧化酶被纯化了19.5倍.在乙烯产生中,ACC氧化酶对O2的Km值主要取决于ACC的浓度,随着ACC水平的增加而下降;当O2的浓度增加时,酶对ACC的Km值降低.CO2显著地增加酶的活性以及对O2和ACC的Km值.Fe2+提高酶的活性,Co2+抑制酶的活性;Fe2+能够拮抗Co2+对酶活性的抑制作用.这些动力学资料表明ACC氧化酶遵循一种顺序结合机制,首先与02结合,然后与ACC结合.     

肌醇磷脂信号途径参与胞外钙调素启动花粉萌发和花粉管伸长

高等植物有性生殖是植物发育生物学研究的重要内容之一,而作为雄配子体的花粉在雌蕊柱头上萌发及花粉管在花柱内的持续生长是有性生殖实现的关键。已有许多研究表明Ca2 在花粉萌发和花粉管生长过程中起重要作用。最近,我室在多年细胞外钙调素（calinodulin,CaM）存在。性质及生物学功能研究（孙大业等1995;Sun等1994,1995;Tang等1996）的基础上,通过不过膜的大分子CaM拈抗剂或抗体并结合恢复实验证实细胞外CaM对花粉的萌发和花粉管的伸长具有启动作用（马力耕和孙大业1996）,并发现G蛋白、质膜Caz”通道及胞内依赖Caz”的蛋白…     

Intrasynaptosomal Free Calcium Concentration During Rat Brain Development: Effects of Hypoxia, Aglycaemia, and Ischaemia

Abstract: The effects of hypoxia, aglycaemia, and hypoxia-aglycaemia on intrasynaptosomal free Ca²⁺ concentration ([Ca²⁺]_i) have been investigated in rat brain synaptosomes prepared from animals aged 5, 10, 15, 20, 25, and 60 days. After 60 min of hypoxia there was no significant difference, when compared with controls, in basal [Ca²⁺]_i or [Ca²⁺]_i following depolarisation in all of the ages studied. Following 60 min of aglycaemia there was no significant difference from controls in [Ca²⁺]_i of synaptosomes prepared from pups of ≤20 days, although a significant rise in [Ca²⁺]_i was seen in preparations from animals >20 days old. Sixty minutes of hypoxia-aglycaemia led to a significant rise in [Ca²⁺]_i only in preparations from animals 15–60 days old. With both aglycaemia and hypoxia-aglycaemia a progressive increase in the magnitude of the rise in [Ca²⁺]_i was seen with development. These data suggest increases in [Ca²⁺]_i in adult nerve terminals following prolonged aglycaemia and hypoxia-aglycaemia but no change following prolonged hypoxia. In contrast, no significant changes in [Ca²⁺]_i values were apparent in neonatal nerve terminals under any of these conditions. In control synaptosomes with glucose and oxygen freely available, a decrease in resting and depolarised [Ca²⁺]_i during development was seen, suggesting a change in calcium homeostasis within the nerve terminal as the brain develops. It is suggested that the mechanism underlying the relative resistance to ischaemic damage of neonatal brain as compared with adult brain may be related to the regulation of calcium at the nerve ending.     

钙对金针菇生长发育的影响

研究了CaCO3粉末对金针菇(Flammulina velutipes)生长发育的影响及子实体的富钙作用。结果表明,钙能显著刺激金针菇菌丝体和子实体的生长,缩短出菇时间,提高产量和子实体含钙量。这些生理生化变化与钙浓度密切相关,低质量分数(0~5%)和高质量分数(5.5~10%)的CaCO3粉末造成了相似的变化。初步分析认为,这可能与金针菇细胞内存在两种不同的钙信号转导途径有关。     

干旱胁迫下外源氯化钙、水杨酸和一氧化氮对石蒜抗旱性的影响

通过盆栽试验,研究了外源氯化钙（CaCl2）、水杨酸（SA）和NO供体硝普钠（SNP）处理对干旱胁迫下石蒜抗旱性的影响。结果表明,较低浓度的CaCl2对石蒜抗旱性的影响不显著,而随着CaCl2预处理浓度的提高,石蒜的抗旱效果显著增强。较低浓度SA和sNP可显著提高石蒜的抗旱性,而高浓度则会发生毒害作用。利用模糊隶属函数法综合评价渗透调节物质、膜系统和抗氧化酶活性多项指标可以得出,喷施10mmol·L—CaCl2、2mmol-L。SA和0．5mmol·L-1 SNP对石蒜抗旱性的提高具有显著效果。     

钙对水杨酸诱导番茄叶片灰霉病抗性及防御酶活性的影响

以番茄‘L402’品种幼苗为试材,经水杨酸(SA)诱导处理后接种灰霉病菌,再进行外源Ca2+、Ca2+螯合剂和Ca2+抑制剂处理,分析Ca2+和SA处理番茄叶片对灰霉病抗性和主要防御酶系活性的变化,探讨Ca2+和SA对番茄诱导抗病性的影响。结果显示:(1)外源SA可显著提高番茄诱导叶和非诱导叶抗灰霉病能力,Ca2+能进一步增强SA诱导的抗病能力;而Ca2+螯合剂EGTA和质膜钙通道抑制剂LaCl3则不同程度地抑制了SA诱导的番茄灰霉病抗性。(2)外源SA能提高番茄诱导叶和非诱导叶中苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)活性,外源Ca2+亦进一步增强了SA诱导的上述防御酶活性,但缺钙处理则不同程度降低这些防御酶活性。(3)外源补充Ca2+及不同缺钙处理对SA诱导的过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性未发现规律性影响。研究表明,钙对SA诱导番茄抗灰霉病性的增强效应,可能与其提高SA诱导番茄叶片中PAL、PPO和POD等防御酶活性有关。     

The Effects of N-1-Naphthylphthalamic Acid and (2-Chloroethyl)-phosphonic Acid on the Gravity-induced Lateral Transport of 2, 4-Dichlorophenoxyacetic Acid

N-1-Naphthylphthalamic acid markedly reduced the polar lateralmovement of 2, 4-D-[1-¹⁴C] induced by gravity in horizontalsegments of Helianthus hypocotyl. The pattern of this inhibitionresembled the inhibition of basipetal polar transport, suggestingthat both polar movements are operated by essentially the samephysiological mechanisms though there are indications of sensitivitydifferences between the two systems. Ethrel pretreatment of segments, though inhibiting the basipetaltransport of 2, 4-D by 33 per cent over the concentration range0.2 to 2.0 per cent, has little significant effect on gravity-inducedlateral polarity of movement, suggesting that ethylene doesnot act directly on the auxin transport system.     

钙处理对桃冷藏期间呼吸速率和乙烯释放以及与褐变相关酶活性的影响

桃冷藏期间3?Cl2处理的效果最好,呼吸速率、乙烯释放量、过氧化物酶(POD)和多酚氧化酶(PPO)活性均显著下降(P≤0.05).     

The Effects of 2:4-Dichlorophenoxyacetic Acid, 2:3:5-Tri-Iodobenzoic Acid, and Thiourea on the Vegetative and Reproductive Growth of Avena sativa

The effects of 2:4-dichlorophenoxyacetic acid (2:4-D), 2:3:s-tri-iodobenzoicacid (TIBA), and thiourea on the growth of Avena sativa havebeen studied in relation to subsequent leaf development, tillerproduction, and apical growth of the seedlings. Treatments with2:4-D and TIBA depressed the emergence of each successive shootingleaf, but thiourea, at the concentration used, proved to belethal. Subsequent observations on the tillering capacity ofthe seedlings show that treatment with 2I4-D significantly increasesthe rate of tiller production, but that TIBA fails to do so. Longitudinal sections through the apices of the treated seedlingsshow that both treatments have inhibited the development ofthe apex. 2I4-D inhibition is the greater. In the concentrationsapplied, neither treatment caused any obvious abnormalitiesin respect of mature leaves.     

丙二醛对大鼠海马神经元结构的破坏和钙离子稳态的影响

脂质过氧化中间产物丙二醛(Malondialdehyde,MDA)在生物体内表现了广泛的生物毒性,MDA也是机体过度训练和运动性疲劳的重要生理指标.采用光学显微镜和透射式电子显微镜观察不同浓度MDA作用后海马神经元形态和超微结构的变化,并采用荧光分光光度法测定原代培养的海马神经元中Ca2+-ATPase活性的变化和胞质游离钙离子水平的变化,探讨MDA对海马神经元形态和结构上的破坏及神经元钙离子稳态的影响.在光镜下可观察到MDA作用下神经元突触变短,胞体肿胀,出现细胞死亡或凋亡的形态特征;在电镜下可观察到线粒体结构的明显破坏,内膜上的嵴颗粒减少或消失;同时MDA还通过抑制质膜Ca2+-ATPase的活性和其它的途径,破坏神经元胞质游离Ca2+稳态.结果表明,MDA可通过破坏海马神经元的结构和影响胞质中钙离子稳态,破坏神经元的生理功能,在机体运动性中枢疲劳形成中可能发挥重要作用.     

Synthesis and biological evaluation of 5-fatty-acylamido-1, 3, 4-thiadiazole-2-thioglycosides

In the present study, the synthesis of 1, 3, 4-thiadiazole-based thioglycosides were accomplished in good yields with employing a convergent synthetic route. The starting material 5-amino-1, 3, 4-thiadiazole-2-thiol and followed by a series of 5-fatty-acylamido-1, 3, 4-thiadiazole-2-thiols (4a–4j) were synthesized with different fatty acid chlorides. The glycosylation of compounds 4a–4j were achieved with trichloroacetimidate methodology. Antimicrobial and cytotoxicity activities of title compounds were evaluated. Among the entire compounds lauric acid and myristic acid derivatives showed good and moderate antimicrobial activity. In case of cytotoxicity results of compounds 8a–8j and 9a–9j, the acetate protected short chain (C6:0, C8:0, C10:0) compounds and the free hydroxyl long chain saturated (C16:0, C18:0) and unsaturated (C18:1, C22:1) compounds exhibited good activity against different cancer cell lines. Further, the free hydroxyl compounds 9a, 9c–9j did not show any toxicity towards normal CHO-K1 cell line whereas acylated compounds 8a–8j exhibited toxicity.