磷饥饿时番茄幼苗根系质膜H+-ATP酶活性

磷饥饿提高了番茄幼苗质膜H+-ATP酶活性并促进了番茄幼苗根部的H+分泌。动力学分析表明,磷饥饿使番茄幼苗根部质膜H+-ATP酶的Km值明显降低,亦即提高了该酶对其底物的亲和力,但对该酶的Vmax影响不大。另外,磷饥饿并不改变ATP酶的最适pH值(最适pH值为6.5)。钒酸盐显著抑制番茄幼苗根部质膜ATP酶的活性以及H+分泌,也显著抑制番茄幼苗的Pi吸收。与对照相比,上述抑制作用在饥饿处理的植物中表现得更强。以上结果表明,磷饥饿时高亲和性Pi传递系统的诱导很可能包含质膜H+-ATP酶的参与。     

磷酸饥饿对番茄幼苗生长状况及其磷吸收的影响

本文就磷酸饥饿对番茄幼苗生长状况及共磷吸收的影响进行了研究。结果表明,磷酸饥饿时,番茄幼苗的平均高度下降,而主根的长度却明显长于对照。磷酸饥饿初期对番茄幼苗鲜重累积影响不大,但随着饥饿的继续,受胁迫苗的鲜重累积与对照间的差异加大并且变得明显低于对照。     

磷饥饿时番茄幼苗根系质膜H+-ATP酶活性 的变化与磷吸收的关系

磷饥饿提高了番茄幼苗质膜H     

磷饥饿时番茄幼苗根系质膜H^＋—ATP酶活性的变化与磷吸收的关系

磷饥饿提高了番茄幼苗质膜H^ -ATP酶活性并促进了番茄幼苗根部的H^＋分泌和。动力学分析表明,磷饥饿使番茄功苗根部质膜H^ -ATP酶的K m值明显降低,亦即提高了该酶对其底物的亲和力,但对该酶的Vmax影响不大。另外,磷饥饿并不改变ATP酶的最适pH值（最适pH值为6.5）。钡酸盐显著抑制番茄幼苗根部质膜ATP酶的活性以及H^＋分泌,也显著抑制番茄幼苗的Pi吸收。与对照相比,上述抑制作用在饥饿处理的植物中表现得更强,以上结果表明,磷饥饿时高亲和性Pi传递系统的诱导很可能包含质膜H^ -ATP酶的参与。     

氮素形态对番茄根系液泡膜焦磷酸酶活性的影响

采用超速梯度离心提取液泡膜微囊,研究硝态氮和铵态氮供应情况下番茄（Lycopersicon esculentum L.)根系液泡膜焦磷酸酶活性的变化。结果表明：供应铵态氮番茄根系专一性液泡膜焦磷酸酶活性比供应硝态氮的高37．7％;供应铵态氮根系液泡膜焦磷酸酶转运质子活力也明显高于供应硝态氮根系。Western blot结果表明,供应铵态氮根系液泡膜焦磷酸酶蛋白表达量也明显增加。     

TheRelati磷饥饿时番茄幼苗根系质膜H~ - ATP酶活性的变化与磷吸收的关系(英文)

磷饥饿提高了番茄幼苗质膜H ATP酶活性并促进了番茄幼苗根部的H 分泌。动力学分析表明 ,磷饥饿使番茄幼苗根部质膜H ATP酶的Km 值明显降低 ,亦即提高了该酶对其底物的亲和力 ,但对该酶的Vmax影响不大。另外 ,磷饥饿并不改变ATP酶的最适 pH值 (最适 pH值为 6.5)。钒酸盐显著抑制番茄幼苗根部质膜ATP酶的活性以及H 分泌 ,也显著抑制番茄幼苗的Pi吸收。与对照相比 ,上述抑制作用在饥饿处理的植物中表现得更强。以上结果表明 ,磷饥饿时高亲和性Pi传递系统的诱导很可能包含质膜H ATP酶的参与。     

大豆液泡膜H~+-ATPase泵质子活性的研究

研究了大豆液泡膜Ｈ＋－ＡＴＰａｓｅ泵质子特性。液泡膜Ｈ＋－ＡＴＰａｓｅ泵质子活性受ＮＥＭ、ＮＢＤ－Ｃｌ、ＤＣＣＤ和ＮＯ３－的抑制。泵质子活性由二价阳离子启动,其有效性依次为Ｆｅ２＋＞Ｍｇ２＋＞Ｍｎ２＋,它以ＡＴＰ为最适底物,ＡＤＰ为竞争性抑制剂;最适ｐＨ为７．０,最适温度为５０°Ｃ。     

磷饥饿对番茄幼苗H+分泌及Pi吸收的影响

磷饥饿条件下番茄幼苗的H⁺分泌速率明显提高。质膜质子泵专一性抑制剂钒酸盐能显著抑制番茄幼苗的H⁺分泌,也能显著抑制其Pi吸收。此结果表明,磷饥饿时番茄幼苗Pi吸收速率的变化与H⁺分泌速率的变化之间可能具有一定的相关性,并进一步暗示质膜H⁺-ATPase可能参与其中。本文结果还表明,Pi/H⁺的准量关系约为1:1。     

NaCl胁迫下大麦根系液泡膜H+-ATPase活性与膜流动性的关系

用50～200 mmol/L NaCl处理2 d后,大麦(Hordeum vulgare L.)品种"滩引2号"(耐盐性强)根的液泡膜H+-ATPase活性增强,600 mmol/L NaCl处理下酶活性下降;"科品7号"(耐盐性弱)在50～100 mmol/L NaCl处理2 d后根的液泡膜H+-ATPase活性增强,200～600 mmol/L NaCl处理下酶活性随盐浓度增加而降低.50～200 mmol/L NaCl处理下"滩引2号"根的液泡膜流动性下降,600 mmol/L NaCl处理下膜流动性明显增大;盐胁迫下液泡膜膜脂脂肪酸不饱和度下降时,膜流动性下降,反之则膜流动性上升.由此推断高盐胁迫下液泡膜膜脂脂肪酸不饱和度上升而引起膜流动性上升可能是引起H+-ATPase活性下降的原因之一.     

盐胁迫下无花果细胞质膜和液泡膜H+-ATPase活性对脯氨酸积累的影响

盐胁迫降低无花果振荡培养细胞培养液pH ,添加质膜H ATPase活性抑制剂Na3VO4 则抑制盐诱导的培养液pH下降 ,表明盐诱导培养液pH下降主要是细胞质膜H ATPase活性增加的结果。NaCl处理提高活体细胞质膜H ATPase活性 ,而降低膜微囊H ATPase活性。培养液中添加Na3VO4 5 0 μmol/L完全抑制盐胁迫下无花果细胞游离脯氨酸积累 ,但添加更高浓度Na3VO4 ,则提高细胞液泡膜H ATPase活性 ,同时Na3VO4 抑制脯氨酸积累的效应下降 ,暗示盐胁迫下无花果细胞质膜和液泡膜H ATPase共同参与细胞质pH调节 ,影响游离脯氨酸积累。     

NaCl胁迫下大麦根液泡膜H+-ATPase活性、离子吸收与钙的关系

NaCl胁迫2 d,耐盐大麦(Hordeum vulgare L.cv) ("滩引2号")根系液泡膜H+-ATPase活性增强,H+-PPase活性下降.以质膜Ca2+通道抑制剂La3+ (1 mmol/L)或Ca2+螯合剂EGTA (5 mmol/L)处理大麦幼苗,抑制了NaCl诱导的液泡膜H+-ATPase活性的增强,但提高了H+-PPase活性;用CaM拮抗剂三氟拉嗪(TFP,20 μmol/L)处理,也抑制了液泡膜H+-ATPase活性的增强.NaCl胁迫下,外加La3+,TFP或La3++TFP处理,使Na+吸收增加,K+和Ca2+吸收降低.结果表明,NaCl胁迫下,液泡膜H+-ATPase活性提高和离子吸收的变化可能与Ca-CaM系统有关.     

Studies on the Proton Pumping Activity of H+-ATPase in Tonoplast Vesicles of Populus euphratica

Tonoplast-enriched vesicles were prepared from suspension-cultured Populus euphratica Oliv. cells by differential centrifugation and discontinuous sucrose density gradient centrifugation. The properties of the proton pumping activity of H+-ATPases in tonoplast vesicles were studied by acridine orange fluorescent quenching measured at 22 ℃. The proton pumping activity of ATPase was ATP-dependent with apparent Michaelis-Menten Constant (Km) for ATP about 0.65 mmol/L. The optimal pH for H+-ATPases activity was 7.5. The proton pumping activity of H+-ATPase could be initiated by some divalent cations, Mg2+ being highly efficient, much more than Fe2+; and Ca2+, Cu2+ and Zn2+ were inefficient under the experimental condition. The proton translocation could be stimulated by halide anions, with potencies decreasing in the order Cl-> Br->I->F-. The proton pumping activity was greatly inhibited by N-ethylmaleimide (NEM), N,N′-dicyclohexylcarbodiimide (DCCD), NO-3 and Bafilomycin A1, but not by orthovanadate and azide. These results demonstrated that the H+-ATPase in the tonoplast of Populus euphratica belonged to vacuolar type ATPase. This work was the first time that tonoplast-enriched vesicles were isolated from Populus euphratica cells.     

NaCl胁迫下大麦根系液泡膜H+-ATP酶活性受ATP和焦磷酸含量的调节

选用两个耐盐性强弱不同的大麦(Hordeumvulgare L.)品种,研究了NaCl胁迫下其幼苗根中ATP和焦磷酸(PPi)含量的变化以及PPi对液泡膜H -ATP酶活性的影响.结果表明:在含NaCl 200mmol/L的1/2 Hoagland溶液中处理2 d,耐盐品种(滩引2号)根中液泡膜H -ATP酶活性增加,然后逐渐下降,而H -PPi酶活性在NaCl处理9 d中'直下降.盐敏感品种(科品7号)在NaCl胁迫下根中H -ATP酶和H -PPi酶活性都下降(图1).与对照相比较,NaCl胁迫下耐盐品种根中ATP含量2 d时增加,4 d后下降;盐敏感品种根中ATP积累受NaCl胁迫的抑制(图2).NaCl胁迫下,两品种的PPi含量皆略有增加(图3).PPi对液泡膜H -ATP酶活性有竞争性抑制作用(图4).结果表明:ATP积累是NaCl胁迫下液泡膜H -ATP酶活性增加的原因之一,NaCl胁迫下大麦品种根中ATP含量下降和PPi对液泡膜H -ATP酶的抑制使该酶活性下降.     

Effects of Salt Stress on the Activity and the Amount of Tonoplast H+-ATPase from Pea Roots

To study the function and adaptive mechanism of tonoplast H+ATPase under salt stress, pea ( Pisum sativum L.) seedlings were treated with different concentrations of salt （100-250 mmol/L NaCl） and with 100 mmol/L NaCl for different days (1-3 d). The ATP hydrolytic activity and the proton transport activity and the changes of the amount of tonoplast H+ ATPase (subunit A) were measured. ATP hydrolytic activity of H+ATPase prepared from plants treated with 250 mmol/L NaCl was reduced by about 25% compared to that of control plants, but that of stressed plants treated with 100 mmol/L and 200 mmol/L NaCl was unchanged. The activity from plants treated with 100 mmol/L NaCl for up to 3 d was lower than that of control plants by 20%. But the proton transport activity was increased under the same salt stresses as above. These results showed that the changes of the hydrolytic activity and the proton transport activity were not in proportion and salt stress may cause the change of the coupling ratio of H+ transport activity to ATP hydrolysis. The protein amount kept unchanged and reduced a little only when pea was treated with 100 mmol/L NaCl for 3 d. These results indicated that salinity stimulated the increase of the pump efficiency of the V-ATPase from pea roots, which was due to the change of the coupling ratio, but not due to the increase of ATP hydrolysis and the amount of V-ATPase.     

水稻幼苗根细胞质膜和液泡膜微囊Ca2+-ATP酶的特性

水稻幼苗根质膜和液泡膜Ca2 -ATP酶对ATP的Km值分别为7.1和4.5 μ mol·L-1;反应的最适pH分别为8.0和7.0.两者活性均受Na3VO4和曙红B(EB)抑制;CPZ抑制质膜Ca2 -ATP酶活性,但促进液泡膜Ca2 -ATP酶活性.30mmol·L-1CaCl2浸种和CaCl2浸种结合低温锻炼预处理,均可提高此酶的活性和冷稳定性.     

High-Pressure Effects on Vacuolar H+-ATPase from Etiolated Mung Bean Seedlings

A high-hydrostatic-pressure technique was employed to study the structure-function relationship of plant vacuolar H⁺-ATPase from etiolated mung bean seedlings (Vigna radiata L.). When isolated vacuolar H⁺-ATPase was subjected to hydrostatic pressure, the activity of ATP hydrolysis was markedly inhibited in a time-, protein concentration- and pressure-dependent manner. The pressure treatment decreased both V _max and K _m of solubilized vacuolar H⁺-ATPase, implying an increase in ATP binding affinity, but a decrease in the ATP hydrolysis activity. Physiological substrate, Mg²⁺-ATP, augmented the loss of enzymatic activity upon pressure treatment. However, ADP, AMP, and Pi exerted substantial protective effects against pressurization. Steady-state ATP hydrolysis was more sensitive to pressurization than single-site ATPase activity. The inactivation of solubilized vacuolar H⁺-ATPase by pressure may result from changes in protein–protein interaction. The conformational change of solubilized vacuolar H⁺-ATPase induced by hydrostatic pressure was further determined by spectroscopic techniques. The inhibition of vacuolar H⁺-ATPase under pressurization involved at least two steps. Taken together, our work indicates that subunit–subunit interaction is crucial for the integrity and the function of plant vacuolar H⁺-ATPase. It is also suggested that the assembly of the vacuolar H⁺-ATPase complex is probably not random, but follows a sequestered pathway.     

NaCl胁迫对宁夏枸杞幼苗根系质膜和液泡膜H+-ATPase活性的影响

以宁夏枸杞为材料,研究NaCl胁迫下枸杞幼苗组织含水量、干物质重量、无机离子分布、质膜透性、丙二醛 (MDA)含量及幼根质膜、液泡膜H -ATPase活性和耐盐性之间的关系。结果表明,在0．3％NaCl胁迫下,干物质重量、质膜透性、MDA含量略有增加,组织含水量略有下降;随着NaCl胁迫强度的增加,Na 、Cl-含量逐渐增加, K 含量则呈现下降的趋势;质膜透性增大与MDA含量升高呈显著正相关;质膜和液泡膜H -ATPase活性逐渐增加,且液泡膜H -ATPase活性显著高于质膜H -ATPase活性,表明枸杞具有较强的抗盐性。     

等渗盐胁迫对番茄抗氧化酶和ATP酶及焦磷酸酶活性的影响

用Ca(NO3)2 80 mmol/L和NaCl 120 mmol/L等渗溶液处理番茄幼苗后,细胞质和叶绿体中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)的活性升高,并且NaCl胁迫的作用明显高于Ca(NO3)2胁迫.Ca(NO3)2处理提高了线粒体中SOD、CAT、APX的活性,而NaCl处理降低了它们的活性.根系质膜H -ATPase、液泡膜H -ATPase、焦磷酸酶(H -PPase)的活性和叶片丙二醛(MDA)及脯氨酸含量在两种盐胁迫后明显增加.NaCl处理对植株生长的抑制程度明显高于Ca(NO3)2处理.