Ca^2＋ is involved in muscarine-acetylcholine-receptor-mediated acetylcholine signal transduction in guard cells of Vicia faba L.

Acetyicholine (ACh) is an important neuro-chemical transmitter in animals; it also exists in plants and plays a significant role in various kinds of physiological functions in plants. ACh has been known to induce the stomatal opening. By monitoring the changes of cytusolic Ca^2 with fluorescent probe Fiuo-3 AM under the confocal microscopy, we found that exogenous ACh increased cytosolic Ca^2 concentration of guard cells of Vicia faba L. Muscarlne, an agonist of muscarine acetyicholine receptor (mAChR), could do so as well. In contrast, atropine, the antagonist of mAChR abolished the ability of ACh to increase Ca^2 in guard cells. This mechanism is similar to mAChR in animals. When EGTA was used to chelate Ca^2 or ruthenium red to block Ca^2 released from vacuole respectively, the results showed that the increased cytosolic Ca^2 mainly come from intracellular Ca^2 store. The evidence supports that Ca^2 is involved in guard-cell response to ACh and that Ca^2 sigual is coupled to mAChRs in ACh signal transduction in guard cells.     

Involvement of nitric oxide in the signal transduction of salicylic acid regulating stomatal movement

The effects and the relationship between sali-cylic acid(SA)and nitric oxide(NO) on Vicia faba L.stomatal movement were studied.The results here showed that exogenous SA and NO induced stomatal closure,100μmol/L SA induced a rapid and striking NO increase in the cytosol of guard cells.This phenomenon was largely prevented by 2000μmol/L 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide(PTIO),a specific NO scavenger,and 25μmol/L N^G-nitro-L-Arg-methyl eater (L-NAME),an inhibitor of NO synthase(NOS) in mammalian cells that also inhibits plant NOS.In addition,SA-induced stomatal closure was largely prevented by PTIO and L-NAME.These results provide evidence that guard cells generate NO in response to SA via NOS-like activity,and that such NO production is required for full stomatal closure in response to SA.H-(1,2,4)-oxadiazole-[4,3-α]quinoxalin-l-one(ODQ),an inhibitor of guanylate cyclase,and nicotinamide,an antagonist of cADPR production,inhibited the effects of SA-and NO-induced stomatal closure.It suggests that both cGMP and cADPR might mediate the signal transduction of SA and NO-induced stomatal closure.     

Role of acetylcholine on plant root-shoot signal transduction

The role of accetylcholine (ACh) on plant root-shoot communication was investigated using the root-split system of Vicia faba L.In the experiments,slight osmotic stress caused the decrease of ACh content in root tips and the xylem sap transported up per time unit from root tip to the shool when the water potential of the shoot was kept unchanged .It also caused the decrease of ACh content in the abaxial epidermis,The decrease was highly correlative to the changes of transpiration rate,suggesting that the decrase of ACh content probably functions as a signal to regulate stomatal behavior,The effect of osmotic stress might be mainly through the inhibition of the ACh synthesis in root tip ;thus further influences the ACh content in root tip ,xylem sap and abaxial epidermis and resulting in the changes of stomata behavior,These results provide new evdence that plants transduce positive and negative signals among roots and shoot to coordinate stomatal behavior and adapt to variable environments.     

Nitric oxide involved in signal transduction of Jasmonic acid-induced stomatal closure of Vicia faba L.

Nitric oxide (NO) and Jasmonic acid (JA) are two key signaling molecules involved in many and diverse biological pathways in plants. Growing evidence suggested that NO signaling interacts with JA signaling. In this work, Our experiment showed that NO exists in guard cell of Vicia faba L., and NO is involved in signal transduction of JAinduced stomata closuring: ( i ) JA enhances NO synthesis in guard cell; ( ii ) both JA and NO induced stomatal closure, and had dose response to their effects; ( iU ) there are synergetic correlation between JA and lower NO concentration in regulation of stomatal movement; (iV) JA-induced stomatal closure was largely prevented by 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide (PTIO), a specific NO scavenger. An inhibitor of NO synthase (NOS) in mammalian cells, N^G-nitro-L-Arg-methyl eater (L-NAME) also inhibits plant NOS, repressing JA-induced NO generation and JA-induced stomatal closure. We presumed that NO mainly comes from NOS after JA treatment.     

蚯蚓钙调素二级结构的研究及Ca^2＋,Tb^3＋的影响

运用ＦＴ－ＩＲ方法的分辨率增强及曲线拟合技术对水化膜中蚯蚓钙调素ＣａＭ的二级结构以及加入不同比例Ｃａ＾２＋、Ｔｂ＾３＋后ＣａＭ二级结构的变化进行了研究。结果表明，水化膜中ＣａＭ及含不同比例Ｃａ＾２＋或Ｔｂ＾３＋的蛋白复合物的α－ｈｅｌｉｘ的含量较晶体和溶液中为低，而β－ｓｈｅｅｔ和ｔｕｒｎ结构的含量相对较高。研究发现不同比例金属离子的加入，引起了ＣａＭ二级结构不同程度的变化，但各类结构在总量上观察     

^40Ar／^39Ar geochronological constraints on syn-orogenic strike-slip movement of Tan-Lu fault zone

Two phases of sinistral strike-slip ductile shear belts occur on the eastern margin of the Dabie orogenic belt. A muscovite ~(40)Ar/~(39)Ar plateau age of 128 Ma was obtained from mylonite in the later ductile shear zone. Three muscovite samples separated from mylonites of 3 localities in the earlier ductile shear belts yield ~(40)Ar/~(39)Ar plateau ages of 192.5±0.7 Ma, 189.7±0.6 Ma and 188.7±0.7 Ma, respectively. They are interpreted as cooling ages of the earlier sinistral strike-slip deformation. It is suggested that left-lateral displacement of the Tan-Lu fault zone started in a late stage of the collision orogeny in the Dabie-Sulu orogenic belt between the North and South China plates. Therefore, the earlier Tan-Lu fault zone was syn-orogenic strike-slip tectonics. The fault zone was used again for sinistral displacement during tectonic activities of peri-Pacific regime in Early Cretaceous. It is proposed that the fault zone occurred as a transform fault during the orogenic process.     

生长素和细胞分裂素在光、暗调控气孔运动中的作用及其机制

借助表皮条实验和激光扫描共聚焦显微镜技术,研究了天然和合成生长素IAA、NAA、2,4-D、细胞分裂素ZT、KT、6-BA在光、暗调控气孔运动中的作用及其机制.结果表明,暗中所试生长素、细胞分裂素、NO清除剂cPTIO、Hb、NO合酶抑制剂L-NAME、H2O2清除剂AsA、CAT、H2O2产生酶NADPH氧化酶抑制剂DPI对气孔开放的效应显著大于光下,暗示内源生长素、细胞分裂素、NO、H2O2均参与光/暗调控气孔运动,光下内源生长素、细胞分裂素浓度大于暗中,但暗中内源NO、H2O2水平高于光下.另外,所试生长素、细胞分裂素和NO、H2O2清除剂及合成抑制剂对光、暗条件下气孔运动效应的一致性还表明,生长素、细胞分裂素可能通过降低保卫细胞内源NO、H2O2促进气孔开放,内源NO、H2O2检测的结果正好证明了这一推论.     

植物Ca2+-CaM信号系统及其调控研究进展

Ca2 信号通路是植物中信号转导已确认的主要途径.CaM(钙调蛋白)是目前已知胞内Ca2 信号受体中最重要的一种,它参与了多种生理活动的调节.文章对钙在植物细胞中的存在形式、钙作为植物信号转导中第二信使的作用、植物钙调蛋白的结构和生理功能等问题进行了综述和探讨.     

活性氧与NO在SO2诱导蚕豆气孔运动中的作用

以蚕豆叶表皮为材料,研究SO2胁迫时叶面气孔运动及其调节途径.研究发现,用浓度1～200μmol/L的SO2衍生物(亚硫酸钠与亚硫酸氢钠混合液)处理蚕豆叶下表皮后,气孔开度明显减小,气孔保卫细胞内活性氧(ROS)、一氧化氮(NO)和钙离子(Ca2+)水平显著升高.采用抗氧化剂抗坏血酸和过氧化氢酶,钙离子干扰剂EGTA和LaCl3,以及NO合成抑制剂NaN3与NO清除剂c-PTIO,分别与SO2衍生物同时作用时,SO2诱发的气孔关闭效应得到有效缓解,保卫细胞内ROS、NO和Ca2+水平随之改变.抗氧化剂和NO干扰剂能阻止SO2诱导的胞内ROS、NO和Ca2+水平升高;EGTA和LaCl3能降低SO2诱导的胞内NO和Ca2+升高,但不影响ROS水平.研究结果表明,较高浓度SO2能诱导气孔关闭,SO2胁迫诱导ROS和NO合成增加,ROS和NO通过钙信号系统调节气孔开度.     

Cardiac protective role of a novel erythrocyte-derived depressing factor on rats and its Ca^2＋ mechanism

The cardiac protective role of a novel erythro-cyte-derived depressing factor (EDDF) on spontaneous hy-pertensive rats (SHR), calcium overload (CaO) rats and Wistar rats and its mechanism was evaluated. Mean artery pressure (MAP), heart rate (HR) and LVdp/dtmax were measured by physiological recorder. The effect of EDDF on the Ca2+-ATPase activity in myocardial sarcoplasmic reticu-lum (SR) of CaO rats was determined by inorganic phos-phate assay. Calcium transport in myocytes was measured by 45Ca2+ radioactive isotope measurement. The phosphoryla-tion levels of extracellular signal-regulated protein kinases (ERK1/2) in myocardial tissue of SHR and CaO rats were measured by Western blot method. And the ultrastructures of cardiac muscle cells were observed with the transmission electron microscope. The results indicated that EDDF could significantly decrease MAP, HR and LVdp/dtmax in a dose dependent manner (P < 0.05). It seems that the mechanism might relate with activating the Ca2+-APTase, enhancing the uptake and release of Ca2+ from SR (P < 0.05), decreasing the phosphorylation levels of ERK1/2 of myocytes (P < 0.01) and lightening the ultrastructural lesion of cardiac muscle cells. In CaO rats, the Ca2+-ATPase activity decreased clearly com-pared to control (64.99 7.16 vs 94.48 7.68 nmol·min-1 ·mg-1 protein, P < 0.01), while EDDF (100 mg/mL) could significantly increase the activity (87.93 ?9.54 vs 64.99 ?7.16, P < 0.05, n = 7). Both uptake and release rate of Ca2+ (祄ol 45Ca2+/g protein/min) from myocardial SR of CaO rats re-markably decreased compared to control (32.40 ?2.70 and 15.46 ?1.49 vs 61.09 ?10.89 and 25.47 ?4.29, P < 0.05); EDDF (100 mg/mL) could significantly stimulate their activi-ties (50.48 6.76 and 21.76 2.75 vs 32.40 2.70 and 15.46 1.49, P < 0.05). EDDF could evidently down-regulate the phosphorylation of ERK1/2 in myocardial tissue from SHR and CaO rats (P < 0.01), lighten the ultrastructural lesion of cardiac muscle cells of SHR as well. It is concluded that EDDF seems to play protective roles on both structure and function of heart, which closely related with amelioration of Ca2+ transport and inhibition of Ca2+-MAP kinase pathway.     

Involvement of carbon monoxide produced by heme oxygenase in ABA-induced stomatal closure in Vicia faba and its proposed signal transduction pathway

Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO production and heme oxygenase (HO) activity, an important CO synthetic enzyme, are first reported to increase in response to ABA treatment, which could result in stomatal closure. Inter- estingly, ABA-induced stomatal closure in V. faba guard cells is partially blocked when the synthetic CO inhibitor ZnPP, or the CO/NO scavenger Hb is added. Furthermore, we show that, exogenously applied CO donor, hematin, and CO aqueous solution not only result in the enhancement of CO release, but also time-dependently induce stomatal closure, and the latter is mimicked by the application of an NO donor SNP. The above-mentioned stomatal closure effects are differentially reversed by the addition of tungstate, a potent inhibitor of NO synthetic enzyme nitrate reductase (NR), the specific NO scavenger cPTIO, ZnPP, or Hb. During treatment for 4 h, SNP, 0.01% CO aqueous solution or hematin significantly triggers NO synthesis, whereas cPTIO, or tungstate approximately fully inhibits NO fluorescence. Ad- ditionally, application of the GC inhibitor ODQ blocks CO-induced stomatal closure. This inhibition could be reversed when 8-Br-cGMP is added. Thus, the above results suggest that CO produced by HO is involved in ABA-induced stomatal closure, and NO and cGMP may function as downstream interme- diates in the CO signaling responsible for stomatal closure.     

Apoptosis of RKO induced by catechins and GA through Ca<Superscript>2+</Superscript> and LIP

The anti-tumor effects of catechins and gallic acid （GA） in-vitro was investigated in this paper. Fluo-3AM, Calcium-AM （Ca-AM）, 2＇, 7＇ -dichlorofluorescein-diacetate（DCFH-DA）, 4＇ ,6-dia- midino-2- phenylindole （DAPI） and Ca-AM plus colbat were used to characterize intracellular calcium, labile iron pool （LIP）, reac- tive oxygen species （ROS）, nuclei morphology and mitochondrial permeability transition pore （mPTP） opening, respectively. High performance liquid chromatography （HPLC） was used to quanti- tare catechins and GA in the cultural medium. The results indi- cated that each of them showed dose response inhibition of cell growth, provoking nuclei condensation, intracellular calcium ele- vation, mPTP opening, LIP reduction, and cytochrome c （Cyt-C） to release into cytosol. The caspase inhibitors, 2-aminoethox- ydiphenol borate （APB） or Fe3＋ could inhibit lethal effects of GA and （-）-epigallocatechin （EGC）, but failed to affect （-）-epigalloca- techin gallate （EGCG） and （-）-epicatechin gallate （ECG）. Level of ROS presented negative growth while their concentration de- creased in the medium. In conclusion, our findings suggest that viability of RKO decreased because of their good correlation with elevation of calcium and loss of L1P and ROS in cytosol.     

Luminescent research of Sr5（PO4）3Cl：Eu^2＋ blue phosphor used for electron beam excitation

Eu^2 -aetivated strontium choloro-phosphate has been used for lamp phosphor traditionally with high efficiency. In this paper, the cathodoluminescent properties of Sr5(PO4)3Cl：Eu^2 have been investigated for application in field emission display. The influence of Ba^2 , Ca^2 impurities on the cathodoluminescent spectrum of Sr5(PO4)3Cl:Eu^2 has also been measured. When operate voltage varied from mid- to low-voltage, the relative brightness and saturation behavior of phosphor was observed at different current density.     

ISEA reversed event in the Cretaceous Normal Super-chron （CNS）： ^40Ar／^39Ar dating and paleomagnetic results

ThegeomagneticfieldwasfoundtobeofnormalpolarityforalongtimeduringtheCretaceousbyHelsleyandSteiner[1]andthiswaslaternamedasCretaceousNormalSuperchron(CNS)[2].TheCNSlastedalmost37Ma(120—83Ma).Severalabnormalgeologicalevents,suchasanoceanicanoxicevent,alargenumberofvol-canismandglobalclimaticwarmingduringtheCNShavebeenreported[3—11].Thishasledtomanyquestionsbeingraised.IsittruethattheEarthsmagneticfielddidnotreverseatallintheCNS?Ifitdidreverse,howmanytimesandwhendidthishappen?Istherea…     

Rearrangements of microtubule cytoskeleton in stomatal closure of <Emphasis Type="Italic">Arabidopsis</Emphasis> induced by nitric oxide

NO （nitric oxide）, known as a key signal molecule in plant, plays important roles in regulation of stomatal movement. In this study, microtubule dynamics and its possible mechanism in the NO signal pathway were investigated. The results were as follows： （i） In vivo stomatsl aperture assays revealed that both vinblastine （microtubule-disrupUng drug） and SNP （exogenous NO donor） prevented stomatsl opening in the light, and vinblastine even could enhance the inhibitory effect of SNP, whereas tsxol （a microtubule-stsbilizing agent） was able to reduce this effect; （ii） microtubules in the opening Arabi-dopsis guard cells expressing GFP：a-tubulin-6 （AtGFP：a-tubulin-6） were organized in parallel, straight and dense bundles, radiating from the ventral side to the dorsal side, and most of them were localized perpendicularly to the ventral wall; （iii） under the same environmental conditions, treated with SNP for 30 min, the radial arrays of microtubules in guard cells began to break down, twisted partially and be- came oblique or exhibited a random pattern; （iv） furthermore, the involvement of cytosolic Ca^2＋ in this event was tested. Stomatal aperture assays revealed that BAPTA-AM （a chelator of Ca^2＋） greatly suppressed the effect of NO on stomatal closure; however, it did not show the same function on stomatal closure induced by vinblastine. When BAPTA-AM was added to the SNP-pretreated solution, the SNP-induced disordered microtubulue cytoskeleton in guard cells underwent rearrangement in a time-dependent manner. After 30 min of treatment with BAPTA-AM, the cortical microtubules resumed the original radial distribution, almost the same as the control. All this indicates that NO may promote rearrangement of microtubule cytoskeleton via elevation of [Ca^2＋]cyt （free Ca^2＋ concentration in the cytoplasm）, finally leading to stomatsl closure.     

头孢噻肟对人外周血淋巴细胞钙信号转导作用的研究

以人外周血淋巴细胞为模型,利用稳态荧光法研究该模型在外源药物头孢噻肟刺激下,细胞钙稳态的变化,同时考察了钙-ATP酶活性与钙稳态之间的关系.研究发现,在低浓度组的头孢噻肟钠(0.005 g/L)刺激下,淋巴细胞内钙离子浓度略有增加,而胞外的钙离子浓度几乎没有发生变化.当药物浓度继续增加,胞内钙离子浓度逐渐减少,药物浓度与胞内钙离子浓度呈现出一定的剂量效应关系.不同药物处理组的钙-ATP酶活性与对照组相比均降低,呈现出一定的剂量-效应关系.     

Effects of Yb^3＋ codoping on visible and near infrared emissions of Er^3＋-Yb^3＋ codoped Al2O3 powders by the sol-gel method

The 0.1 mol% Er^3＋ and 0-2 mol% Yb^3＋ codoped Al2O3 powders were prepared by the sol-gel method, and the phase structure, including only two crystalline types of doped Al2O3 phase, γ-（Al,Er, Yb）2O3 and θ-（Al,Er, Yb）2O3, was detected at the sintering temperature of 1000℃. The visible and near infrared emissions properties depended strongly on the Yb^3＋ codoping, and the corresponding maximal peak intensities centered at about 523, 545, 660 and 1533 nm were obtained respectively for the 0.1 mol% Er^3＋ and 0.5 mol% Yb^3＋ codoped Al2O3 powders, which were composed of θ-（Al,Er,Yb）2O3 and a small amount of γ-（Al,Er, Yb）2O3 phases. The two-photon absorption process was responsible for the visible up-conversion emissions, and the one-photon absorption process was involved in the near infrared emissions of the Er^3＋-yb^3＋ codoped Al2O3 powders.     

Kinetic parameters of oscillating reaction of amino acid- BrO3^——Mn^2＋-H2SO4-acetone system

In the previous papers[1—3], the oscillating reactionusing amino acids as organic substrates was studied. Inorder to obtain information about the kinetic parameters ofoscillating reaction of amino acids in amino acid- BrO3 - ?Mn2 -H2SO4-acetone sy…     

Characteristics of Pb<Superscript>2+</Superscript> biosorption with aerobic granular biomass

Experimental studies were conducted on the feasibility of aerobic granular biomass as a novel type of biosorbent for Pb^2＋ removal. The results show that the initial pH, Pb^2＋ concentration （Co） and biomass concentration （X0） affected the biosorption process significantly. Both the Freundlich and Langmuir isotherm models describe the biosorption process accurately, with correlation coefficients of 0.932 and 0.959 respectively. The Pb^2＋ biosorpUon kinetics is interpreted as having two stages, with the second stage described reasonably well by a Lagergren pseudo-second order model. Moreover, the surface change of granular biomass after the Pb^2＋ biosorption process appears to be caused by ion exchange and metal chelation according to the analysis results of Environmental Scanning Electron Microscopy （ESEM） and Energy Dispersive X-ray Spectroscopy （EDX）.     

Resistless photochemical etching of a silicon wafer by UV laser with an H<Superscript>2</Superscript>O<Superscript>2</Superscript> and HF aqueous solution

A new resistless etching method has been developed for Silicon wafers. This new method uses an aqueous solution consisting of hydrogen peroxide (H₂O₂) and hydrogen fluoride (HF) as the activating etchants. A 193 nm ArF excimer laser and a 266 nm fourth harmonic generation Nd: YAG laser were used as the photon sources. Results showed that pattern etching has been achieved without any photoresist film. In the case of the 193 nm laser, the optimal etching appeared at a 1.3 H₂O₂÷HF ratio, where an etch depth of 210 nm was achieved with a fluence of 29 mJ/cm² and shot number of 10000. At the same conditions, the etch depth with H₂O₂ and HF solution was three times of that by using H₂O and HF mixture. In the case of the 266 nm Nd: YAG laser, the optimal etching appeared at twice ratio of H₂O₂/HF, where the etch depth of 420 nm was achieved with a fluence of 12 mJ/cm² and shot number of 30000. Results showed that the etch effect of the 266 nm Nd: YAG laser was more desirable than that of the 193 nm ArF excimer laser.