多胺及青霉素对月季切花的保鲜效果

为了筛选出一种高效、经济、无毒、无污染的月季切花保鲜剂,进行了在保鲜剂配方中添加多胺,以及对杀菌剂和无机盐的替代的比较实验研究.结果表明:由于亚精胺能够显著降低乙烯生成量,从而延缓月季切花的衰老进程,延长瓶插寿命.经筛选得到2%蔗糖(S) 200 mg/L柠檬酸(CA) 100 mg/L青霉素 0.15?(NO3)2 0.1 mmol/L亚精胺(Spd)即5号配方保鲜剂可显著延缓月季切花衰老进程,瓶插寿命比对照延长近7 d,花径比对照增加1.46 cm,其各种考察参数都优于其他配方.因此,5号保鲜剂可以作为供试月季品种切花的首选保鲜液.     

月季切花瓶插期间花瓣糖代谢及其相关酶活性的研究

为探究糖代谢及其酶对月季脱离母体后的生命活动的影响,以月季(Rosa hybrida Hort)切花"黑魔术"(cv.Black Magic flower)和"影星"(cv.Movie Star flower)为试验材料,分析瓶插期间花瓣糖代谢及其相关酶活性的变化.试验表明:随着月季切花瓶插时间的延长和花瓣开放,花瓣中葡萄糖(G)和果糖(F)含量显著增加,蔗糖含量随之降低,切花"影星"的己糖(G+F)含量、花径的增长和花朵鲜重都明显高于"黑魔术";花瓣中酸性转化酶(AI)活性与中性转化酶(NI)、蔗糖合成酶(SS)和磷酸蔗糖合成酶(SPS)相比具有较高的水平,AI活性与蔗糖降解指数(SDI)成正相关,AI是降解蔗糖并积累己糖的关键酶,而花瓣中己糖积累在月季切花生长发育过程中起重要作用.     

MET对月季切花品质的影响

用0－1000mg/L的MET溶液喷酒初生花蕾的月季枝条，切花用保鲜液保鲜，在供试的2个品种上均发现：（1）MET可仰制月季切花花头下垂，且随MET浓度增加，抑制作用加强。（2）在100mg/L-500mg/L范围内，MET可延长月季切花的寿命，并增加花冠直径。（3）对于不同的月季品种，MET对提高切花品质的效果有差异。     

6-BA和GA_3配伍对百合切花保鲜效果的影响

研究6-BA和GA3相配合对百合切花的保鲜效应,实验表明:各植物生长调节剂单独处理及其组合处理均能延长百合切花的瓶插寿命,增加花枝鲜重,增大花径;具有维持细胞膜结构稳定性、延缓叶绿素降解等生理效应.通过综合分析与评价各项观测指标,发现2%蔗糖+200 mg/L 8-HQ+300 mg/L柠檬酸+90 mg/L 6-BA+100 mg/L GA3的处理保鲜效果较好.     

环保型保鲜剂对月季切花保鲜效果综合研究

为了寻找高效、无毒、易配制的环保型保鲜剂,利用月季切花瓶插试验研究最优保鲜配方。试验通过评价保鲜剂对月季切花的鲜重、花茎大小、保鲜寿命等因素的影响情况,选择试剂浓度、花枝长度、预处理温度为关键因素,进行三因素三水平正交实验,并以多指标综合评分法进行方差分析,确定月季切花瓶插最优保鲜配方。方差分析表明溶液浓度和预处理温度对月季保鲜影响显著,花枝长度对月季保鲜无显著影响。最终确定月季保鲜最优条件为:切花花枝长度为35 cm,各保鲜剂浓度为100 mg/L,预处理温度为5℃。优选的保鲜剂配方不仅对环境无污染,且能保持月季切花花枝挺立,色彩鲜艳,促使月季花茎大小和鲜重降低速度变慢,可将切花瓶插寿命延长19 d。     

保鲜剂对切花月季衰老进程的影响

本试验研究了不同保鲜剂配方对切花月季品种“黑魔术”(Black Magic)的保鲜效果,主要测定了鲜重、花蕾直径、叶绿素含量、过氧化氢酶活性和花瓣细胞膜透性等生理指标。结果表明,C配方(5%S+200mg/L8-HQC+25mg/LSTS+350mg/LCoCl2·6H2O)对延缓切花月季衰老的效果最佳。     

切花月季营养生理特性研究进展

本文综述了近年切花月季营养生理特性研究进展,对切花月季施肥管理理论的形成和指导切花月季高产优质栽培具有重要作用.     

1-MCP对月季切花保鲜作用的研究

用不同浓度的1-MCP处理月季切花,依据瓶插寿命和外观品质得知以浓度为0.3×10-8的1-MCP处理效果最佳.观测于此浓度1-MCP处理液中瓶插的月季切花的有关外观形态品质和生理生化指标,结果表明与对照相比,1-MCP处理可使月季切花花枝硬挺、蓝变时间延迟,观赏期延长3 d;此外,该处理还具有保持月季花枝鲜重、延迟花瓣质膜相对透性增加,1-MCP处理对花瓣蛋白质和叶片叶绿素含量变化无明显影响.     

水杨酸对香石竹切花保鲜效果的研究

分别以0.5 mmol·L-1、1.0 mmol·L-1、2.0 mmol·L-1、5.0 mmol·L-1和10.0 mmol·L-1 浓度的水杨酸(SA)处理高温季节的香石竹(Dianthns caryophyllus)切花,通过与对照相比较,探讨SA对香石竹切花的保鲜效果.结果表明,SA浓度在0.5～10.0 mmol·L-1下,均有不同程度地增加切花鲜重、增大花径的作用;0.5～2.0 mmol·L-1SA能延长切花瓶插寿命,提高切花外观品质,维持较高水平超氧化物歧化酶(SOD)活性和蛋白质含量,延缓膜透性的增加,其中以1.0 mmol·L-1和2.0 mmol·L-1浓度SA保鲜效果最好.     

力竭运动对大鼠骨骼肌肌浆网钙转运的影响

采用递增负荷力竭运动方式观察急性运动对肌浆网(SR)钙转运能力的影响,发现运动后股四头肌SR Ca2+-ATPase活性和Ca2+摄取速率均明显下降,表现为SR Ca2+-ATPase活性和Ca2+摄取速率分别下降51.12%(P<0.01)和17.72%(P<0.01);而脂质过氧化物浓度则显著升高,增加48.85%(P<0.01).提示急性运动后SR Ca2+-ATP ase 活性和Ca2+摄取速率下降可能是脂质过氧化增高的结果,而Ca2+摄取功能下降可能与运动性疲劳密切相关.     

Ca~(2+)和Co~(2+)对百合切花保鲜效果的影响

探讨了不同浓度处理的无机盐CaCl2和CoNO32溶液对瓶插百合切花保鲜效果的影响.结果表明:CaCl2和CoNO32配合使用可以使百合切花花枝硬挺,花径增大,改善切花的观赏品质,延长瓶插寿命;同时,还具有保持百合切花花枝鲜重、维护花瓣细胞膜透性的稳定、维持瓶插溶液pH值保持在适合的浓度范围之间、缓解叶绿素的降解等作用.通过对各处理的各项指标的综合观测与分析可知,以0.1%CaCl2和0.05‰CoNO32溶液的配合使用对百合切花的保鲜效果最好.     

化学保鲜剂对马蹄莲切花抗氧化酶活性的影响

以马蹄莲切花为试材,研究含水杨酸（SA）的保鲜剂与含AgNO3和6-BA的2种传统保鲜剂对切花抗氧化酶活性的影响．结果表明：在整个瓶插过程中,所有处理的SOD活性变化的趋势均呈M型,经保鲜剂处理的各组均能在后期保持较高的SOD活性;经保鲜剂处理的各组CAT和POD的活性也有不同程度的提高,且保持在较高水平的时间也比较长．这说明3种化学保鲜剂能在一定程度上减轻活性氧对马蹄莲切花的破坏,但以0．5％蔗糖＋0．1Ca（NO3）,＋50mg／LSA最优．     

无机盐溶液对香石竹切花的保鲜效应

银盐通常作为切花保鲜剂中的一种重要无机盐,但是它们具有很高的生理毒性且污染环境,因此,本文研究了K+、Co2+和Al3+等几种无机盐离子及其相互配合对香石竹切花的保鲜效应,以期取代Ag+.结果表明:各无机盐溶液处理均能不同程度地提高切花观赏品质,延缓切花衰老进程.通过综合评价,以50mgL1Al2SO43+100mgL1KCl处理效果最佳,可使香石竹切花保鲜达到24d.     

Ca2+延长月季切花寿命研究

分别于2001年12月18～26日，2002年1月7～14日和13～21日用无水氯化钙配制成Ca^2 浓度为0mg／ml，2．5mg／ml，5．0mg／ml，7．5mg／ml，10．0mg／ml，15．0mg／ml，20.0mg／ml的Ca^2 溶液作保鲜剂，研究Ca^2 对月季切花瓶插寿命的影响。试验的不同浓度为不同处理组，每个处理组20枝花，从切花插入保鲜液开始，每隔6h或12h观察月季花瓣枯萎程度，并测量月季的花径、花重、吸水率。结果表明，Ca^2 溶液对月季切花有一定的保鲜作用。Ca^2 有利于保持花枝的水分平衡，增加花枝的鲜重，从而增加花瓣的紧张度，保持花的姿态，延长花的寿命。以10．Omg／ml Ca^2 浓度的效果最好。     

Turning of nerve growth cones induced by localized increases in intracellular calcium ions

Guidance of developing axons involves turning of the motile tip, the growth cone, in response to a variety of extracellular cues. Little is known about the intracellular mechanism by which the directional signal is transduced. Ca2+ is a key second messenger in growth cone extension and has been implicated in growth-cone turning. Here I report that a direct, spatially restricted elevation of intracellular Ca2+ concentration ([Ca2+]i) on one side of the growth cone by focal laser-induced photolysis (FLIP) of caged Ca2+ consistently induced turning of the growth cone to the side with elevated [Ca2+]i (attraction). Furthermore, when the resting [Ca2+]i at the growth cone was decreased by the removal of extracellular Ca2+, the same focal elevation of [Ca2+]i by FLIP induced repulsion. These results provide direct evidence that a localized Ca2+ signal in the growth cone can provide the intracellular directional cue for extension and is sufficient to initiate both attraction and repulsion. By integrating local and global Ca2+ signals, a growth cone could thus generate different turning responses under different environmental conditions during guidance.     

IBA对月季切花‘黑魔术’保鲜效应的影响

为探究外源吲哚丁酸(IBA)对月季鲜切花的保鲜效应,采用蔗糖+水杨酸(SA)为基础保鲜液,分别添加不同浓度梯度的IBA,对月季‘黑魔术’鲜切花进行瓶插保鲜处理,观察分析鲜切花的各项生理指标.结果表明:保鲜处理12 d后,不同浓度IBA对鲜切花的生长和品质产生了不同的影响.IBA质量浓度为250 mg·L~(-1)的保鲜液处理组,鲜切花完全萎蔫,丧失观赏价值.IBA质量浓度为500 mg·L~(-1)的保鲜液处理组中,鲜切花能维持较好的花瓣形态,花朵于第6 d进入盛花期,绽放冠幅达8 cm,且最终花瓣萎蔫率仅为24.3%.同时,该处理组较其他组生理状态更佳,水分平衡值和鲜重维持在较好的水平,超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性提高,花瓣中蔗糖含量显著高于其他处理组.进一步分析影响花瓣脱落相关基因的表达,其中RcSUC2,RcARF7因外源施加了蔗糖和生长素,导致体内基因表达相对于对照组显著降低,而乙烯与生长素的拮抗作用也使得RcETR1的表达显著降低.基于上述研究结果,筛选获得对月季‘黑魔术’鲜切花保鲜效果最佳的保鲜液配方.研究结果为月季切花保鲜应用提供了理论依据和技术参考.     

影响宁夏枸杞愈伤组织体细胞胚发生的因素

对宁夏枸杞愈伤组织体细胞胚发生的影响因素进行分析,结果表明,宁夏枸杞根外植体的年龄及其生理状态能影响胚性愈伤组织的形成和体细胞胚发生;4℃低温处理两周能明显促进愈伤组织形成体细胞胚,同时也能增加愈伤组织内源多胺的含量;添加Ag+有利于愈伤组织的体细胞胚发生,适当增加Ca2+浓度也有利于愈伤组织的生长及其体细胞胚发生;Eu3+的添加能明显促进愈伤组织生长,而低浓度的Ce2+、Eu3+作用有利于愈伤组织体细胞胚发生.     

Molecular identification of the CRAC channel by altered ion selectivity in a mutant of Orai

Recent RNA interference screens have identified several proteins that are essential for store-operated Ca2+ influx and Ca2+ release-activated Ca2+ (CRAC) channel activity in Drosophila and in mammals, including the transmembrane proteins Stim (stromal interaction molecule) and Orai. Stim probably functions as a sensor of luminal Ca2+ content and triggers activation of CRAC channels in the surface membrane after Ca2+ store depletion. Among three human homologues of Orai (also known as olf186-F), ORAI1 on chromosome 12 was found to be mutated in patients with severe combined immunodeficiency disease, and expression of wild-type Orai1 restored Ca2+ influx and CRAC channel activity in patient T cells. The overexpression of Stim and Orai together markedly increases CRAC current. However, it is not yet clear whether Stim or Orai actually forms the CRAC channel, or whether their expression simply limits CRAC channel activity mediated by a different channel-forming subunit. Here we show that interaction between wild-type Stim and Orai, assessed by co-immunoprecipitation, is greatly enhanced after treatment with thapsigargin to induce Ca2+ store depletion. By site-directed mutagenesis, we show that a point mutation from glutamate to aspartate at position 180 in the conserved S1-S2 loop of Orai transforms the ion selectivity properties of CRAC current from being Ca2+-selective with inward rectification to being selective for monovalent cations and outwardly rectifying. A charge-neutralizing mutation at the same position (glutamate to alanine) acts as a dominant-negative non-conducting subunit. Other charge-neutralizing mutants in the same loop express large inwardly rectifying CRAC current, and two of these exhibit reduced sensitivity to the channel blocker Gd3+. These results indicate that Orai itself forms the Ca2+-selectivity filter of the CRAC channel.     

Effects of protein kinase C activators on cardiac Ca2+ channels

Phorbol esters have marked effects on voltage-dependent Ca2+ channels. Inhibitory and stimulatory effects on cardiac Ca2+ channels have been attributed in both cases to activation of protein kinase C. We show that the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate stimulates dihydropyridine-sensitive 45Ca2+ influx in primary cultures of neonatal rat ventricular myocytes within 5 s, but that after a 20-min pre-incubation period the phorbol ester markedly inhibits 45Ca2+ influx. The sequence of stimulation followed by inhibition is confirmed in cell-attached patch clamp recordings of single Ca2+ channel currents. The stimulatory effect is faster at 0 mV than at -40 mV, leading to the novel conclusion that the rate of protein kinase C activation is modulated by the state of the Ca2+ channel.     

Study on the effect of doxorubicin on expressions of genes encoding myocardial sarcoplasmic reticulum Ca^2＋ transport proteins and the effect of taurine on myocardial protection in rabbits

To investigate the effect of doxorubicin(DOX) on gene expression of the myocardial sarcoplasmic reticulum (SR)Ca^2 transport proteins and the mechanism of taurine(Tau) protecting cardiac muscle cells, 9 rabbits were injected with DOX , 8 rabbits with DOX and Tau, and 9 rabbits with normal saline. Cardiac function , concentration of calcium in cardiomyocytes ( Myo [ Ca^2 ]i ), activity of SR Ca^2 -ATPase (SERCA2a) , level of SERCA2a mRNA and Ca^2 released channels(RYR2) mRNA were detected. The left ventricle tissues were observed by electron microscopy. The results showed that cardiac index, left ventricular systolic pressure, activity of SR Ca^2 -ATPase and level of SERCA2a mRNA decreased , while Myo[ Ca^2 ]i increased in DOX-treated rabbits. DOX could not affect the level of RYR2 mRNA. Tau intervention could alleviate the increase of left ventricular diastolic pressure, Myo[ Ca^2 ] i and the decrease of SERCA2a mRNA induced by doxorubicin. Tile results suggested that downregulation of SERCA2a gene expression was an important mechanism of DOX-induced cardiomyopathy and that Tau could partially improve the heart function by reducing calcium overload and alleviating downregulation of SERCA2a mRNA.