共查询到19条相似文献，搜索用时 546 毫秒
1.
利用焦锑酸钙沉淀和硝酸铅沉淀的电镜细胞化学方法,以室温生长的北海道黄杨植株为对照,研究了人工4 ℃低温胁迫过程中北海道黄杨（Euonymus japonicus‘Cuzhi’）叶肉细胞Ca2+和Ca2+-ATPase的动态变化。在4 ℃低温胁迫的初期（3 ~ 12 h）,北海道黄杨叶肉细胞间隙和液泡内的Ca2+沉淀颗粒减少,而细胞质和细胞核内的Ca2+水平升高,但Ca2+-ATPase在细胞的分布几乎没有变化,主要分布在质膜和液泡膜上,有较高的活性;低温胁迫24 h,细胞质和细胞核内增加的Ca2+开始回到细胞间隙和液泡中,Ca2+-ATPase在质膜和液泡膜上活性增强;在低温胁迫48 ~ 96 h,细胞内的Ca2+又回到低温胁迫前的低水平,但Ca2+-ATPase在质膜和液泡膜上仍有很高的活性。叶肉细胞内Ca2+稳态平衡和Ca2+-ATPase的活性变化与植物的抗寒性存在一定的相关性。 相似文献
2.
梨果实发育中Ca2+在果肉细胞的定位及变化研究* 总被引：17，自引：3，他引：14
用焦锑酸钾沉淀的细胞化学方法, 研究了 幸水 梨果实发育中果肉细胞的焦锑酸Ca2+ 定位变化及其与细胞超微结构的关系。结果表明: ( 1) 在未受精之前, 果肉细胞内未检测到Ca2+ 沉淀颗粒, 细胞核内的染色质少且染色淡, 细胞质的细胞器数量也少; ( 2) 受精后果肉细胞呈现大量的Ca2+沉淀颗粒, 主要分布在细胞核、细胞质、质体以及叶绿体外膜上, 含Ca2+沉淀颗粒的质体非常膨大, 导管和初期发育的石细胞内也密集分布Ca2+ 沉淀颗粒; ( 3) 受精1 周后果肉细胞的Ca2+移向细胞之间的连接处; ( 4) 生理落果的细胞和导管中Ca2+没有或极少, 但有的细胞内沿液泡膜有Ca2+分布; ( 5) 受精3~ 4 周后, 果肉细胞中很难检测到Ca2+沉淀颗粒, 此状态一直持续到果实采收, 但果实腐烂前Ca2+沉淀颗粒沿果肉细胞
壁两侧出现。就Ca2+ 在果实发育中的作用及与细胞超微结构的关系等进行了讨论。 相似文献
3.
以藤本月季“大游行”为试材,采用土壤喷施0、200 mmol·L-1盐溶液的处理方法,探究不同浓度外源Ca2+(0、5、10、20 mmol·L-1)对藤本月季光合以及氮代谢相关酶活性的影响,以期为外源Ca2+缓解盐胁迫对藤本月季的伤害提供参考依据。结果表明：一定浓度外源Ca2+能够增加藤本月季株高生长量、叶面积和地上生物量,促进光合作用,提高叶片中光合色素含量以及氮代谢相关酶活性来增强植物抗性。在200 mmol·L-1盐处理下,与0 mmol·L-1Ca2+处理浓度相比,添加10 mmol·L-1Ca2+浓度处理下藤本月季的叶绿素a、叶绿素b、总叶绿素(a+b)以及叶黄素含量分别增加了143.9%、152.5%、151.9%和90.6%;光合参数中水分利用效率(WUE)、净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)和气孔导度(G... 相似文献
4.
为揭示蓝光处理促进黄肉桃果实类胡萝卜素积累的机制,以黄肉桃‘金丽’果实为研究对象,从桃基因组中筛选出PpSGR1和PpSGRL基因进行生物信息学分析,并通过q-PCR分析PpSGR1和PpSGRL在不同组织和不同发育阶段果实及其在40 μmol · m-2 · s-1蓝光处理果实中的表达。结果表明,PpSGR1具有多半胱氨酸保守域,属于SGR亚族;PpSGRL基因C端突变失去多半胱氨酸保守域,属于SGR-Like亚族;PpSGR1和PpSGRL都含有叶绿体信号肽,与梅亲缘关系最近。PpSGRs在‘金丽’桃不同组织和不同成熟阶段果实中均有表达,其中PpSGR1与果实采后类胡萝卜素的合成密切相关。蓝光处理可快速抑制桃果实PpPIF3进而抑制PpSGR1的转录,促进贮藏前期果实中PpPSY的表达,提高类胡萝卜素的合成和积累。同时,蓝光处理可能通过促进桃果实内源乙烯合成,上调PpSGR1表达进而抑制PpPSY转录水平,降低桃果实贮藏后期类胡萝卜素的合成能力。 相似文献
5.
以西瓜品种8424种子和幼苗为试材,利用人工气候室进行亚低温处理(昼/夜18℃/12℃)20 d,研究外源褪黑素(MT)和Ca2+浸种处理对亚低温条件下西瓜种子萌发,西瓜幼苗抗氧化酶SOD、POD和CAT等活性,渗透调节物质可溶性糖和脯氨酸含量的影响。结果表明,亚低温处理的西瓜种子发芽率和发芽势仅为46.5%和40.5%,外源100μmol·L-1褪黑素和5 mmol·L-1Ca2+复合浸种处理西瓜种子发芽率和发芽势分别达到62.3%和58.5%。外源褪黑素和Ca2+浸种处理显著提高了抗氧化酶SOD、POD、CAT和APX活性,促进了渗透调节物质可溶性糖和脯氨酸的积累,有效缓解亚低温对西瓜种子萌发和幼苗生长影响;褪黑素和Ca2+复合浸种西瓜幼苗在出苗第20天时植株鲜质量达到8.21 g·株-1,达到对照处理的85.5%。综上,外源褪黑素和Ca2+能通过提高西瓜幼苗抗氧化酶活性和渗透调节能力等,缓解亚低温的不良影响,促进西瓜幼苗生长。 相似文献
6.
钙对淹水胁迫下辣椒幼苗根系生长和呼吸代谢的影响 总被引：7，自引：0，他引：7
以‘花溪’辣椒(Capsicum annuum L. ) 为试材, 研究淹水胁迫不同时间( 0、3、6、9、12
d) , Ca2 +对辣椒幼苗根系生长和呼吸代谢相关酶活性的影响。结果表明: 外源Ca2 +浸种处理对淹水胁迫下幼苗的伤害有显著的缓解效应, 可改善根系的生长状况, 根系总长度、总表面积、体积、根尖数和平均直径等都显著高于单纯淹水胁迫; 与单纯淹水胁迫相比, 外源Ca2 +处理能够提高根系活力, 降低根系电解质渗出率, 提高ADH活性, 降低LDH活性, 避免乳酸和乙醛的积累, 同时使根系保持较高的MDH和SDH活性, 进行一定的有氧呼吸代谢。以上结果表明, 外源Ca2 +可通过调节辣椒幼苗根系内呼吸代谢来缓解淹水胁迫对植株的伤害。 相似文献
7.
不同栽培密度和钾钠离子处理对基质培番茄产量与品质的影响 总被引：1，自引：0，他引：1
以优质番茄品种京采6 号为试材,研究了不同栽培密度（3.8、5.0 株 · m-2）与离子处理（K+、Na+）对基质培番茄生长、产量与品质的影响,构建了番茄果实品质综合评价指数TQI。结果表明：提高营养液中的K+ 浓度,能够在不影响产量的同时增加番茄第2 穗果实可溶性糖、可溶性固形物、糖酸比和VC 含量;栽培密度对番茄产量和品质的影响较小;栽培密度× 离子互作显著影响了第1 穗果实有机酸、亚硝酸盐含量与糖酸比;第2 穗果是生产高品质番茄的关键,其在3.8 株 · m-2与高K+ 营养液条件下可获得最高的TQI。综合来看,建议在实际生产中控制栽培密度为3.8 株 · m-2,同时采用高K+ 营养液灌溉,可在稳产条件下获得高品质番茄。 相似文献
8.
以抗青枯病茄子自交系‘E-31’为材料,利用病毒诱导的基因沉默（virus induced gene silencing,VIGS）技术沉默抗病材料中调控抗病相关的信号基因,研究其在茄子抗青枯病反应中的作用。qRT-PCR结果表明,与对照植株相比,VIGS诱导基因沉默植株,目的基因的表达量均下降。MAPK级联途径相关基因MKK2和MAPK6,SA途径中的信号基因PAD4、NPR1、SGT1、TGA和GluA,以及WRRY转录因子基因WRKY70沉默,接种青枯雷尔氏菌（Ralstonia solanacearum）后植株出现不同程度的枯萎,而对照植株无变化。MAPK级联途径相关基因MAPK3和MAPK4,SA途径中的信号基因NDR1,ET途径中的信号基因EIN2和EIL1,JA途径信号基因JAR1沉默后,植株均未出现萎蔫症状。研究结果表明,MKK2、MAPK6、PAD4、NPR1、SGT1、TGA、GluA和WRKY70等基因在茄子调控抗青枯病反应中起正调控作用,而MAPK3、MAPK4、NDR1、EIL1、EIN2和JAR1等基因可能未参与或起负调作用,推断茄子‘E-31’调控青枯病信号途径可能主要依赖于SA途径。 相似文献
9.
为探究微塑料与重金属对农作物的影响,选取番茄作为受试植物,研究粒径为50 nm的聚苯乙烯纳米塑料(NPs)与Cu2+单独或复合污染对种子萌发和幼苗生长的影响。结果表明,与对照相比,NPs单独胁迫对番茄种子的萌发表现为低促中抑高恢复的影响,显著提高番茄幼苗的可溶性蛋白含量(250 mg·L-1处理除外),可溶性糖含量表现为低浓度(ρ,后同)(50 mg·L-1)降低、中浓度(100、250 mg·L-1)升高、高浓度(500、1000 mg·L-1)再降低的变化趋势。Cu2+单独胁迫下,番茄种子的发芽势、活力指数、平均发芽速度均低于对照,发芽指数仅在400 mg·L-1最高浓度组显著降低;Cu2+胁迫显著降低番茄幼苗的芽长、鲜质量、含水量和可溶性糖含量(50 mg·L-1处理除外),显著提高可溶性蛋白含量。NPs与Cu2+复合污染的结果表明,NPs进一步降低Cu... 相似文献
10.
【目的】CDPKs是植物中广泛存在的Ca2+感受器,鉴定刺梨(Rosa roxburghii Tratt.)CDPK基因家族成员,并探索其对不同供钙水平的表达响应。【方法】采用生物信息学方法鉴定并分析Rr CDPK基因家族,通过转录组测序及实时荧光定量PCR(real-time quantitative PCR,q RT-PCR)分析其组织表达特异性及在不同供钙水平下的表达响应。【结果】从刺梨基因组中共鉴定出16个具丝氨酸/苏氨酸蛋白激酶和EF-hand结构域的CDPK基因(命名为Rr CDPK1～16),结构分析显示蛋白长度在393～561 aa之间,分子质量在44.02～62.98 ku之间,平均等电点6.05;家族基因结构差别较大,外显子数量为2～10个,包括6个保守基序;亚细胞定位预测Rr CDPKs在细胞核和多种细胞器均有定位,主要定位于细胞质;进化分析可分为4个亚族,且与草莓的亲缘关系最近,其次是苹果,较远为拟南芥和水稻。启动子顺式作用元件分析表明,Rr CDPKs大多含光响应元件、多种激素响应元件及胁迫响应元件等。不同器官及果实发育时期的转录组数据显... 相似文献
11.
AIM:We examined the effect of interleukin-2 (IL-2) on calcium handling of rat cardiomyocytes. METHODS:The effects of steady state and transient changes in stimulus frequency on the intracellular calcium transient were investigated in the isolated ventricular myocytes with spectrofluorometry technique. RESULTS: Under the steady state (0.2 Hz), IL-2 at 2×105U/L decreased the peak [Ca2+] i and amplitude of the [Ca2+]i transient, increased the diastolic calcium level, and prolonged the decay of the calcium transient. At 1.25 mmol/L of extracellular [Ca2+], when increasing the stimulus frequency from 0.2 to 1.0 Hz, diastolic calcium level and peak [Ca2+] i as well as the amplitude of the transient were increased. The positive frequency relationship was blunted in the IL-2-treated myocytes and this was not normalized by increasing extracellular [Ca2+] to 2.5 mmol/L. The caffeine induced Ca2+ release was increased with increase in stimulus frequency. IL-2 inhibited the frequency relationship of caffeine induced Ca2+ release. The restitution was not different between control and IL-2 groups at the 1.25 mmol/L of extracellular [Ca2+], which was slowed in IL-2-treated myocytes when the extracellular [Ca2+] was increased to 2.5 mmol/L. CONCLUSIONS:It is concluded that the blunted frequency response of IL-2-treated myocytes was resulted from the decrease in SR Ca2+ release, which was related to depression of SR function. Despite the evidence of depressed SR Ca2+ uptake, the restitution of calcium transient at 1.25 mmol/L of extracellular remains unchanged, which maybe due to the increase in the Na+/Ca2+ exchanger activity. 相似文献
12.
LIU Xiao-ni CAO Dong-qing ZHANG Na-na TAO Ran DING Ying-jiong JIN Hui-ming LU Ning 《园艺学报》2016,32(12):2133-2138
AIM: To investigate the role of reactive oxygen species (ROS) in the regulation of intracellular Ca2+ induced by angiotensin II (Ang II) in the primarily cultured medullary neurons. METHODS: Primarily cultured medullary neurons were prepared from 14-day-old embryos of Sprague-Dawley rats in the study. The identification of medullary neurons was assessed by double-labeling immunofluorescence. To explore the role of ROS, mainly the superoxide (O2·), the O2·generation was measured using the fluorogenic probe dihydroethidium (DHE). To determine intracellular free calcium concentration ([Ca2+]i), the neurons were loaded with the Ca2+-specific dye Fura-2/AM. The cell viability after adding Ang II was also examined using CCK-8 assay. RESULTS: Most of the cultured cells were medullary neurons, more than 80% of which were glutamate positive neurons. Ang II (5 μmol/L) increased the level of ROS within 10 min in the medullary neurons. Ang II at 5 μmol/L induced a significant[Ca2+]i increase in the medullary neurons, and the effect of Ang II occurred rapidly and reached a peak within 20 min after administration. The level of[Ca2+]i started to decline after washout. The Ca2+ elevation induced by Ang II was significantly decreased by apocynin or TEMPOL. No significant difference in the cell viability between control group and 5 μmol/L Ang II treatment group was observed. CONCLUSION: ROS is involved in the regulation of[Ca2+]i induced by Ang II in the primarily cultured medullary neurons, suggesting a potential intracellular signaling mechanism involved in the Ang II-mediated oxidant regulation of central neural control of blood pressure. 相似文献
13.
AIM: The changes of myocardial nuclear membrane Ca2+ -ATPase function was investigated in ischemia/reperfusion injury. METHODS: The model of myocardial ischemia/reperfusion injury was established in rats. Myocardial nuclei were purified with sucrose density centrifugation, the activity of Ca2+ -ATPase was measured and calcium uptake was assayed with [45 Ca2+ ] . RESULTS: Plasma levels of malondialdehyde (MDA) and free fatty acid (FFA) in myocardial ischemia/reperfusion injury increased significantly( P<0.01 vs control). Ca2+ -ATPase activity and [45 Ca2+ ] uptake was lower than normal at below 10 μmol/L, while higher at 50 μmol/L. CONCLUSION:These data indicate dysfunction of nuclear menbrane calcium pump and [45 Ca2+ ] uptake function in myocardial ischemia/reperfusion injury. 相似文献
14.
AIM: To investigate the alteration of sarcoplasmic reticulum (SR) Ca2+ transport proteins including sarcoplasmic reticulum Ca2+-ATPase 2a(SERCA2a) and phospholamban(PLB) mRNA expression as well as the alteration of myocardial SR Ca2+-ATPase activity in neonatal hypothyroid rats, and to explore the effect of levothyroxine(L-T4) substitution therapy on the above indexes.METHODS: Hypothyroidism was induced by the administration of propylthiouracil (PTU, 50 mg/d) to the pregnant SD rats by gavage beginning on embryonic day 15 and continuing throughout the lactational period. A subgroup of neonatal hypothyroid rats were intraperitoneally injected with L-T4 levothroxine (20 μg/kg BW daily), starting from the day of birth. Other pregnant SD rats received normal saline instead of PTU. The samples of the rats in all 3 groups were harvested at postnatal day 3, 5 and 7 respectively (n=10). After measurement of serum thyroid hormone levels, the hearts were removed and the ventricles were weighed (HW). The concentration of calcium in ventricular myocardium(ventricular myoCa2+) was detected by fluorospectrophotometry and the activity of SR Ca2+-ATPase was determined by the inorganic phosphorus method. The mRNA expression of SERCA2a and PLB was also detected by real-time PCR. RESULTS: Neonatal hypothyroid rats had a significant lower level of SERCA2a mRNA (P<0.05) and a higher level of PLB mRNA (P<0.01), and subsequent lower SERCA2a/PLB at each postnatal day (P<0.01) was observed. Compared with hypothyroid group, the mRNA expression of SERCA2a significantly increased (P<0.05) and that of PLB significantly decreased (P<0.05) in L-T4 treatment group. The concentration of ventricular MyoCa2+ in hypothyroid group was significantly higher than that in control group (P<0.01), and that in L-T4 treatment group showed a significant decrease as compared with hypothyroid group (P<0.05). The activity of sarcoplasmic reticulum Ca2+-ATPase in hypothyroid group was significantly lower than that in control group (P<0.01), and that in L-T4 treatment group showed a significant increase as compared to hypothyroid group (P<0.05). CONCLUSION: The deficiency of thyroid hormone, resulting in decreased expression of SERCA2a mRNA as well as increased PLB mRNA, contributes to the reduction of SR Ca2+-ATPase activity in neonatal rats. This may be one of the most important mechanisms of myocardial systolic and diastolic dysfunctions. 相似文献
15.
AIM: To investigate the effect of interleukin-2(IL-2) on the intracellular calcium in electrically stimulated adult rat ventricular myocytes during anoxia and reoxygenation. METHODS: The isolated cardiac ventricular myocytes were exposed to 5 min anoxia followed by 10 min reoxygenation. Chemical anoxia was introduced by Krebs-Henseleit(K-H) solution containing 10-3 mol/L sodium dithionite. The spectrofluorometric method was used to verify intracellular calcium transient with fura-2/AM as calcium fluorescence probe. RESULTS: It was shown that during anoxia, the amplitude of Ca2+ transient was decreased, diastolic [Ca2+]i, time to peak and time to relaxation of Ca2+ transient were increased. All the parameters were got back but did not returned to the pre-anoxia level during reoxygenation. IL-2 at 2×105 U/L administrated during anoxia aggravated the effect of rexoxygenation on [Ca2+]i transient. Pretreatment with a specific κ opioid antagonist, nor-BNI(10-8 mol/L), abolished the effect induced by IL-2 during anoxia on the [Ca2+]i transients, whereas specific δ opioid antagonist, naltrindole(10-6 mol/L), did not cancel the effect. CONCLUSION: It is concluded that administration of IL-2 during anoxia aggravated the effect of reoxygenation on the [Ca2+]i transients of isolated ventricular myocytes, which was mediated by cardiac κ opioid receptor pathway. 相似文献
16.
AIM: To investigate the role of potassium channels in the regulation of intracellular free calcium concentration ( [Ca2+]i) of pulmonary artery smooth muscle cells (PASMCs) in rats. METHODS: The fluorescence Ca2+ indicator Fura-2/AM was used to observe [Ca2+]i of rat PASMCs in normal and chronic hypoxic condition. The influences of potassium channels on PASMCs proliferation were assessed by MTT assay. RESULTS: 1. In normoxic condition, [Ca2+]i was (156.91±8.60) nmol/L, and in hypoxic condition, [Ca2+]i was (294.01±16.81) nmol/L. 2. In normoxic condition, the voltage-dependent K+-channel antagonist 4-aminopyridine (4AP), but not the Ca2+-activated K+-channel antagonist tetraethylammonium (TEA) and the ATP-sensitive K+-channel antagonist glibenclamide (Glib) increased [Ca2+]i. 3. In hypoxic condition, 4AP and TEA caused the rise in [Ca2+]i , but Glib had no effect on [Ca2+]i. 4. MTT assay showed that 4AP increased the value of absorbing light degree (A value) in normoxic and hypoxic condition (0.582±0.062,0.873±0.043,respectively, P＜0.01), TEA increased A value only in hypoxic condition, and Glib had no effect on the proliferation of PASMCs. CONCLUSIONS: KV plays an important role in the regulation of [Ca2+]i and proliferation of PASMCs. KCa serves as distinct responsive roles in the regulation of proliferation of PASMCs in hypoxic condition. KATP has no effect on [Ca2+]i and proliferation of PASMCs in normoxic and hypoxic conditions. 相似文献
17.
AIM:These studies aimed at exploring the alteration of intracellular Ca2+ level in the course of macrophage-derived foam cell formation as well as its mechanism.METHODS:Foam-like cell was generated by peritoneal macrophage of C57BL/6J mouse, which is susceptible to atherosclerosis, incubated in 10 mg·L-1 oxidized low density lipoprotein for 96 hours. With the technique of Ca2+ fluorescent indicator and the assay of NADH-oxidizing coupling spectrum-alteration, the intracellular Ca2+ level and membranous Ca2+-ATPase activity of the above foam-like cell were determined.RESULTS:The foam-like macrophage Ca2+ level was 2.7 times higher than the control macrophage, and the former Ca2+-ATPase activity was 24% of the later.CONCLUSION:The results suggested that macrophage-derived foam cell formation was connected with slow Ca2+ entry or release, which possibly derived from long-lasting opening of membranous Ca2+ channels at the early stage and irreversible inactivating of membranous Ca2+ pump at the late stage. 相似文献
18.
AIM:To investigate the effect of Ba2+ concentration on L-type of Ca2+ channel in hypothalamic neurons.METHODS:The cell acute isolation technique and cell-attached patch-clamp technique were used.RESULTS:The slope conductance of L-type Ca2+ channel were 28.6 pS (110 mmol/L) and 19.1 pS (10 mmol/L), and the open probability (NP0) obviously different with different Ba2+ concentration as carrier. CONCLUSION:Ba2+ concentration had the obvious effect on the L-type Ca2+ channel. 相似文献
19.
AIM:To explore the molecular mechanism of Radix Ophioponis against vascular endothelial cell (VEC) apoptosis induced by LPS.METHODS:The apoptosis of human umbilical vascular endothelial cells(HUVEC) was induced by lipopolysaccharide(LPS). The influence of Radix Ophiopogonis on the expression of bcl-2 and intracellular Ca2+ was detected by flow cytometry and laser confocal microscope.RESULTS:The serum containing Radix Ophiopogonis suppressed the increase in bcl-2 expression and overloading of Ca2+ induced by LPS in HUVEC.CONCLUSION:The mechanism of Radix Ophiopogonis against HUVEC apotosis may be related with its regulatory effect on bcl-2 expression and remission of Ca2+ overloading. 相似文献