小麦颖果韧皮部细胞ATPase活性及其与籽粒光合同化物积累关系

 【目的】探明韧皮部细胞ATPase分布规律,分析韧皮部细胞ATPase活性与籽粒光合同化物量之间的关系。【方法】在小麦（Triticum aestivum L.）灌浆不同阶段,采用蒽酮法测定籽粒光合同化物积累量;运用显微细胞化学技术对颖果韧皮部和胚乳细胞的多糖进行定位,同时对韧皮部细胞ATPase进行超微细胞化学定位。对籽粒光合同化物积累量与韧皮部细胞ATPase活性产物量进行相关分析和线性回归分析。【结果】(1)在灌浆渐增期,籽粒积累的光合同化物主要是可溶性糖。约在花后14 d,籽粒可溶性糖和淀粉积累量含量相等。以后,籽粒以积累淀粉为主。在整个灌浆期,籽粒可溶性糖和淀粉量的变化呈现彼此消长,但籽粒总糖含量一直呈“S”型增长。在灌浆渐增期和快增期,韧皮部筛分子（Sieve element,SE）的细胞壁和胚乳细胞的淀粉粒均被锡夫试剂染成鲜红色;但在灌浆缓增期,上述细胞染色明显变浅。（2）在SE、中间细胞（Intermediary Cell,IC）、伴胞（Companion Cell,CC）和韧皮薄壁细胞（Phloem Parenchyma Cell,PPC）中,ATPase活性产物主要分布于质膜、细胞内壁和靠近质膜的囊泡上。在SE内的P型-质体和线粒体的双层膜上、SE和IC之间分枝状的胞间连丝上也有较强ATPase活性。在灌浆渐增期和快增期,SE的ATPase活性高,而在缓增期,IC的ATPase活性较SE高。（3）SE中ATPase酶活性产物与籽粒可溶糖呈显著负相关;与籽粒淀粉含量呈极显著正相关;与籽粒总糖呈显著正相关,且ATPase活性产物与光合同化物积累量之间有明显的线性关系。IC中ATPase活性产物只与籽粒可溶糖呈极显著正相关。【结论】在灌浆过程中,籽粒中可溶性糖和淀粉量的增加彼此消长,但总糖含量一直增加。籽粒光合同化物积累量与SE和IC中ATPase活性产物量之间有显著或极显著的相关关系。韧皮部细胞ATPase活性产物呈现出动态的时空变化。SE在灌浆前2个阶段起主要的同化物运输作用,而IC主要在灌浆第3阶段起主导作用。上述结果为小麦籽粒灌浆生理研究提供了细胞学基础。     

Dietary potassium requirement of juvenile grass carp (Ctenopharyngodon idella Val.) based on growth and tissue potassium content

A growth trial was conducted to estimate the optimum concentration of dietary potassium (K) for grass carp (Ctenopharyngodon idella). Triplicate groups of grass carp (3.96 ± 0.06 g) were fed diets containing graded levels (0.87, 2.90, 5.37, 7.54, 9.87 and 12.4 g kg^?1) of K for 8 weeks. Final body weight, weight gain and feed efficiency and gill Na⁺‐K⁺ ATPase activity were highest in fish fed with 9.87 g kg^?1 dietary K and lowest in fish fed the basal diet (P < 0.05). The K contents in whole body and muscle were linearly increased up to the 9.87 g kg^?1 dietary K and then levelled off beyond this level, whereas in scales and vertebrae up to the 7.54 g kg^?1 dietary K (P < 0.05). However, dietary K levels had no significant effect on ash, Ca, P and Mg contents in whole body, scales, vertebrae or muscle. Analysis using polynomial regression of weight gain and gill Na⁺‐K⁺ ATPase activity and using the broken‐line regression of whole body K concentrations indicated that the adequate dietary K concentration for grass carp is about 9.45–9.99 g kg^?1 diet.     

渗透胁迫对白三叶幼苗根系离子分泌和质膜ATP酶活性的影响

用PEG－6000渗透胁迫处理,白三叶根系质膜透性升高,抗旱品种‘海发’增幅小于不抗旱品种‘瑞文德’。根系分泌物中K+、Ca2+、H+的含量变化与根系质膜透性的变化一致。水分胁迫早期,白三叶根系PM H＋-ATPase活性升高,胁迫时间延长,不抗旱品种‘瑞文德’的PM H＋-ATPase酶活性下降,但抗旱品种‘海发’的酶活性一直较高。PM Ca2+-ATPase酶的活性与PM H＋-ATPase酶表现一致。     

敌百虫对大鼠肝细胞[Ca~(2+)]_i、ATP酶及GJIC的影响

通过给大鼠肝细胞培养液中加入敌百虫(染毒终质量浓度分别为0,2,10,50 mg/L),探讨敌百虫对肝细胞内钙离子([Ca2+]i)、Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性及间隙连接通讯(GJIC)的影响。结果显示,不同质量浓度敌百虫作用12 h,[Ca2+]i均极显著高于对照组(P0.01);随着染毒剂量的增加,Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性及GJIC均显著或极显著下降(P0.05或P0.01)。说明敌百虫对肝细胞有明显的毒性作用,GJIC的下调可能与Ca2+浓度的升高和Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性的下降有关。     

Ion flux kinetics in blue light‐grown field dodder (Cuscuta campestris) seedlings

Previous studies have revealed that blue light stimulates coiling and prehaustoria development in young de‐etiolated dodder seedlings prior to host attachment. In this study, the Ca²⁺ and H⁺ flux kinetics that are associated with blue light‐mediated coiling and prehaustoria development in de‐etiolated dodder seedlings were measured uninvasively using the ion‐selective, vibrating microelectrode ion flux system. The findings showed that blue light induces rapid transient changes in the net Ca²⁺ and H⁺ fluxes. A clearly pronounced lag of about several minutes was observed between the blue light‐induced changes in the Ca²⁺ and H⁺ fluxes, with H⁺ being a leading ion. The addition of 1 mol L^?1 vanadate, a known blocker of the plasma‐membrane H⁺‐ATPase, to the bathing solution completely prevented both the H⁺ and the Ca²⁺ flux responses and inhibited coiling and prehaustoria development, suggesting a causal relationship between the blue light‐induced changes in the net Ca²⁺ and H⁺ fluxes and seedling movements. It is concluded that the plasma‐membrane H⁺‐ATPase plays a key role in a dodder's parasitic mode of growth and its adaptive response to the environment.     

温度和乌苯苷对延边黄牛卵母细胞Na/K ATP酶活性的影响

通过研究温度和不同分级对延边黄牛卵母细胞Na/K ATP酶活性的影响,以及对其特异性抑制剂乌苯苷的敏感浓度,对延边黄牛卵母细胞Na/K ATP酶做初步探究,为进一步研究Na/K ATP酶活性与卵母细胞体外成熟的相关性打下良好基础.结果表明,延边黄牛卵母细胞的Na/K ATP酶活性在50℃达到最大值,在反应温度低于或高于50℃时酶的活性均降低,且在高于50℃时酶活急剧降低.乌苯苷浓度在2 mmol/L时孤雌卵母细胞完全停止卵裂.A级卵母细胞,裸卵和过成熟卵母细胞三者的Na/K ATP酶活性在统计学上差异不显著,但裸卵的Na/K ATP酶活性在数值上略高于其它两组.因此,延边黄牛卵母细胞的Na/K ATP酶的最适反应温度为50℃,其活力能够被2 mmol/L乌苯苷完全抑制,不同质量卵母细胞的Na/K ATP酶活性中,裸卵的Na/K ATP酶活性最高.     

洞庭青鲫等5个鲫品系线粒体ATPase基因序列的比较分析

运用PCR扩增、克隆、测序等技术对洞庭青鲫(Carassius auratus var.Dongtingking)、彭泽鲫(C.auratus var.Pengze)、普通鲫(C.auratus)、红鲫(C.auratus var.red)、日本白鲫(C.auratus cuvieri)等5个鲫品系线粒体DNA ATP...     

两种养殖模式下泥鳅养成品体色、质构及其脏器消化酶、抗氧化酶和ATP酶活力的差异

随机选取池塘专养模式(M1)和稻田养殖模式(M2)养成的平均体长和体重分别为(113.37±4.55) mm、(13.35±1.23)g和(122.69±5.22) mm、(16.43±1.36)g的1龄泥鳅(Misgurnus anguillicaudatus)作为实验对象,以养殖泥鳅的稻田鲜土样为色差对照(Mo),比较分析了2种模式下泥鳅间体色、背肌质构、脏器消化酶、抗氧化酶和ATP酶的差异,以期为阐述稻田生境下泥鳅生活策略、2种养殖模式下泥鳅的品质鉴定及其养殖模式的优化提供理论依据.结果显示:(1)M1泥鳅养成品背部体色与对照具有显著差异(P＜0.05),二者测量值呈Mo＞M1(P＜0.05);(2)所测背肌质构指标中,M1和M2均具显著差异(P＜0.05),除黏着性外,其余各指标测量值均呈M2＞M1 (P＜0.05);(3)所测消化酶中,M1和M2间仅蛋白酶和脂肪酶具有显著差异(P＜0.05),其测量值依次呈M2＞M1和M1＞M2 (P＜0.05);(4)所测脏器抗氧化酶和消化酶中,M1和M2间均具有显著差异(P＜0.05),各测量值均呈M2＞M1 (P＜0.05).     

狐胆汁对蟾蜍离体心脏功能的影响

目的：研究狐胆汁对蟾蜍离体心脏的作用及对蟾蜍离体心脏细胞膜ATP酶活性的影响。方法：采用离体蛙心灌流法观察狐胆汁对离体蟾蜍心脏的收缩力、心率的影响,并通过定磷法检测狐胆汁对离体蟾蜍心肌细胞膜ATP酶活性的影响。结果：狐胆汁使蟾蜍离体心脏的收缩力加强,在0.3～4.0g/L浓度范围内,狐胆汁促进心肌收缩力的作用与剂量之间呈量效关系,最大效应可使心肌收缩力提高390%,心率减慢。随狐胆汁浓度提高,心肌细胞膜Ca^2＋-ATP酶活性提高,Na^＋K^＋-ATP酶、Mg^2＋-ATP酶、Ca^2＋Mg^2＋-ATP酶活性下降。结论：狐胆汁能提高蟾蜍离体心脏的功能,其作用机制有待进一步研究。