兰光对蚕豆气孔运动的影响

蚕豆(Vicia faba L.)下表皮条上的气孔复合体对白光、兰光和二氧化碳浓度的反应与培养介质中KCl浓度有关。在10mM中,气孔复合体对兰光和二氧化碳浓度的反应很敏感。兰光下气孔的开度比白光下大,而且气孔的张开运动是不依赖CO_2浓度的。本文还讨论了白光、兰尤和CO_2对气孔复合体的可能作用机理。     

蓝光调节气孔运动的信号途径及其与脱落酸相互关系研究

气孔运动与植物水分代谢密切相关.保卫细胞可有效感知和整合多种环境信号,通过控制离子进出调节其膨压,影响气孔开与闭.诸多研究表明,蓝光信号诱导气孔开放和逆境信号脱落酸(ABA)促进气孔关闭构成了气孔运动的两大研究领域.该文就保卫细胞中蓝光信号传递及与ABA信号交叉控制气孔开闭的研究进展进行综述,以了解气孔对蓝光和ABA反应的最新进展,为发展耐旱与提高作物水分利用效率生物技术的改进提供理论支持.     

植物激素对植物器官脱落的调节实验的改进

以大叶黄杨叶柄为外植体材料，采用含有激素的琼脂块代替注射激素液滴的处理方法，将植物激素对植物器官脱落的影响实验进行了改进。     

外源过氧化氢对蚕豆气孔运动的影响

运用外源过氧化氢(H2O2)处理、光镜观察的方法研究了H2O2对蚕豆气孔运动的影响．结果表明，H2O2诱导气孔关闭的最适浓度和最佳时间分别为100μmol／L和3h．H2O2促进气孔关闭的作用可被抗坏血酸和过氧化氢酶(CAT)逆转．还就内源H2O2在光、暗调控的气孔运动中的作用进行了讨论．     

气孔运动机制的研究进展

气孔运动的机理一直引起人们的注意不是没有道理的。因为气孔是植物进行气体交换的重要“门户”。特别有趣的是植物可以通过某种机制来控制自己气孔开张的程度。这样一方面它可以保证在光合作用中得到充足的CO_2原料供给,又不致在高温和缺水条件下,因气孔的不适宜开放引起水分的过度散失。我们了解和掌握气孔运动的规律对调节和控制植物的光合作用、蒸腾作用,使植物获得良好协调的生长是十分重要的。     

地钱气孔运动的进一步观察

用光导纤维冷光源表面照明，在显微摄像系统下观察到活体的风兜地钱（ＭａｒｃｈａｎｔｉａｐａｌｅａｃｅａＢｅｒｔｏｌ．ｖａｒ．ｄｉｐｔｅｒａ（Ｍｏｎｔ．）Ｈａｔｔ．）的气孔运动．观察结果表明，围成烟突状的气孔的下部乳凸瓣膜形细胞，随水分状态运动，从而使气孔启闭     

植物激素与蔗糖对甘薯愈伤组织淀粉酶活性的调节

甘薯（Ipomoea batatas Lam）在自然栽培条件下,只有块根内有一种淀粉酶（β-淀粉酶）的表达,其余器官中几乎检测不到淀粉酶存在．而在甘薯愈伤组织中,有两种α-淀粉酶和两种β-淀粉酶表达,这些淀粉酶与已报道的α-淀粉酶和甘薯块根的β-淀粉酶在性质上都存在差异．     

运动中激素对糖代谢的调节

本文简析了静息、运动时，运动后恢复期几种地糖代谢的调控，认为，机体糖、脂肪、氨基酸代谢的变化主要取决于胰岛素和胰高血压糖素的比例，胰岛素是体内唯一降血糖并同时促进糖原、脂肪、蛋白质合成的激素。胰高血糖素、糖皮质激素、肾上腺素等则通过不同的机制促进糖异生，增加糖原分解，升高血糖，有训练者运动时释放的调节糖代谢的激素数量少于无训练者。     

运动对骨骼影响的激素调节

通常认为运动对骨骼产生正面的影响,但运动过量会对骨骼产生不良的影响。运用文献综述、归纳演绎等研究方法,论述了运动对骨产生的影响及其激素调节的实现途径。     

Inhibition of shoot branching by new terpenoid plant hormones

Shoot branching is a major determinant of plant architecture and is highly regulated by endogenous and environmental cues. Two classes of hormones, auxin and cytokinin, have long been known to have an important involvement in controlling shoot branching. Previous studies using a series of mutants with enhanced shoot branching suggested the existence of a third class of hormone(s) that is derived from carotenoids, but its chemical identity has been unknown. Here we show that levels of strigolactones, a group of terpenoid lactones, are significantly reduced in some of the branching mutants. Furthermore, application of strigolactones inhibits shoot branching in these mutants. Strigolactones were previously found in root exudates acting as communication chemicals with parasitic weeds and symbiotic arbuscular mycorrhizal fungi. Thus, we propose that strigolactones act as a new hormone class-or their biosynthetic precursors-in regulating above-ground plant architecture, and also have a function in underground communication with other neighbouring organisms.     

Muscarinic acetylcholine receptor is involved in acetylcholine regulating stomatal movement

In animal cells, action of acetylcholine depends on its binding with its two specific receptors on the plasma membrane: the nicotinic and muscarinic respectively. The present investigation has shown that agonists of muscarinic receptor (muscarine) could induce stomatal opening, while the antagonists (atropine) could block stomatal opening induced by acetylcholine. Their effects can only be realized in medium containing Ca²⁺, but not in medium containing K⁺. The results tend to reveal that the muscarinic receptor is involved in acetylcholine-induced stomatal movement.     

pH induced elastic modulus of guard cell wall in stomatal movement

Guard cell wall properties are important in stomatal movement. Previous research focused on the structure and anatomy of guard cell walls, but little is known about the physical changes that take place within the walls during stomatal opening and closure. In this work, we investigate the volumetric elastic modulus (ε) of the guard cell wall at different pH values during stomatal opening in Vicia faba epidermal strips using a cell pressure probe. The volumetric elastic modulus of the guard cell wall decrease...     

Regulation of the inward K+-channels in stomatal guard cells by cytoskeletal microtubules

Patch clamp techniques were applied to investigating the regulation of the inward K⁺-channels inVicia stomatal guard cells by cytoskeletal microtubules. The intracellular addition of either microtubule-disassembling reagent amprophos-methyl (APM) or microtubule-stabilizing reagent taxol resulted in significant inhibition of the inward K⁺-currents across the plasma membranes ofVicia stomatal guard cells. The results suggest that the activation of the inward K⁺-channels in stomatal guard cells requires proper dynamic organization of cytoskeletal microtubules. The regulation of the inward K⁺-channels in guard cells by microtubules may mediate the regulation of stomatal movements by cytoskeleton.     

Regulation of cell movement is mediated by stretch-activated calcium channels.

Intracellular calcium regulates many of the molecular processes that are essential for cell movement. It is required for the production of actomyosin-based contractile forces, the regulation of the structure and dynamics of the actin cytoskeletons, and the formation and disassembly of cell-substratum adhesions. Calcium also serves as a second messenger in many biochemical signal-transduction pathways. However, despite the pivotal role of calcium in motile processes, it is not clear how calcium regulates overall cell movement. Here we show that transient increases in intracellular calcium, [Ca2+]i, during the locomotion of fish epithelial keratocytes, occur more frequently in cells that become temporarily 'stuck' to the substratum or when subjected to mechanical stretching. We find that calcium transients arise from the activation of stretch-activated calcium channels, which triggers an influx of extracellular calcium. In addition, the subsequent increase in [Ca2+]i is involved in detachment of the rear cell margin. Thus, we have defined a mechanism by which cells can detect and transduce mechanical forces into biochemical signals that can modulate locomotion.     

Progress in quantitative analysis of plant hormones

Plant hormones are small molecular natural products that regulate all plant developmental processes at low concentrations. Quantitative analysis of plant hormones is increasingly important for in-depth study of their biosynthesis,transport,metabolism and molecular regulatory mechanisms. Although plant hormone analysis remains a bottleneck in plant scientific research owing to the trace concentrations and complex components in plant crude extracts,much progress has been achieved in the development of extraction,purification and detection techniques in recent years. Solid phase extraction and chromatography/mass spectrometry have been applied widely for purification and quantitative analysis of plant hormones owing to their high selectivity and sensitivity. Purification methods such as liquid partition and immunoaffinity chromatography,and detection methods including immunoassay and electrochemical analysis,are employed. The advantages and disadvantages of these methods are discussed. In situ,real-time and multi-plant hormone profiling will comprise mainstream techniques for quantitative analyses in future studies on the regulatory mechanisms and crosstalk of plant hormones.     

Progress in quantitative analysis of plant hormones

Plant hormones are small molecular natural products that regulate all plant developmental processes at low concentrations. Quantitative analysis of plant hormones is increasingly important for in-depth study of their biosynthesis, transport, metabolism and molecular regulatory mechanisms. Although plant hormone analysis remains a bottleneck in plant scientific research owing to the trace concentrations and complex components in plant crude extracts, much progress has been achieved in the development of extraction, purification and detection techniques in recent years. Solid phase extraction and chromatography/mass spectrometry have been applied widely for purification and quantitative analysis of plant hormones owing to their high selectivity and sensitivity. Purification methods such as liquid partition and immunoaffinity chromatography, and detection methods including immunoassay and electrochemical analysis, are employed. The advantages and disadvantages of these methods are discussed. In situ, real-time and multi-plant hormone profiling will comprise mainstream techniques for quantitative analyses in future studies on the regulatory mechanisms and crosstalk of plant hormones.