植物过氧化物酶研究进展

过氧化物酶 [peroxidase,POD,EC1 .1 1 .1 .7(X) ]是广泛存在于各种动物、植物和微生物体内的一类氧化酶。催化由过氧化氢参与的各种还原剂的氧化反应 :RH2 H2 O2 →2 H2 O R。植物过氧化物酶的研究可追溯到 1 80 9年用愈创树脂为底物进行的颜色反应。但直到一个世纪之后才开展此酶的分离和命名。已知的催化反应底物超过 2 0 0种 ,以及多种过氧化物和辅助因子。迄今被研究最深入的应首推辣根过氧化物酶 (horseradish pero-xidase,HRP)。早在 1 94 0年 ,Thorell即用电泳方法从部分纯化的辣根组织中区分出 2种不同的 HRP,之后此酶…  

铜尾矿对小麦生长发育和生理功能的影响

通过盆栽实验，分析了铜陵铜尾矿对小麦生长发育和生理功能的影响。结果表明，小麦种子能在铜尾矿上萌发，但发芽率和发芽速率均小于正常土壤中播种的小麦，高比例尾矿抑制小麦的株高，尾矿降低叶绿素含量，但对叶绿素a/b无影响，与对照组相比，尾矿组根系表现为变短变粗，须根数减少，尾矿能增加小麦根和茎叶部分生物量，且能明显提高根冠比，在尾矿胁迫下，小麦叶片的细胞膜透性和游离脯氨酸含量随尾矿比例增加而增大，可作为鉴定植物相对抗性的指标。  

生物体内γ-氨基丁酸的研究

γ 氨基丁酸在生物体内广泛存在 ,是中枢神经系统内重要的抑制性神经递质。本文对其生理活性功能 ,应用 ,检测方法进行了论述。  

DHA和EPA的研究现状与趋势

本文综述了DHA和EPA的研究背景、生物体内的代谢、生理作用及开发应用,并据此提出今后进一步开展该方面研究的方向。  

Regulation and function of somatostatin receptors

This review summarizes the latest advances that have been made to elucidate the somatostatinergic system in respect to somatostatin receptor evolution, the development of receptor agonists/antagonists, receptor regulation, signal transduction, effects on cell proliferation, receptor-receptor or receptor-protein interactions and receptor function.  

Nitric oxide and nitric oxide synthase activity in plants

Research on NO in plants has gained considerable attention in recent years mainly due to its function in plant growth and development and as a key signalling molecule in different intracellular processes in plants. The NO emission from plants is known since the 1970s, and now there is abundant information on the multiple effects of exogenously applied NO on different physiological and biochemical processes of plants. The physiological function of NO in plants mainly involves the induction of different processes, including the expression of defence-related genes against pathogens and apoptosis/programmed cell death (PCD), maturation and senescence, stomatal closure, seed germination, root development and the induction of ethylene emission. NO can be produced in plants by non-enzymatic and enzymatic systems. The NO-producing enzymes identified in plants are nitrate reductase, and several nitric oxide synthase-like activities, including one localized in peroxisomes which has been biochemically characterized. Recently, two genes of plant proteins with NOS activity have been isolated and characterized for the first time, and both proteins do not have sequence similarities to any mammalian NOS isoform. However, different evidence available indicate that there are other potential enzymatic sources of NO in plants, including xanthine oxidoreductase, peroxidase, cytochrome P450, and some hemeproteins. In plants, the enzymatic production of the signal molecule NO, either constitutive or induced by different biotic/abiotic stresses, may be a much more common event than was initially thought.  

高等植物中维生素C的功能、合成及代谢研究进展

植物体内合成的维生素C在植物抗氧化和自由基清除、光合作用和光保护、细胞生长和分裂以及一些重要次生代谢物和乙烯的合成等方面具有非常重要的生理功能.维生素C的生物合成途径及其代谢调控的基因工程研究最近取得了突破.  

鞣花酸的生理功能及工艺开发研究现状

综述了鞣花酸的防癌，抗癌作用及其机理，同时对它的抗人体免疫缺陷病毒，抗氧化，凝血、降压、镇静等作用也作了论述，并对其生产工艺作了简单介绍。  

土壤有效硅对大豆生长发育和生理功能的影响

人工调节土壤有效硅含量及盆栽试验，研究土壤有效硅对大豆生长发育和生理功能的影响。结果表明，土壤有效硅含量在55．1～202.8mg·kg^-1范围内，随着土壤有效硅含量的提高，大豆种子萌发过程中蛋白酶和脂肪酶活性升高，淀粉酶活性无显著变化，呼吸速率加快，种子活力升高，萌发速度加快，种子萌发率无显著变化；幼苗生长过程中叶片叶绿素含量无显著变化，光合速率加快，根系活力、硝酸还原酶活力升高，蒸腾强度减弱，水分利用效率和叶含水量升高，抗旱保水能力提高。大豆幼苗含硅量与土壤有效硅含量呈线性正相关趋势(r=0．994)。土壤有效硅含量大于2028mg·kg^-1，生理功能不再显著变化，说明土壤中的硅被大豆吸收后，改善了大豆萌发种子和幼苗的生理功能，使种子萌发和幼苗生长加快。  

DHA和EPA的生理功能及其应用

综述了DHA和EPA的分布、生理功能及应用；并提出了存在的问题。