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本文对近年植物叶片衰老过程中叶绿素降解代谢研究进展作一介绍,包括叶绿素降解产物分离、检测和命名;叶绿素降解途径及降解酶系。此外,对叶绿素降解意义及今后研究趋势进行了评述。 相似文献
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植物叶片衰老过程中叶绿素降解代谢研究进展 总被引:3,自引:0,他引:3
本文对近年来植物叶片衰老过程中叶绿素降解代谢研究进展作一介绍,包括叶绿素降解产物分离、检测和命名;叶绿素降解途径及降解酶系。此外,对叶绿素降解意义及今后研究趋势进行了评述。 相似文献
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高等植物叶绿素生物合成的研究进展 总被引:23,自引:1,他引:22
叶绿素是植物叶绿体内参与光合作用的重要色素,其功能是捕获光能并驱动电子转移到反应中心.整个叶绿素生物合成过程(L-谷氨酰-tRNA→叶绿素a→叶绿素b)需要15步反应,涉及15种酶,迄今在模式植物拟南芥中已分离到27个编码这些酶的基因,完成了以拟南芥为代表的被子植物叶绿素生物合成全部基因的克隆.本文主要对近年来国内外有关植物叶绿素的生物合成过程及相关酶基因的克隆、生物合成途径中2个关键步骤(σ-氨基酮戊酸(ALA)合成和Mg离子插入原卟啉Ⅸ的调节)、影响叶绿素生物合成的主要因素(光、温度、营养元素等),以及叶绿素生物合成相关酶的其他生物学功能等的研究进展进行综述. 相似文献
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为了分析叶绿素酶在叶绿素降解过程中的作用,构建了抑制AfCLH1和/或AtCLH2的拟南芥RNM株系。在RNAi株系中,叶绿素酶的表达和活性都被显著抑制。然而,无论是在正常生长情况下还是在黑暗诱导的衰老进程中,RN加株系中的叶绿素降解速率与野生型中的相比均无显著差异。进一步的分析结果表明,AtCLH1 RNAi株系中的叶绿素a/b比值在叶片衰老进程中逐渐降低,而野生型中的却逐渐升高。另外,还观察到所有株系中叶绿素酶的活性在黑暗诱导的衰老过程的初期均呈现出上升的趋势。与这一变化趋势正好相反,在所有株系中,叶绿素酶基因的表达在黑暗诱导衰老后就开始大幅下降。有趣的是,与野生型相比,RNAi株系中的目标叶绿素酶基因仍然维持在一个较低的表达水平。这说明拟南芥中可能存在一个反馈补偿机制。基于这些结果,并结合相关的研究报道,认为叶绿素酶很可能参与了衰老进程早期的叶绿素b向a的转换过程。 相似文献
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叶绿素酶研究的新进展 总被引:2,自引:0,他引:2
叶绿素酶催化叶绿素水解生成脱植醇叶绿素,是叶绿素降解中的关键酶之一。本文从叶绿素酶的基因克隆出来,就近年来在该酶的基因表达调控,细胞内定位,同功酶性质以及糖基化作用等方面的进展做了简要综述。 相似文献
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绿色器官衰老进程中叶绿素降解代谢及其调控的研究进展 总被引:2,自引:0,他引:2
褪绿(degreening)现象是绿色器官衰老的显著标志,其中涉及的叶绿素急速降解是植物衰老的特征性生理生化过程。近十余年来,叶绿素降解的主要生化途径(PAO途径)已基本被阐明。游离的叶绿素及其代谢中间产物具有潜在的光毒性,因此精准调控的叶绿素降解被认为是一个高效有序的解毒过程。目前关于叶绿素降解的全局性调控机制依然知之甚少;多个物种中叶绿素降解关键调控因子SGRs/NYEs的鉴别及其相关作用机理的初步揭示是该领域近年来的最显要进展。上述研究基础预示着近期在叶绿素降解调控的多个方向上可能会取得实质性乃至突破性进展。 相似文献
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In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980. 相似文献
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N. P. Vesselkin Yu. V. Natochin 《Journal of Evolutionary Biochemistry and Physiology》2010,46(6):592-603
Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms.
The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal
mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization
followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The
mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction
of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms
are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning
of physiological systems and organs of the living organism 相似文献