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1.
茶叶片阶段性返白过程中色素蛋白复合体的变化   总被引:11,自引:0,他引:11  
用SDS-PAGE盘状电泳从温敏型阶段性返白的安吉白茶完全复绿叶中分离出2条叶绿素a蛋白复合物(CPⅠ)、2条叶绿素a/b捕光蛋白复合物(CPⅡ:LHCP1、LHCP2)和1条游离色素带,而全白期叶片中则未发现CPⅠ和CPⅡ,但有很少量CPⅡ的脱辅基蛋白和游离色素。此类叶片开始得绿时,CPⅠ、LHCP1和LHCP2同时出现,但寡聚形式(CPⅠa)的恢复稍迟些,各种色素蛋白复合体的含量均随绿逐步上升  相似文献   

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实验研究了莲种子(NelumbonuciferaGaertn.)在光下萌发过程中叶绿体色素蛋白复合体、多肽组成以及PSⅡ光化活性的变化。结果表明,萌发到第6天的莲胚芽叶绿体,在SDSPAGE凝胶柱中只分出两条色素带,分别为捕光叶绿素蛋白复合体(LHCⅡ)和自由色素(FP)。萌发到第8天的莲叶绿体可分出CPⅠ,LHCⅡ1、LHCⅡ和FP。仍未检测到PSⅡ反应中心复合物。多肽分析表明:未萌发和萌发到第2天的叶绿体中30kD多肽的含量显著,尽管27kD多肽在未见光时已开始合成,但其含量很少。随着照光时间增长,30kD多肽含量逐渐减少,27kD多肽的含量逐渐增多,到第12天时超过30kD多肽的含量。电子传递速率和室温荧光诱导动力学的测定表明:PSⅡ光化活性在莲子萌发到第7天时才开始出现,并随萌发时间增加而升高,与此同时Chla/b比值由低到高达到正常值。莲子在光下萌发过程中其叶绿体膜成分及膜功能的变化与它的超微结构的变化相符合。结果再次证明,莲胚芽叶绿体在光下的发育具有与其它高等植物所不同的独特途径,这为莲在被子植物系统发育中占有独特地位的看法提供了依据。  相似文献   

3.
低温下强光胁迫对小麦叶片光系统I结构与功能的影响   总被引:3,自引:0,他引:3  
探讨了低下强光胁迫对小麦(Triticum aestivum L.)扬麦5号苗期叶片(第三叶)类囊本膜上PSⅠ-200颗粒光化学特性和组分的影响。光胁迫条件下,PSⅠ-200颗粒的电子传递活性受到抑制,4℃条件下光胁迫的抑制程度低于25℃下的抑制,25℃条件下,光胁迫导致PSⅠ-200颗粒还原侧19kD及LHCⅠ等多肽降解;而4℃条件下,19kD保持稳定,但LHCⅠ等多肽在光胁迫处理过程中却发生降  相似文献   

4.
抽薹期叶绿素缺乏油菜突变体类囊体膜的研究   总被引:10,自引:0,他引:10  
以抽薹期野生型油菜和黄化突变体叶片为材料,分析了叶片和类囊体膜的不合色素组成、色素与蛋白相对含量;比较了类囊体膜光谱特性(室温吸收光谱、荧光光谱和圆二色谱);用温和电泳、SDS-PAGE分析了类囊体色素蛋白和多肽组成。结果显示:与野生型相比,突变体叶片的蛋白质含量不变,而Chaa和Chlb的含量均减少;突变体类囊体膜的Chla/Chlb比值较高,Chl/蛋白质比值较低,LHCⅡ色素蛋白复合物的单体和三聚体含量明显减少。突变体的天线系统相对较小、捕光效率较低。  相似文献   

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菠菜放氧的光系统Ⅱ(PSⅡ)核心复合物经0.8mol/L Tris(pH8.0)洗涤后,用温和的非离子去垢剂DM和高浓度的LiClO4增溶,再经DEAE-Toyopearl-650S离子交换柱层析分离,可得到PSⅡ天线组分中的叶绿素α/b结合蛋白(CP29)。SDS-PAGE显示一条30kD蛋白质带。根据Arnon法和Markwell法的结果表明,每个蛋白质分子结合有7~8个分子的叶绿素α和2~3  相似文献   

6.
光系统Ⅱ核心天线CP43的纯化及性质   总被引:7,自引:0,他引:7  
菠菜放氧的PSII核心复合物经0.8mol/LTris-HCl(pH8.0)洗涤后,用温和的非离子去垢剂DM和高浓度的LiClO4增溶,再经DEAE-Toyopearl-650S离子交换柱层析分离,可得到PSII核心天线43kD叶绿素a结合蛋白(CP43)。SDS-PAGE显示一条43kD蛋白质带。根据Arnon法和Markewll法的结果表明,每个蛋白质分子结合20~21个分子的叶绿素a。室温条  相似文献   

7.
褐藻光合作用色素_蛋白质复合物——研究进展和问题   总被引:3,自引:0,他引:3  
本文综述了近二十年来褐藻色素-蛋白质复合物的研究进展,包括色素-蛋白质复合物分离、褐藻的光系统Ⅰ、光系统Ⅱ及捕光色素-蛋白质复合物研究进展。并就藻色素-蛋白质复合物分离技术中存在的问题、褐藻的特点、褐藻与其它不铪 生物的色素-蛋白质复合物的同源性以及褐藻PSI复合物77K荧光发射的特点等进行了讨论。  相似文献   

8.
管藻目绿藻叶绿素蛋白复合物特性及比较研究   总被引:4,自引:1,他引:3  
陈敏  周百成 《Acta Botanica Sinica》2000,42(10):1019-1025
采用温和的PAGE法从管藻目刺松藻(Codium fragile (Sur.)Hariot)和假根羽藻(Bryopsis corticulans Setch.),丝藻目绿藻软丝藻(Ulothrix flacca (Dillw.)Thur.),及菠菜(Spinacia loeracea Mill.)中分别得到11、11、7和9种色素蛋白复合物,对复合物的多种特性,包括分子量、Chl a/b比值、叶绿  相似文献   

9.
为探讨肿瘤转移与细胞表面的糖结构的关系,对小鼠肝癌细胞的高、低淋巴道转移株Hca-F和Hca-P进行了蛋白质电泳及经蛋白质印迹术后的5种凝集素(ConA、WGA、UEA、SBA、PNA)结合糖蛋白谱的对比分析.结果表明:高、低转移两株细胞的SDS-PAGE谱基本相同;ConA特异结合糖蛋白共有5种(~72,80~90,~104,~150,~200kD);其中较明显的差异为~72kDConA特异结合糖蛋白,它在Hca-P细胞的表达明显高于Hca-F细胞.WGA特异结合糖蛋白1种(~150kD),在Hca-P细胞的表达略高于Hca-F细胞.此外,实验发现两种性质未明的蛋白质(~79,~130kD),后者在Hca-P细胞的含量明显高于Hca-P细胞.结果提示Hca-F和Hca-P细胞不同的转移表型可能与其糖蛋白的表达有一定的关联.  相似文献   

10.
点状产气单胞菌脯氨酰内肽酶基因克隆与序列测定   总被引:2,自引:0,他引:2  
点状产气单胞菌点状亚种(Aeromonas puncata subsp.punctata)具有脯氨酰内肽酶(prolyl endopeptidase PEP)活性。将其染色体DNA有Eco RⅠ部分酶切后回收8-16kb的DNA片段,与EcoRⅠ消化载体pUC18连接后转化E.coil DH5α,用该酶的专一性底物Benzyloxycarbonyl-Gly-β-naphthylamide从质粒库中  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

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For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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