玉米叶绿体atpB及atpE基因在大肠杆菌中的表达

本实验构建了在大肠杆菌中能表达玉米叶绿体ＣＦ１完整β亚基、缺失Ｎ端２３个氨基酸残基的β亚基以及完整ε亚基的表达质粒。ＳＤＳ－聚丙烯酰胺凝胶电泳及Ｗｅｓｔｅｒｎｂｌｏｔ实验表明,在分别含这些表达质粒的细菌中β、ε亚基蛋白的合成量在诱导３ｈ后即达到饱和,其含量各占细菌体总蛋白的１０％左右。这些表达产物在细菌体中形成不溶性的包含体。可通过对菌体蛋白的分级分高,将表达产物溶于５ｍｏｌ／Ｌ的尿素溶液中。     

Chloroplast Structure and Function Is Altered in the NCS2 Maize Mitochondrial Mutant

The nonchromosomal stripe 2 (NCS2) mutant of maize (Zea mays L.) has a DNA rearrangement in the mitochondrial genome that segregates with the abnormal growth phenotype. Yet, the NCS2 characteristic phenotype includes striped sectors of pale-green tissue on the leaves. This suggests a chloroplast abnormality. To characterize the chloroplasts present in the mutant sectors, we examined the chloroplast structure by electron microscopy, chloroplast function by radiolabeled carbon dioxide fixation and fluorescence induction kinetics, and thylakoid protein composition by polyacrylamide gel electrophoresis. The data from these analyses suggest abnormal or prematurely arrested chloroplast development. Deleterious effects of the NCS2 mutant mitochondria upon the cells of the leaf include structural and functional alterations in the both the bundle sheath and mesophyll chloroplasts.     

玉米AGO基因在籽粒发育过程中的表达分析

以玉米自交系‘昌7-2’授粉后4个时间点(授粉后7、10、14和20d)的籽粒总RNA为研究对象,采用实时荧光定量PCR技术,对玉米中5个Argonaute(AGO)蛋白家族基因(AGO1、AGO2、AGO4、AGO10和AGO18)在籽粒不同发育时期的表达谱进行了研究。结果表明:AGO1和AGO2在籽粒发育过程中呈现一致的表达趋势,在授粉后7d的籽粒中表达量最高,从授粉后7d到20d呈持续下降的趋势。AGO4、AGO10和AGO18具有一致的表达趋势,均呈现先下降后上升的趋势,在授粉后10d的籽粒中表达量最低。结合实验室前期获得的miRNA在玉米籽粒不同发育阶段的表达谱,发现不同AGO家族基因可协助其靶标miRNA参与玉米籽粒发育调控。     

玉米叶绿体表达载体的构建及AsRED基因原核表达

从玉米幼嫩叶片中提取玉米叶绿体基因DNA,通过PCR克隆出叶绿体同源重组片段trnA和trnI、叶绿体特异性启动子Prrn以及终止子psbA.构建玉米叶绿体表达载体pBAIRTARED,含有一个人工操纵子,其中,筛选标记基因aadA和红色荧光蛋白报告基因AsRED处于Prrn启动子和psbA终止子控制.将构建的载体转化大肠杆菌BL21（DE3）,观测到重组细胞呈现红色,表明构建的载体可以用于玉米叶绿体转化以及表达报告基因.     

Maize Mitochondrial Plasmid S-1 Sequences Share Homology with Chloroplast Gene psbA

The linear, 6397-base pair (bp), mitochondrial S-1 DNA molecule from maize contains a 420-bp segment that is homologous with the chloroplast gene (psbA) that codes for the quinone binding protein of photosystem II. This is the first report of a chloroplast sequence in a naturally occurring viral-like or plasmid DNA. The complete sequence of the S-1 chloroplast segment has been compared with homologous regions of six different chloroplast genes. The S-1 segment has diverged from the other genes both by length mutation and base substitution. Several of the length mutations are exact adjacent tandem duplications of 4 and 5 bp similar to "footprints" left after excision of transposable elements in maize nuclear DNA.     

植物线粒体基因的表达及控制的生命现象

线粒体控制的生命活动多种多样,决定植物的生长发育,本文对线粒体基因组特点,表达及其控制的生命现象等有内容作一总结。     

The Fate of Chloroplast Proteins during Photooxidation in Carotenoid-Deficient Maize Leaves

Maize seedlings, treated with the herbicide norflurazon to produce a deficiency in carotenoid pigments, were grown in low-fluence-rate light. Under these conditions, which induced chlorophyll biosynthesis while minimizing photooxidation, carotenoid-deficient seedlings showed identical patterns of chloroplast protein accumulation compared with normal seedlings. Carotenoid pigments thus play no direct role in regulating the accumulation of chloroplast proteins. When shifted to high-fluence-rate light, chlorophyll was rapidly photooxidized in carotenoid-deficient seedlings. Chloroplast proteins showed varying degrees of sensitivity to photooxidation. The P-700 apoprotein of photosystem I was rapidly degraded. Most stromal and thylakoid proteins either decreased progressively in photooxidative conditions or appeared to be unaffected. The relative quantity of the light-harvesting chlorophyll a/b-binding protein of photosystem II increased significantly in the first few hours of high-fluence-rate light. It then appeared to be only minimally affected 18 hours after complete photooxidation of chlorophyll.     

叶绿体遗传转化研究中的选择标记

叶绿体遗传转化研究需要有合适的选择标记作为辅助手段,多种选择标记已经在叶绿体转化中得到应用。本文综述了国内外叶绿体转化研究中主要使用的选择标记,并着重介绍了非抗生素选择标记－甜菜碱醛脱氢酶和选择标记的删除体系。     

Genome-Wide Analysis and Expression Patterns of the YUCCA Genes in Maize

<正>Auxin plays important roles in various aspects of plant growth and development(Zhao,2010).In Arabidopsis,a number of YUCCA(YUC)genes,which are involved in auxin biosynthesis,have been identified(Zhao et al.,2001;Woodward et al.,2005;Cheng et al.,2006,2007;Kim et al.,2007;Chen et al.,2014).YUC genes encode flavin monooxygenases(FMOs)that convert indole-3-pyruvate(IPA)to indole-3-acetic acid(IAA)(Zhao,2012).The Arabidopsis YUC family is comprised of 11 members(Zhao et al.,2001;     

Microsporogenesis and the Mechanism of Cytoplasmic Male Sterility in Maize

Examination of the structural changes occurring during microsporogenesisin cms-T, -C and -S Zea mays L. with different nuclear backgroundsrevealed considerable variations in the stages at which abortionof the sporocytes occurred within each cytoplasmic genotype.This variation was not associated with the nuclear background.Significantly, we found that the mitochondria in cms-T plantsdid not always follow the pattern of degeneration describedpreviously. We conclude that these observations are not consistentwith a proposed mechanism of cytoplasmic male sterility involvingthe direct, antagonistic action of an anther produced substanceon an altered mitochondrion or plastid, that is functionallynormal in the rest of the plant. The value of microscopic studiesin detecting variation in apparently uniform material is emphasised,though it is recognized that other methods will be requiredto elucidate the mechanism of male sterility. male sterility, mitochondria, cytoplasmic inhertance, microsporogenesis, Zeamays L., maize, corn     

Mitochondrial and Nuclear Genes of Mitochondrial Components in Cancer

Although the observation of aerobic glycolysis of tumor cells by Otto v. Warburg had demonstrated abnormalities of mitochondrial energy metabolism in cancer decades ago, there was no clear evidence for a functional role of mutant mitochondrial proteins in cancer development until the early years of the 21^st century. In the year 2000, a major breakthrough was achieved by the observation, that several genes coding for subunits of the respiratory chain (ETC) complex II, succinate dehydrogenase (SDH) are tumor suppressor genes in heritable paragangliomas, fulfilling Knudson’s classical two-hit hypothesis. A functional inactivation of both alleles by germline mutations and chromosomal losses in the tumor tissue was found in the patients. Later, SDH mutations were also identified in sporadic paragangliomas and pheochromocytomas. Genes of the mitochondrial ATP-synthase and of mitochondrial iron homeostasis have been implicated in cancer development at the level of cell culture and mouse experiments. In contrast to the well established role of some nuclear SDH genes, a functional impact of the mitochondrial genome itself (mtDNA) in cancer development remains unclear. Nevertheless, the extremely high frequency of mtDNA mutations in solid tumors raises the question, whether this small circular genome might be applicable to early cancer detection. This is a meaningful approach, especially in cancers, which tend to spread tumor cells early into bodily fluids or faeces, which can be screened by non-invasive methods.     

Increased Expression of Several Mitochondrial Genes in Human and Monkey B-Cell Non-Hodgkin Lymphomas

Mitochondrial genes overexpressed in human and monkey B-cell non-Hodgkin lymphomas (B-NHLs) were sought via subtraction hybridization, cloning, and differential screening of the resulting cDNA libraries. The cDNAs of mitochondrial genes constituted an appreciable proportion of all lymphoma-specific cDNAs. Lymphomogenesis was associated with upregulation of a set of mitochondrial genes, which varied with lymphoma type but always included NADHIV. A possible association between upregulation of certain mitochondrial genes and cell malignant transformation is discussed.