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... Red clover contains high levels of polyphenol oxidase (PPO) activity and o-diphenol substrates. This results in a characteristic post-harvest browning reaction associated with decreased protein degradation during ensiling. To define PPO's role in inhibition of post-harvest proteolysis, we are taking both biochemical and molecular approaches. We have cloned three unique PPO cDNAs from red clover le ...
... Water stress associated with drought-like conditions is a major factor limiting plant growth and impacts productivity of natural plant communities and agricultural crops. Molecular responses of plants to water stress have been studied most extensively in model species and crops, few of which have evolved natural drought tolerance. In the current study, we examined physiological and transcriptomic ...
... SynopsisA method for establishing autotetraploid synthetic varieties of maize by genetic means is outlined. The ultimate use of these synthetic varieties as a source of breeding material is proposed. If genetic inbalance is largely responsible for low seed set in maize tetraploids, fertile inbreds or fertile hybrid combinations can be expected to be isolated from synthetic varieties that are genet ...
... Phylloclades are traditionally defined as flattened, determinate, leaf-like stems primarily on the basis of their axillary position. However, because the literature is replete with controversy over the morphological interpretation of these organs, a study of phylloclade development in comparison with leaf and stem development was undertaken in four closely related species of the Asparagaceae: Rusc ...
... To investigate the regulation of gene expression during male gametophyte development, we analyzed the promoter activity of two different genes (LAT52 and LAT59) from tomato, isolated on the basis of their anther-specific expression. In transgenic tomato, tobacco and Arabidopsis plants containing the LAT52 promoter region fused to the beta-glucuronidase (GUS) gene, GUS activity was restricted to po ...
... Promoter sequences from the Aspergillus niger glucoamylase-encoding gene (glaA) were linked to the bacterial hygromycin (Hy) phosphotransferase-encoding gene (hph) and this chimeric marker was used to select Hy-resistant (hy(R)) Ustilago maydis transformants. This is an example of an Ascomycete promoter functioning in a Basidiomycete. Hy(R) transformants varied with respect to copy number of integ ...
Lisa N. Hall; Gregory A. Tucker; Christopher J.S. Smith; Colin F. Watson; Graham B. Seymour; Yvonne Bundick; Jeremy M. Boniwell; Jonathan D. Fletcher; John A. Ray; Wolfgang Schuch; Colin R. Bird; Don Grierson
... Tomato plants (Lycopersicon esculentum Mill. cv. Ailsa Craig) were transformed with chimaeric pectin esterase (PE; EC 3.1.1.11) antisense RNA genes, based on a cDNA isolated from a tomato fruit library. PE enzyme activity in ripe fruit of these plants was reduced by up to 93%, as a result of inhibition of PE mRNA accumulation from an endogenous gene, or genes. No major differences in fruit develop ...
... The rolA gene not only provokes the abnormal traits of wrinkled leaves, shortened internodes, and deficient root growth in tobacco, but also induction of roots in leaf disks in hormone‐free medium. The rolA mRNA is most abundant in the stem of transgenic tobacco, accumulating at fivefold and 50‐fold lower levels in the leaf and the root, respectively. Promoter deletion mutants were constructed and ...
in vivo studies; flowering; cell culture; scotophase; genes; Chlamydomonas reinhardtii; Angiospermae; RNA; gene expression regulation
Abstract:
... Changes in the relative sizes of pools of transcripts of organelle genes during plastid development are common in flowering plants, but technical difficulties have prevented direct determinations of the effects of changes in rates of transcription and degradation on such fluctuations. It has been possible to follow both rates in Chlamydomonas reinhardtii. In synchronous or asynchronous cultures of ...
... These experiments were carried out to investigate whether accumulation of carbohydrate leads to decreased expression of genes involved in photosynthesis. Addition of glucose to autotrophic cell suspension cultures of Chenopodium led to a large and reversible decrease of the steady state transcript levels of rbcS, cab and atp‐& within 5 h, but did not decrease 18S rRNA or transcript for two glycoly ...
... The methionine content in maize kernels is largely determined by the level of a methionine-rich 10 kDa protein, encoded by the gene Zps10/(22). In the maize inbred BSSS53 this gene is over-expressed compared with its normal expression in inbred lines like W64A and W22. This is in part due to the trans-acting factor Zpr10/(22). However, compared with the normal level of expression, this gene is und ...
... This paper reports on the isolation of a novel class of plant serine/threonine protein kinase genes, MsK‐1, MsK‐2 and MsK‐3. They belong to the superfamily of cdc2‐like genes, but show highest identity to the Drosophila shaggy and rat GSK‐3 proteins (65–70%). All of these kinases share a highly conserved catalytic protein kinase domain. Different amino‐terminal extensions distinguish the different ...
... Phenylalanine ammonia‐lyase (PAL) catalyses the first committed step in the biosynthesis of phenyl‐propanoids, which perform a variety of functions in plant development and in their interactions with the environment. French bean contains a small family of genes encoding PAL and two of these genes, PAL2 and PAL3, have been shown to be differentially expressed at the mRNA level in bean tissues. The ...
... The effects of transiently elevated cytokinin levels on gene expression following stress were examined in transgenic Nicotiana plumbaginifolia plants. Plants were transformed with a bacterial gene encoding isopentenyl transferase (ipt) cloned behind the heat shock (HS) protein 70 promoter from Drosophila melanogaster. Following a l‐h, 45°C HS of whole plants, the ipt transcript levels in leaves in ...
... In this paper we describe the expression patterns of a family of homeobox genes in maize and their relationship to organogenic domains in the vegetative shoot apical meristem. These genes are related by sequence to KNOTTED1, a gene characterized by dominant neomorphic mutations which perturb specific aspects of maize leaf development. Four members of this gene family are expressed in shoot meriste ...
Aequorea victoria; green fluorescent protein; biomarkers; gene expression regulation
Abstract:
... A complementary DNA for the Aequorea victoria green fluorescent protein (GFP) produces a fluorescent product when expressed in prokaryotic (Escherichia coli) or eukaryotic (Caenorhabditis elegans) cells. Because exogenous substrates and cofactors are not required for this fluorescence, GFP expression can be used to monitor gene expression and protein localization in living organisms. ...
... Cells of Saccharomyces cerevisiae grown in media with an initial pH of 2.5-6.0, acidified with a strong acid (HCl), exhibited the highest plasma membrane H+-ATPase-specific activity at an initial pH of 6.0. At a lower pH (above pH 2.5) ATPase activity (62-83% of the maximum level) still allowed optimal growth. At pH 2.5. ATPase activity was about 30% of the maximum value and growth was impaired. Q ...
... The response of a rapidly growing, transformable maize suspension cell culture line (Zea mays L. A188 x BMS) to changes in media N and NO3- treatment was examined. Growth, N content, enzyme activities and transcript levels were measured in cells transferred to N-rich media (N6) or to media lacking N (N-free). Transferring cells to N-free media had little impact on cell growth (fresh and dry weight ...
... The glucose transporter of Trypanosoma brucei procyclic forms was characterized and compared with its bloodstream form counterpart. Measuring the glucose consumption enzymatically, we determined a saturable uptake process of relatively high affinity (Km = 80 micromolar Vmax = 4 nmol mine-1 10(-8) cells), which showed substrate inhibition at glucose concentrations above 1.5 mM (Ki = 21 mM). Control ...
... The effect of pectic polysaccharide, bupleuran 2IIb, on clearance of immune complex from circulation in vivo was examined in mice. The immune complex clearance was enhanced by intraperitoneal treatment of bupleuran 2IIb in a dose dependent fashion, whereas clearance of colloidal carbon was reduced by bupleuran 2IIb‐treatment. The body and organ weights were not significantly altered in bupleuran 2 ...
Trichoderma virens; antibiotics; biological control; biological control agents; biosynthesis; damping off; fungi; gene expression regulation; nutritional status
Abstract:
... Gliocladium virens is a filamentous fungus formulated for the biological control of damping-off diseases of plants. Part of its antagonistic activity is due to its production of an epidithiodiketopiperazine antibiotic, gliotoxin. A relatively short period of biocontrol activity limits the use of this biocontrol agent in certain applications. This report examines the apparent transient accumulation ...
... Pupal forewing epidermis of the Coleoptera, Tenebrio molitor, was used to develop an in vitro system to study the hormonal control of metamorphosis at the cellular and molecular levels. Exposure to 1 micromolar 20-hydroxyecdysone for 48 h caused the formation of a typical adult cuticle. Under these conditions the expression of ACP-20, an adult-specific cuticular gene, was fivefold higher than in a ...
... HIV infection causes dysregulation of cytokine gene expression in CD4⁺ T cells of the infected host. Azidothymidine (AZT) inhibits HIV repli-cation by blocking reverse transcription. Using a one-stop cell-to-cell HIV infection model, we have investigated the expression of several key cytokines in HIV infected T cells in the absence or presence of AZT treatment. Acute HIV infection of T cells resul ...
... Transgenic plants of Gladiolus were created following particle gun bombardment with either the bean yellow mosaic virus coat protein or gusA gene each under control of the CaMV 35S promoter. Monoclonal antibodies were used in ELISA assays to detect expression of the bean yellow mosaic virus coat protein in leaves of the transgenic plants. The bean yellow mosaic virus coat protein was expressed in ...
... A genomic clone (Ext 1.4) encoding an extensin was isolated from a Nicotiana tabacum genomic library. The encoded polypeptide showed features characteristic of extensins such as Ser-(Pro)4 repeats and a high content in Tyr and Lys residues. The presence of one Tyr-Leu-Tyr-Lys motif suggests the possibility for one intramolecular isodityrosine cross-link whereas numerous Val-Tyr-Lys motifs may part ...
... In normal female mammals, one of the two X Chromosome (Chr) homologs per cell is silenced coordinately during early embryogenesis. The genes located on the inactivated X homolog are predicted to be influenced by the same underlying repression mechanism. To test the uniformity of cis-acting gene repression, 32 genetically identical F₁ female mice were analyzed for differential expression of homolog ...
... The relative levels of selected cytokine, interleukin-2 receptor, class II DR and DQ RNAs, and maedi visna virus (MVV) RNA were measured by reverse-transcriptase polymerase chain reaction (RT-PCR) in the lungs of sheep with natural maedi visna virus infection (n = 8) and a group of age/sex/breed-matched MVV seronegative sheep (n = 4). These animals were divided into two groups, irrespective of ser ...
... Numerous plant processes ranging from signal transduction to metabolism appear to be mediated, in part, by type 2A protein serine/threonine phosphatases (PP2A). In an effort to identify factors that control the activity of this enzyme in plants, we have isolated and characterized DNA sequences encoding the B' regulatory subunit of PP2A from Arabidopsis thaliana. Specifically, we used PCR to amplif ...
... Antisense oligonucleotide represents an interesting tool for selective inhibition of gene expression. However, their low efficiency of introduction within intact cells remains to be overcome. Antisense-TGFβ (25 mer) and antisense-TNFα (18 mer) were used to study the cellular transport and biological function of antisense oligonucleotide in vitro. Since TGF and TNF play on important role in regulat ...
... A red-shifted, mutated form of the jelly-fish green fluorescent protein (GFP) under control of a TEF promoter was expressed at high levels in the filamentous fungus Aureobasidium pullulans. In the three transformants studied, all morphotypes of the fungus, including pigmented chlamydospores, expressed GFP and fluoresced brightly. Confocal microscopy showed that the intra-cellular distribution of G ...
messenger RNA; Human alphaherpesvirus 1; Felid alphaherpesvirus 1; genes; gene expression regulation; promoter regions
Abstract:
... Feline herpesvirus type 1 (FHV-1) produces a single 5.4 kb immediate-early (IE) transcript encoding FHV-1 ICP4 which acts as a trans-acting factor [Kawaguchi et al. (1994) Virology 204: 430–435]. Our earlier study has shown that the FHV-1 IE transcript is spliced in the leader region and the FHV-1 IE gene product (ICP4) down-regulates its own promoter through the region which includes its transcri ...
... The mammalian high mobility group proteins HMGI/Y and HMG1/2 are thought to play an architectural role in assembly of nucleoprotein structures. Counterparts to these proteins have recently been found in the cells of the Dipteran insectChironomus. In this report we investigate the distribution of three abundant HMG proteins in interphase giant chromosomes of the midge,Chironomus. By means of the in ...
... Glyoxalase II is part of the glutathione-dependent glyoxalase detoxification system. In addition to its role in the detoxification of cytotoxic 2-oxo-aldehydes, specifically methylglyoxal, it has been suggested that the glyoxalase system may also play a role in controlling cell differentiation and proliferation. During the analysis of a T-DNA-tagged mutant of Arabidopsis we identified the gene for ...
... A visibly distinct muscular hypertrophy (mh), commonly known as double muscling, occurs with high frequency in the Belgian Blue and Piedmontese cattle breeds. The autosomal recessive mh locus causing double-muscling condition in these cattle maps to bovine chromosome 2 within the same interval as myostatin, a member of the TGF-β superfamily of genes. Because targeted disruption of myostatin in mic ...
... Oestradiol acts both as a mitogen and as an inducer of differentiation of target cells. The cellular responses to oestradiol are generally mediated through the regulation of gene expression, although nongenomic modes of action are also documented. The present observations show that the regulation of keratin gene expression in rat vaginal epithelial cells is under the influence of oestradiol. It is ...