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1دورية أكاديمية
المؤلفون: Lining Tian, Brian Miki, Dan Brown, Keqiang Wu
المساهمون: The Pennsylvania State University CiteSeerX Archives
الوصف: Eukaryotic genes are regulated by a hierarchy of intricate controls that include modifications to chromatin structure. Within the primary chromatin fiber, DNA is packaged into nucleosomes by core histones. Posttranscriptional modification of nucleosomal histones, particularly through acetylation and deacetylation, is an important mechanism in the regulation of eukaryotic gene expression. Acetylation of the histones by acetyltransferases leads to a relaxed association, and thus, enhances accessibility
وصف الملف: application/pdf
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المؤلفون: Yuzuki Manabe, Hélène Labbé, Brian Miki, Jaimie Schnell, Nik Kovinich
المصدر: Transgenic Research. 21:1255-1264
مصطلحات موضوعية: Transgene, Mutant, Arabidopsis, Mutagenesis (molecular biology technique), Genes, Plant, Niacin, Transcriptome, chemistry.chemical_compound, Gene Expression Regulation, Plant, Genetics, Gene, Oligonucleotide Array Sequence Analysis, Acetolactate synthase, biology, Arabidopsis Proteins, Gene Expression Profiling, Genetic Complementation Test, Imidazoles, Imazapyr, Plants, Genetically Modified, biology.organism_classification, chemistry, Mutagenesis, Mutation, biology.protein, Animal Science and Zoology, Agronomy and Crop Science, Herbicide Resistance, Biotechnology
الوصف: The Arabidopsis CSR1 gene codes for the enzyme acetohydroxyacid synthase (AHAS, EC 2.2.1.6), also known as acetolactate synthase, which catalyzes the first step in branched-chain amino acid biosynthesis. It is inhibited by several classes of herbicides, including the imidazolinone herbicides, such as imazapyr; however, a substitution mutation in csr1-2 (Ser-653-Asn) confers selective resistance to the imidazolinones. The transcriptome of csr1-2 seedlings grown in the presence of imazapyr has been shown in a previous study (Manabe in Plant Cell Physiol 48:1340-1358, 2007) to be identical to that of wild-type seedlings indicating that AHAS is the sole target of imazapyr and that the mutation is not associated with pleiotropic effects detectable by transcriptome analysis. In this study, a lethal null mutant, csr1-7, created by a T-DNA insertion into the CSR1 gene was complemented with a randomly-inserted 35S/CSR1-2/NOS transgene in a subsequent genetic transformation event. A comparison of the csr1-2 substitution mutant with the transgenic lines revealed that all were resistant to imazapyr; however, the transgenic lines yielded significantly higher levels of resistance and greater biomass accumulation in the presence of imazapyr. Microarray analysis revealed few differences in their transcriptomes. The most notable was a sevenfold to tenfold elevation in the CSR1-2 transcript level. The data indicate that transgenesis did not create significant unintended pleiotropic effects on gene expression and that the mutant and transgenic lines were highly similar, except for the level of herbicide resistance.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6dc1a25b6961962f15bc6a80de300defTest
https://doi.org/10.1007/s11248-012-9597-zTest -
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المؤلفون: Ammar Saleem, Nik Kovinich, John T. Arnason, Brian Miki
المصدر: Journal of Agricultural and Food Chemistry. 60:574-584
مصطلحات موضوعية: Coat, Flavonoid, Mutant, Cyanidin, Color, Biology, Genes, Plant, Genetically modified soybean, Catechin, Anthocyanidin reductase, chemistry.chemical_compound, Gene Expression Regulation, Plant, NADH, NADPH Oxidoreductases, Proanthocyanidins, RNA, Messenger, Phylogeny, chemistry.chemical_classification, food and beverages, General Chemistry, Recombinant Proteins, chemistry, Biochemistry, Proanthocyanidin, Multigene Family, Anthocyanin, Mutation, Seeds, Soybeans, General Agricultural and Biological Sciences
الوصف: Anthocyanidin reductase (ANR; EC 1.3.1.77) catalyzes a key step in the biosynthesis of proanthocyanidins (PAs; also known as condensed tannins), flavonoid metabolites responsible for the brown pigmentation of seeds. Here, two ANR genes (ANR1 and ANR2) from the seed coat of brown soybean (Glycine max (L.) Merr.) have been isolated and their enzymatic function confirmed for the reduction of cyanidin to (-)-epicatechin in vitro. Biochemical and genetic comparisons of soybean lines differing in seed coat color revealed three red-brown lines to exhibit major reductions in the amounts of soluble PAs in the seed coat compared to brown soybean lines. Two spontaneous mutants with red-brown grain color had reduced ANR1 gene expression in the seed coat, and an EMS-mutagenized red-brown mutant had nonsynonymous substitutions that resulted in slightly reduced ANR1 activity in vitro. These results suggest that defects in the ANR1 gene can be associated with red-brown soybean grain color. These results suggest that suppressing ANR1 gene expression or activity may be a rational approach toward engineering seed coat color to enable the visual identification of genetically modified soybean grains.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f2c90a0bcfcd8fad54e8ad6b3fbd1d0fTest
https://doi.org/10.1021/jf2033939Test -
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المؤلفون: John T. Arnason, Brian Miki, Nik Kovinich, Ammar Saleem
المصدر: Phytochemistry. 71:1253-1263
مصطلحات موضوعية: Flavonoid, Cyanidin, Plant Science, Horticulture, Biochemistry, Anthocyanins, chemistry.chemical_compound, Flavonols, Petunidin, Molecular Biology, Anthocyanidin, Flavonoids, chemistry.chemical_classification, Molecular Structure, biology, fungi, food and beverages, General Medicine, carbohydrates (lipids), chemistry, Glucosyltransferases, Anthocyanin, Seeds, biology.protein, Glucosyltransferase, Soybeans, Delphinidin
الوصف: The seed coats of black soybean ( Glycine max (L.) Merr.) accumulate red (cyanidin-), blue (delphinidin-), purple (petunidin-), and orange (pelargonidin-based) anthocyanins almost exclusively as 3- O -glucosides; however, the responsible enzyme has not been identified. In this study, the full-length cDNA which encodes the enzyme that catalyzes the final step in anthocyanin biosynthesis, namely UDP-glucose:flavonoid 3- O -glucosyltransferase ( UGT78K1 ), was isolated from the seed coat tissue of black soybean using rapid amplification of cDNA ends (RACE). Of the 28 flavonoid substrates tested, the purified recombinant protein glucosylated only anthocyanidins and flavonols, and demonstrated strict 3-OH regiospecificity. Galactose could also be transferred with relatively low activity to the 3-position of cyanidin or delphinidin in vitro . These findings are consistent with previous reports of mainly 3- O -glucosylated and minor amounts of 3- O -galactosylated anthocyanins in the seed coat of black soybean. The recombinant enzyme exhibited pronounced substrate inhibition by cyanidin at 100 μM acceptor concentration. Transfer of UGT78K1 into the Arabidopsis T-DNA mutant ( ugt78d2 ) deficient in anthocyanidin and flavonol 3- O -glucosyltransferase activity, restored the accumulation of anthocyanins and flavonols, suggesting the in vivo function of the enzyme as a flavonoid 3- O -glucosyltransferase. Genomic and phylogenetic analyses suggest the existence of three additional soybean sequences with high similarity to UGT78K1 . RT-PCR confirmed the co-expression of one of these genes (Glyma08g07130) with UGT78K1 in the seed coat of black soybean, suggesting possible functional redundancies in anthocyanin biosynthesis in this tissue.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::72e8990264476f4bdaeaf16dce70fe84Test
https://doi.org/10.1016/j.phytochem.2010.05.009Test -
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المؤلفون: Ashraf Abdeen, Brian Miki
المصدر: Plant Biotechnology Journal. 7:266-282
مصطلحات موضوعية: Arabidopsis, Plant Science, Genetically modified crops, Transcriptome, chemistry.chemical_compound, Gene Expression Regulation, Plant, Arabidopsis thaliana, Oligonucleotide Array Sequence Analysis, Regulation of gene expression, Genetics, biology, Herbicides, Aminobutyrates, Gene Expression Profiling, fungi, food and beverages, Bialaphos, Plants, Genetically Modified, biology.organism_classification, Gene expression profiling, Glufosinate, chemistry, RNA, Plant, Agronomy and Crop Science, Biotechnology
الوصف: The Arabidopsis transcriptome was studied using the Affymetrix Arabidopsis ATH1 GeneChip in wild-type plants and glufosinate-tolerant transgenic plants expressing the bialaphos resistance (bar) gene. Pleiotropic effects were specifically generated in the transcriptomes of transgenic plants by both the bar gene and glufosinate treatments. In the absence of glufosinate, four genes were differentially expressed in the transgenic lines and another 80 genes were differentially expressed in the presence of glufosinate, 29 of which were specific to transgenic plants. In contrast, the number of differentially expressed genes specific to wild-type plants was 194 during the early response at 6 h of glufosinate treatment, and increased to 3711 during the late response at 48 h. Although the wild-type plants undergo extensive transcriptional reprofiling in response to herbicide-induced stress and, finally, plant death, the transgenic plants appear to activate other detoxification processes to offset the toxic effects of the residual herbicide or its derivatives. This study provides the first description of the pleiotropic effects of the bar gene and glufosinate on the plant transcriptome.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::06003ba86e4327880c79c19f44bfbc9cTest
https://doi.org/10.1111/j.1467-7652.2008.00398.xTest -
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المؤلفون: Ashraf Abdeen, Yuzuki Manabe, Brian Miki, Phil Macdonald
المصدر: Plant Biotechnology Journal. 7:211-218
مصطلحات موضوعية: Genetic Markers, Regulation of gene expression, Genetics, Reporter gene, Gene Expression Profiling, Mutagenesis (molecular biology technique), Plant Science, Biology, Plants, Genetically Modified, Gene expression profiling, Mutagenesis, Insertional, Gene Expression Regulation, Plant, Pleiotropy, Genetic marker, Transgenes, Agronomy and Crop Science, Gene, Genome, Plant, Selectable marker, Biotechnology
الوصف: The intended effect of a selectable marker gene is to confer a novel trait that allows for the selection and recovery of transgenic plants. Unintended effects may also occur as a result of interactions between the selectable marker gene or its regulatory elements and genetic elements at the site of insertion. These are called position effects. Other unintended effects may occur if the selectable marker gene has a range of pleiotropic effects related to the functional and regulatory domains within the coding region or the regulatory elements used to drive expression. Both pleiotropic and position effects may generate unpredictable events depending on the process used for transgenesis and the state of knowledge associated with the selectable marker gene. Although some selectable marker genes, such as the neomycin phosphotransferase type II gene (nptII), have no pleiotropic effects on the transcriptomes of transgenic plants, others, such as the bialaphos resistance gene (bar), have pleiotropic effects. These must be clearly understood and accounted for when evaluating the expression patterns conferred by other co-transforming transgenes under study. The number and kinds of selectable marker genes are large. A detailed understanding of their unintended effects is needed to develop transgenic strategies that will minimize or eliminate unintended and unpredictable changes to plants with newly inserted genes.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c182ded7f66b274a2d08f816e478dc79Test
https://doi.org/10.1111/j.1467-7652.2009.00400.xTest -
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المؤلفون: Adam Colville, Yuzuki Manabe, Brian Miki, Nicholas A. Tinker
المصدر: Plant and Cell Physiology. 48:1340-1358
مصطلحات موضوعية: Alternative oxidase, Physiology, Mutant, Arabidopsis, Plant Science, Biology, Genes, Plant, Niacin, Transcriptome, chemistry.chemical_compound, Gene Expression Regulation, Plant, Arabidopsis thaliana, Gene, Oligonucleotide Array Sequence Analysis, Genetics, Oxidase test, Arabidopsis Proteins, Herbicides, Gene Expression Profiling, Imidazoles, Cytochrome P450, Cell Biology, General Medicine, Imazapyr, biology.organism_classification, Acetolactate Synthase, chemistry, Mutation, biology.protein, Herbicide Resistance
الوصف: The imidazolinone-tolerant mutant of Arabidopsis thaliana, csr1-2(D), carries a mutation equivalent to that found in commercially available Clearfield crops. Despite their widespread usage, the mechanism by which Clearfield crops gain imidazolinone herbicide tolerance has not yet been fully characterized. Transcription profiling of imazapyr (an imidazolinone herbicide)-treated wild-type and csr1-2(D) mutant plants using Affymetrix ATH1 GeneChip microarrays was performed to elucidate further the biochemical and genetic mechanisms of imidazolinone resistance. In wild-type shoots, the genes which responded earliest to imazapyr treatment were detoxification-related genes which have also been shown to be induced by other abiotic stresses. Early-response genes included steroid sulfotransferase (ST) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO), as well as members of the glycosyltransferase, glutathione transferase (GST), cytochrome P450, ATP-binding cassette (ABC) transporter, multidrug and toxin extrusion (MATE) and alternative oxidase (AOX) protein families. Later stages of the imazapyr response involved regulation of genes participating in biosynthesis of amino acids, secondary metabolites and tRNA. In contrast to the dynamic changes in the transcriptome profile observed in imazapyr-treated wild-type plants, the transcriptome of csr1-2(D) did not exhibit significant changes following imazapyr treatment, compared with mock-treated csr1-2(D). Further, no substantial difference was observed between wild-type and csr1-2(D) transcriptomes in the absence of imazapyr treatment. These results indicate that CSR1 is the sole target of imidazolinone and that the csr1-2(D) mutation has little or no detrimental effect on whole-plant fitness.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d43a11f064b593296e66160a43f9e568Test
https://doi.org/10.1093/pcp/pcm105Test -
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المؤلفون: Catherine Coutu, Brian Miki, Dwayne D. Hegedus, Jim Brandle, John Simmonds, Daniel C. W. Brown, Kirk Brown
المصدر: Transgenic Research. 16:771-781
مصطلحات موضوعية: FLP-FRT recombination, Genetic Vectors, Molecular Sequence Data, Arabidopsis, Biology, Origin of replication, Zea mays, Transformation, Genetic, Plasmid, Genetics, Multiple cloning site, Selectable marker, Reporter gene, ColE1, Brassica napus, fungi, Peas, Plants, Genetically Modified, Transformation (genetics), Agrobacterium tumefaciens, Animal Science and Zoology, Soybeans, Agronomy and Crop Science, Plasmids, Biotechnology
الوصف: We present a series of 14 binary vectors suitable for Agrobacterium-mediated transformation of dicotyledonous plants and adaptable for biolistic transformation of monocotyledonous plants. The vector size has been minimized by eliminating all non-essential elements from the vector backbone and T-DNA regions while maintaining the ability to replicate independently. The smallest of the vector series is 6.3 kb and possesses an extensive multiple cloning site with 21 unique restriction endonuclease sites that are compatible with common cloning, protein expression, yeast two-hybrid and other binary vectors. The T-DNA region was engineered using a synthetic designer oligonucleotide resulting in an entirely modular system whereby any vector element can be independently exchanged. The high copy number ColE1 origin of replication has been included to enhance plasmid yield in Escherichia coli. FRT recombination sites flank the selectable marker cassette regions and allow for in planta excision by FLP recombinase. The pORE series consists of three basic types; an ‘open’ set for general plant transformation, a ‘reporter’ set for promoter analysis and an ‘expression’ set for constitutive expression of transgenes. The sets comprise various combinations of promoters (P HPL, P ENTCUP2 and P TAPADH), selectable markers (nptII and pat) and reporter genes (gusA and smgfp).
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ad17cd1f54a4f5ca6a10ff094d056f70Test
https://doi.org/10.1007/s11248-007-9066-2Test -
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المؤلفون: Lining Tian, Marysia Latoszek-Green, Keqiang Wu, Susan Sibbald, Ming Hu, Daniel C. W. Brown, Brian Miki, Carol Hannam
المصدر: Journal of Plant Physiology. 162:1355-1366
مصطلحات موضوعية: Genetics, Base Sequence, DNA, Plant, Physiology, Transgene, Molecular Sequence Data, Intron, Promoter, Sequence Analysis, DNA, Plant Science, Biology, Plants, Genetically Modified, Introns, Transformation, Genetic, Gene Expression Regulation, Plant, eIF4A, Eukaryotic Initiation Factor-4A, Tobacco, Gene expression, Gene family, Cloning, Molecular, Promoter Regions, Genetic, Enhancer, Agronomy and Crop Science, Gene
الوصف: Summary The eIF4A gene family codes for proteins which unwind secondary structures of mRNA during translational initiation. The tobacco eIF4A-10 promoter is one of a few examples of constitutive promoters found in plants. Research was conducted to identify the proximal promoter elements and to evaluate the potential application of the promoter for regulating transgene expression in a range of crop plants. A large intron (892 bp) in the leader sequence was found to be dispensable for constitutive promoter activity and did not contribute to the overall performance of the promoter. Deletion analysis showed that the upstream region between −151 bp and −73 bp relative to the transcriptional start site was essential for the high level of expression and the constitutive activity. The data indicated that the elements in this region may coordinate and compensate each other for the high levels of promoter expression. The downstream leader sequence also contained a strong quantitative enhancer element that was essential for the full activity of the eIF4A-10 promoter. The eIF-4A10 promoter was found to be active in a wide range of plant species and tissues indicating that it will be useful for the constitutive expression of transgenes in plants.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::534bbdc88360599573f3721f4ad89815Test
https://doi.org/10.1016/j.jplph.2005.03.011Test
