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1.
Nat Plants ; 10(4): 567-571, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38499777

RESUMO

Maize mutants of the centromeric histone H3 (CENP-A/CENH3) gene can form haploids that inherit only chromosomes of the pollinating parent but the cytoplasm from the female parent. We developed CENH3 haploid inducers carrying a dominant anthocyanin colour marker for efficient haploid identification and harbouring cytoplasmic male sterile cytoplasm, a type of cytoplasm that results in male sterility useful for efficient hybrid seed production. The resulting cytoplasmic male sterility cyto-swapping method provides a faster and cheaper way to convert commercial lines to cytoplasmic male sterile compared to conventional trait introgression.


Assuntos
Haploidia , Zea mays , Zea mays/genética , Zea mays/fisiologia , Infertilidade das Plantas/genética , Mutação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Citoplasma/genética , Citoplasma/metabolismo , Centrômero/genética , Histonas/metabolismo , Histonas/genética , Melhoramento Vegetal/métodos
2.
Plant Biotechnol J ; 4(1): 53-62, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17177785

RESUMO

Manganese peroxidase (MnP) has been implicated in lignin degradation and thus has potential applications in pulp and paper bleaching, enzymatic remediation and the textile industry. Transgenic plants are an emerging protein expression platform that offer many advantages over traditional systems, in particular their potential for large-scale industrial enzyme production. Several plant expression vectors were created to evaluate the accumulation of MnP from the wood-rot fungus Phanerochaete chrysosporium in maize seed. We showed that cell wall targeting yielded full-length MnP, whereas cytoplasmic localization resulted in multiple truncated peroxidase polypeptides as detected by immunoblot analysis. In addition, the use of a seed-preferred promoter dramatically increased the expression levels and reduced the negative effects on plant health. Multiple independent transgenic lines were backcrossed with elite inbred corn lines for several generations with the maintenance of high-level expression, indicating genetic stability of the transgene.


Assuntos
Peroxidases/genética , Peroxidases/metabolismo , Phanerochaete/enzimologia , Sementes/genética , Zea mays/genética , Biodegradação Ambiental , Biotecnologia , Parede Celular/enzimologia , Citoplasma/enzimologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Expressão Gênica , Genes Fúngicos , Lignina/metabolismo , Sementes/química , Sementes/metabolismo , Transformação Genética , Zea mays/química , Zea mays/metabolismo
3.
Plant Biotechnol J ; 3(1): 103-14, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17168903

RESUMO

The availability of foods low in sugar content yet high in flavour is critically important to millions of individuals conscious of carbohydrate intake for diabetic or dietetic purposes. Brazzein is a sweet protein occurring naturally in a tropical plant that is impractical to produce economically on a large scale, thus limiting its availability for food products. We report here the use of a maize expression system for the production of this naturally sweet protein. High expression of brazzein was obtained, with accumulation of up to 4% total soluble protein in maize seed. Purified corn brazzein possessed a sweetness intensity of up to 1200 times that of sucrose on a per weight basis. In addition, application tests demonstrated that brazzein-containing maize germ flour could be used directly in food applications, providing product sweetness. These results demonstrate that high-intensity sweet protein engineered into food products can give sweetener attributes useful in the food industry.

4.
Biotechnol Appl Biochem ; 38(Pt 2): 123-30, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12749769

RESUMO

Bovine trypsin (EC 3.4.21.4) is an enzyme that is widely used for commercial purposes to digest or process other proteins, including some therapeutic proteins. The biopharmaceutical industry is trying to eliminate animal-derived proteins from manufacturing processes due to the possible contamination of these products by human pathogens. Recombinant trypsin has been produced in a number of systems, including cell culture, bacteria and yeast. To date, these expression systems have not produced trypsin on a scale sufficient to fulfill the need of biopharmaceutical manufacturers where kilogram quantities are often required. The present paper describes commercial-level production of trypsin in transgenic maize (Zea mays) and its physical and functional characterization. This protease, the first enzyme to be produced on a large-scale using transgenic plant technology, is functionally equivalent to native bovine pancreatic trypsin. The availability of this reagent should allow for the replacement of animal-derived trypsin in the processing of pharmaceutical proteins.


Assuntos
Plantas Geneticamente Modificadas/enzimologia , Tripsina/genética , Zea mays/genética , Animais , Bovinos , Clonagem Molecular , Ativação Enzimática , Farinha , Glicosilação , Humanos , Cinética , Plantas Geneticamente Modificadas/química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Sementes/química , Sementes/enzimologia , Tripsina/biossíntese , Tripsina/metabolismo , Tripsinogênio/metabolismo , Zea mays/química , Zea mays/enzimologia
5.
Plant Biotechnol J ; 1(2): 129-40, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17147750

RESUMO

Expression of industrial enzymes in transgenic plants offers an alternative system to fungal fermentation for large-scale production. Very high levels of expression are required to make the enzymes cost-effective. We tested several parameters to determine the best method for achieving high levels of expression for a fungal laccase gene. Transgenic maize plants were generated using an Agrobacterium-mediated system. The molecular parameters that induced the highest expression were the maize embryo-preferred globulin 1 promoter and targeting of the protein to the cell wall. Two independent transgenic events that yielded multiple clonal plants were characterized in detail. Independent transgenic events 01 and 03 contained two or one copies of T-DNA, respectively. Plants derived from a single transgenic event varied in expression level, and the variation in expression levels was heritable. Within the seed, expression in these plants was primarily within the embryo, and was associated with seed browning and limited germination. High oil germplasm was used to increase germination, as well as to assist in increasing expression 20-fold in five generations through breeding and selection.

6.
J Control Release ; 85(1-3): 169-80, 2002 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-12480322

RESUMO

The use of recombinant gene technologies by the vaccine industry has revolutionized the way antigens are generated, and has provided safer, more effective means of protecting animals and humans against bacterial and viral pathogens. Viral and bacterial antigens for recombinant subunit vaccines have been produced in a variety of organisms. Transgenic plants are now recognized as legitimate sources for these proteins, especially in the developing area of oral vaccines, because antigens have been shown to be correctly processed in plants into forms that elicit immune responses when fed to animals or humans. Antigens expressed in maize (Zea mays) are particularly attractive since they can be deposited in the natural storage vessel, the corn seed, and can be conveniently delivered to any organism that consumes grain. We have previously demonstrated high level expression of the B-subunit of Escherichia coli heat-labile enterotoxin and the spike protein of swine transmissible gastroenteritis in corn, and have demonstrated that these antigens delivered in the seed elicit protective immune responses. Here we provide additional data to support the potency, efficacy, and stability of recombinant subunit vaccines delivered in maize seed.


Assuntos
Sistemas de Liberação de Medicamentos/veterinária , Proteínas de Escherichia coli , Sementes , Vacinação/veterinária , Vacinas Sintéticas/administração & dosagem , Zea mays , Administração Oral , Animais , Toxinas Bacterianas/administração & dosagem , Toxinas Bacterianas/imunologia , Química Farmacêutica , Enterotoxinas/administração & dosagem , Enterotoxinas/imunologia , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Gastroenterite Suína Transmissível/prevenção & controle , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/administração & dosagem , Extratos Vegetais/imunologia , Plantas Geneticamente Modificadas/imunologia , Sementes/imunologia , Sementes/microbiologia , Sementes/virologia , Suínos , Vírus da Gastroenterite Transmissível/imunologia , Vacinas Sintéticas/imunologia , Proteínas Virais/administração & dosagem , Proteínas Virais/imunologia , Zea mays/imunologia
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