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Your search keyword '"Mortimer, Cara"' showing total 2 results
Start Over Author "Mortimer, Cara" Publisher american society of plant biologists
2 results on '"Mortimer, Cara"'

1. In plant activation: An inducible, hyperexpression platform for recombinant protein production in plants

Author

Dugdale, Benjamin, Mortimer, Cara, Kato, Maiko, James, Tess, Harding, Rob, Dale, James, Dugdale, Benjamin, Mortimer, Cara, Kato, Maiko, James, Tess, Harding, Rob, and Dale, James

Abstract

In this study, we describe a novel protein production platform that provides both activation and amplification of transgene expression in planta. The In Plant Activation (INPACT) system is based on the replication machinery of tobacco yellow dwarf mastrevirus (TYDV) and is essentially transient gene expression from a stably transformed plant, thus combining the advantages of both means of expression. The INPACT cassette is uniquely arranged such that the gene of interest is split and only reconstituted in the presence of the TYDV-encoded Rep/RepA proteins. Rep/RepA expression is placed under the control of the AlcA:AlcR gene switch, which is responsive to trace levels of ethanol. Transgenic tobacco (Nicotiana tabacum cv Samsun) plants containing an INPACT cassette encoding the b-glucuronidase (GUS) reporter had negligible background expression but accumulated very high GUS levels (up to 10% total soluble protein) throughout the plant, within 3 d of a 1% ethanol application. The GUS reporter was replaced with a gene encoding a lethal ribonuclease, barnase, demonstrating that the INPACT system provides exquisite control of transgene expression and can be adapted to potentially toxic or inhibitory compounds. The INPACT gene expression platform is scalable, not host-limited, and has been used to express both a therapeutic and an industrial protein.

Published
2013

2. The Formation and Sequestration of Nonendogenous Ketocarotenoids in Transgenic Nicotiana glauca .

Author

Mortimer CL, Misawa N, Perez-Fons L, Robertson FP, Harada H, Bramley PM, and Fraser PD

Subjects
Bacterial Proteins genetics, Bacterial Proteins metabolism, Biosynthetic Pathways genetics, Carotenoids chemistry, Caulobacteraceae enzymology, Caulobacteraceae genetics, Flowers chemistry, Flowers genetics, Flowers metabolism, Gene Expression, Microscopy, Electron, Transmission, Mixed Function Oxygenases genetics, Mixed Function Oxygenases metabolism, Molecular Structure, Oxygenases genetics, Oxygenases metabolism, Plant Leaves chemistry, Plant Leaves genetics, Plant Leaves metabolism, Plants, Genetically Modified genetics, Plastids genetics, Plastids metabolism, Plastids ultrastructure, Reverse Transcriptase Polymerase Chain Reaction, Thylakoids chemistry, Thylakoids genetics, Thylakoids metabolism, Nicotiana chemistry, Nicotiana genetics, Xanthophylls chemistry, Xanthophylls metabolism, beta Carotene chemistry, beta Carotene metabolism, Carotenoids metabolism, Plants, Genetically Modified metabolism, Nicotiana metabolism
Abstract

Ketolated and hydroxylated carotenoids are high-value compounds with industrial, food, and feed applications. Chemical synthesis is currently the production method of choice for these compounds, with no amenable plant sources readily available. In this study, the 4,4' β-oxygenase ( crtW ) and 3,3' β-hydroxylase (c rtZ ) genes from Brevundimonas sp. SD-212 were expressed under constitutive transcriptional control in Nicotiana glauca , which has an emerging potential as a biofuel and biorefining feedstock. The transgenic lines produced significant levels of nonendogenous carotenoids in all tissues. In leaf and flower, the carotenoids (∼0.5% dry weight) included 0.3% and 0.48%, respectively, of nonendogenous ketolated and hydroxylated carotenoids. These were 4-ketolutein, echinenone (and its 3-hydroxy derivatives), canthaxanthin, phoenicoxanthin, 4-ketozeaxanthin, and astaxanthin. Stable, homozygous genotypes expressing both transgenes inherited the chemotype. Subcellular fractionation of vegetative tissues and microscopic analysis revealed the presence of ketocarotenoids in thylakoid membranes, not predominantly in the photosynthetic complexes but in plastoglobules. Despite ketocarotenoid production and changes in cellular ultrastructure, intermediary metabolite levels were not dramatically affected. The study illustrates the utility of Brevundimonas sp. SD-212 CRTZ and CRTW to produce ketocarotenoids in a plant species that is being evaluated as a biorefining feedstock, the adaptation of the plastid to sequester nonendogenous carotenoids, and the robustness of plant metabolism to these changes., (© 2017 American Society of Plant Biologists. All Rights Reserved.)

Published
2017
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