Papers by Trevor Stevenson
PNAS Nexus
The last decade has seen significant advances in the development of approaches for improving both... more The last decade has seen significant advances in the development of approaches for improving both the light harvesting and carbon fixation pathways of photosynthesis by nuclear transformation, many involving multigene synthetic biology approaches. As efforts to replicate these accomplishments from tobacco into crops gather momentum, similar diversification is needed in the range of transgenic options available, including capabilities to modify crop photosynthesis by chloroplast transformation. To address this need, here we describe the first transplastomic modification of photosynthesis in a crop by replacing the native Rubisco in potato with the faster, but lower CO2-affinity and poorer CO2/O2 specificity Rubisco from the bacterium Rhodospirillum rubrum. High level production of R. rubrum Rubisco in the potRr genotype (8 to 10 µmol catalytic sites m2) allowed it to attain wild-type levels of productivity, including tuber yield, in air containing 0.5% (v/v) CO2. Under controlled env...
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Plant Cell Reports, 2011
FtsZ1-1 and MinD plastid division-related genes were identified and cloned from Brassica oleracea... more FtsZ1-1 and MinD plastid division-related genes were identified and cloned from Brassica oleracea var. botrytis. Transgenic tobacco plants expressing BoFtsZ1-1 or BoMinD exhibited cells with either fewer but abnormally large chloroplasts or more but smaller chloroplasts relative to wild-type tobacco plants. An abnormal chloroplast phenotype in guard cells was found in BoMinD transgenic tobacco plants but not in BoFtsZ1-1 transgenic tobacco plants. Transgenic tobacco plants bearing the macro-chloroplast phenotype had 10 to 20-fold increased levels of total FtsZ1-1 or MinD, whilst the transgenic tobacco plants bearing the mini-chloroplast phenotype had lower increased FtsZ1-1 or absence of detectable MinD. We also described for the first time, plastid transformation of macro-chloroplast bearing tobacco shoots with a gene cassette allowing for expression of green fluorescent protein (GFP). Homoplasmic plastid transformants from normal chloroplast and macro-chloroplast tobacco plants expressing GFP were obtained. Both types of transformants accumulated GFP at ~6% of total soluble protein, thus indicating that cells containing macro-chloroplasts can regenerate shoots in tissue culture and can stably integrate and express a foreign gene to similar levels as plant cells containing a normal chloroplast size and number.
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Plant Biotechnology, 2015
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Metabolomics : Official journal of the Metabolomic Society, 2021
INTRODUCTION Glufosinate resistant (GR) buffalo grasses were genetically modified to resist the b... more INTRODUCTION Glufosinate resistant (GR) buffalo grasses were genetically modified to resist the broad-spectrum herbicide, glufosinate by inserting a novel pat gene into its genome. This modification results in a production of additional phosphinothricin acetyltransferase (PAT) to detoxify the deleterious effects of glufosinate. The GR grasses and its associated herbicide form a modern, weeding program, to eradicate obnoxious weeds in turf lawn without damaging the grasses at relatively low costs and labor. As with several principal crops which are genetically modified to improve agricultural traits, biosafety of the GR buffalo grasses is inevitably expected to become a public concern. For the first time, we had previously examined the metabolome of glufosinate-resistant buffalo grasses, using a GC-MS untargeted approach to assess the risk of GR as well as identify any pleotropic effects arising from the genetically modification process. In this paper, an untargeted high-resolution L...
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Microbiology Australia
Interest in the replacement of imported fossil-based fuels with home-grown, renewable and cheap s... more Interest in the replacement of imported fossil-based fuels with home-grown, renewable and cheap sources of energy spikes each time we are paying over $1.50/litre for petrol. This time, however, the danger of an energy shortage coincides with an increasing level of atmospheric CO2 and an approaching global food shortage. This all dictates an urgency for the development of a new generation of feedstocks that will not only produce biofuels or their various components, but that can also be used for feeding animals and humans and at the same time will reduce a level of atmospheric CO2. These feedstock organisms have to be grown on marginal lands not used for food crops and require low inputs of fresh water and fertiliser. Further adding to this wish list is that these feedstocks could also grow in sea water, can utilise animal and human waste and be used as fertilisers for crops. All of this will finish a portrait of algae, a group of aquatic, photosynthetic, organisms ranging in size fr...
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Metabolomics
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Journal of Inherited Metabolic Disease, Feb 1, 1983
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Biotechnology for biofuels, 2015
Numerous strategies have evolved recently for the generation of genetically modified or synthetic... more Numerous strategies have evolved recently for the generation of genetically modified or synthetic microalgae and cyanobacteria designed for production of ethanol, biodiesel and other fuels. In spite of their obvious attractiveness there are still a number of challenges that can affect their economic viability: the high costs associated with (1) harvesting, which can account for up to 50 % of the total biofuel's cost, (2) nutrients supply and (3) oil extraction. Fungal-assisted bio-flocculation of microalgae is gaining increasing attention due to its high efficiency, no need for added chemicals and low energy inputs. The implementation of renewable alternative carbon, nitrogen and phosphorus sources from agricultural wastes and wastewaters for growing algae and fungi makes this strategy economically attractive. This work demonstrates that the filamentous fungi, Aspergillus fumigatus can efficiently flocculate the unicellular cyanobacteria Synechocystis PCC 6803 and its geneticall...
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Plant Gene Research, 1991
Go to AGRIS search. Molecular biology of flavonoid pigment biosynthesis in flowers. Stevenson, TW... more Go to AGRIS search. Molecular biology of flavonoid pigment biosynthesis in flowers. Stevenson, TW (Calgene Pacific Pty Ltd., Victoria, Australia). ... Source, Molecular approaches to crop improvement, Dennis, ESLlewellyn, DJ (eds.), [nd].- ISBN 03-878-22305. p. 127-148. ...
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Alien Gene Transfer in Crop Plants, Volume 1, 2013
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Scientia Horticulturae, 2013
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Plant Science, 1999
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Journal of Inherited Metabolic Disease, 1983
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Biotechnology for Biofuels, 2014
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Bioscience Reports, 1981
Copper chloride injection of rats resulted in a 4.5- to 9-fold increase in translatable metalloth... more Copper chloride injection of rats resulted in a 4.5- to 9-fold increase in translatable metallothionein messenger RNA in the liver. Metallothionein in the translation products was identified on the basis of high cysteine and serine incorporation and absence of leucine incorporation as well as comigration with authentic zinc-induced rat-liver metallothionein on SDS-polyacrylamide gels.
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Crop residues are produced in abundance in agriculture and forestry and are a potential source of... more Crop residues are produced in abundance in agriculture and forestry and are a potential source of lignocellulosic biomass for ethanol production. Recent research has included the heterologous expression in transgenic plants of genes encoding cellulases to produce fermentable sugars from plant biomass. In this study, transgenic wheat lines were generated co-expressing the genes for an endoglucanase 1 (E1) of Acidothermus cellulolyticus and cellobiohydrolase 1 (CBH1) of Trichoderma reesei. Both genes were under the control of a wheat Rubisco small subunit promoter (RbcS). Transgenic wheat leaves accumulated apoplast targeted E1 and CBH1 proteins at levels up to 1 and 0.5% respectively of total soluble protein as determined by immunoblotting. Transgenic plants co-expressing E1 and CBH1 were analysed by a 4-methylumbelliferyl-β-D-cellobioside (MUC) assay and enzymatic activity was detected up to 92 nmol 4-MU/mg tsp/min.
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We have detected a flavonoid 3',5'-hydroxylase (F3',5'H) in the microsomal fracti... more We have detected a flavonoid 3',5'-hydroxylase (F3',5'H) in the microsomal fraction of Petunia hybrida flowers. Activity varied with the development of flowers, peaking immediately prior to and during anthesis, but was absent in mature flowers. F3',5'H activity in flower extracts from genetically defined floral color mutants correlated strictly with the genotypes Hfl and Hf2. No activity was detected in flowers
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Biochimica Et Biophysica Acta-molecular Basis of Disease, 1991
The concentrations of copper, zinc and metallothionein-I (MT-I) mRNA were determined in the liver... more The concentrations of copper, zinc and metallothionein-I (MT-I) mRNA were determined in the liver, kidney and brain of the brindled mutant mouse from birth until the time of death. Despite accumulation of copper in the kidney of the mutant, MT-I mRNA concentrations were normal. There was no difference between the MT-I mRNA in the brain of mutant and normal in the first 10 days of life, but after day 10 metallothionein mRNA levels were increased in the mutant. The concentration of copper was very low in the liver of the mutant, and on day 6 after birth the metallothionein mRNA was also reduced by about 50%. This reduction was not seen in copper-deficient 6-day-old pups, despite very low hepatic copper levels. This suggests that the lower hepatic MT-I mRNA in the day 6 brindled mouse was not simply due to the reduction in hepatic copper and also that hepatic copper is not regulating metallothionein gene expression the liver of neonatal mice. After day 12 hepatic MT-I mRNA levels were elevated in mutant and in copper deficient mice, both of which die at 14 to 16 days. These increases and the increase in brain MT-I mRNA in older mutant mice are likely to be caused by stress. Overall the results support the conclusions that the brindled mutation does not cause a constitutive activation of the metallothionein genes, and that the differences in metallothionein mRNA between mutant and normal are most probably secondary consequences of the mutation.
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Biotechnology for Biofuels, 2015
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Journal of Sustainable Bioenergy Systems, 2014
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Papers by Trevor Stevenson