Pike, Carl , Sharwood, Robert , Whitney, Spencer .
Transplantation of the Rubisco large subunit from the C4 plant Amaranthus edulis into the chloroplasts of tobacco.
Manipulation of the plastome in several higher plant species has now become routine through the use of microprojectile bombardment of leaf chloroplasts. Although this technology is yet to be defined for most commercial crops, substantial advances in the manipulation of the Rubisco large subunit gene have been gained using the model plant Nicotiana tabacum. These include site directed mutagenesis [Whitney et al., Plant Physiology (1999) 121: 579-588], the full replacement of the tobacco Rubisco large subunit with that of the simple homodimeric Rubisco from Rhodospirillum rubrum [Whitney and Andrews, PNAS (2001) 98: 14738-14743], or the partial replacement with the large subunit of the hexadecameric Rubisco from Helianthus annuus [Kanevski et al., Plant Physiology (1999) 119: 133-141]. The transplanted H. annuus Rubisco large subunits could assemble with the cytosolic synthesised tobacco Rubisco small subunits to form a hybrid Rubisco enzyme. We have found that this hybrid enzyme was able to support photoautotrophic growth of plants grown in soil at elevated and ambient CO2 concentrations. This observation engendered further transplantation experiments with Rubisco large subunits from other sources. The Rubisco large subunit from the C4 plant Amaranthus edulis, which shares 92% identity with the tobacco counterpart at the amino acid level, was successfully transplanted into tobacco chloroplasts. The Amaranthus Rubisco large subunits were synthesised and assembled with the tobacco small subunits to form a hybrid enzyme. This Amaranthus-tobacco hybrid enzyme accumulated to a level of 5% of wild-type tobacco Rubisco and was unable to support growth of the transformant plants grown in soil at ambient or elevated CO2 concentrations.
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1 - Franklin and Marshall College, Biology Department, PO Box 3003, Lancaster, PA, 17604, USA
2 - Research School of Biological Sciences, Australian National University, Molecular Plant Physiology Group
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM