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An optimized genetic construct for plastid transformation of tobacco (Nicotiana tabacum) for the production of the renewable, biodegradable plastic polyhydroxybutyrate (PHB) was designed using an operon extension strategy. Bacterial genes encoding the PHB pathway enzymes were selected for use in this construct based on their similarity to the codon usage and GC content of the tobacco plastome. Regulatory elements with limited homology to the host plastome yet known to yield high levels of plastidial recombinant protein production were used to enhance the expression of the transgenes. A partial transcriptional unit, containing genes of the PHB pathway and a selectable marker gene encoding spectinomycin resistance, was flanked at the 5# end by the host plant's psbA coding sequence and at the 3# end by the host plant's 3# psbA untranslated region. This design allowed insertion of the transgenes into the plastome as an extension of the psbA operon, rendering the addition of a promoter to drive the expression of the transgenes unnecessary. Transformation of the optimized construct into tobacco and subsequent spectinomycin selection of transgenic plants yielded T0 plants that were capable of producing up to 18.8% dry weight PHB in samples of leaf tissue. These plants were fertile and produced viable seed. T1 plants producing up to 17.3% dry weight PHB in samples of leaf tissue and 8.8% dry weight PHB in the total biomass of the plant were also isolated.

The rapid assessment of metabolic engineering strategies in plants is aided by crops that provide simple, high throughput transformation systems, a sequenced genome, and the ability to evaluate the resulting plants in field trials. Camelina sativa provides all of these attributes in a robust oilseed platform. The ability to perform field evaluation of Camelina is a useful, and in some studies essential benefit that allows researchers to evaluate how traits perform outside the strictly controlled conditions of a greenhouse. In the field the plants are subjected to higher light intensities, seasonal diurnal variations in temperature and light, competition for nutrients, and watering regimes dictated by natural weather patterns, all which may affect trait performance. There are difficulties associated with the use of Camelina. The current genetic resources available for Camelina pale in comparison to those developed for the model plant Arabidopsis thaliana; however, the sequence similarity of the Arabidopsis and Camelina genomes often allows the use of Arabidopsis as a reference when additional information is needed. Camelina's genome, an allohexaploid, is more complex than other model crops, but the diploid inheritance of its three subgenomes is straightforward. The need to navigate three copies of each gene in genome editing or mutagenesis experiments adds some complexity but also provides advantages for gene dosage experiments. The ability to quickly engineer Camelina with novel traits, advance generations, and bulk up homozygous lines for small-scale field tests in less than a year, in our opinion, far outweighs the complexities associated with the crop.

Background Various databases on genetically modified organisms (GMOs) exist, all with their specific focus to facilitate access to information needed for, e. g., the assistance in risk assessment, the development of detection and identification strategies or inspection and control activities. Each database has its unique approach towards the subject. Often these databases use different terminology to describe the GMOs. For adequate GMO addressing and identification and exchange of GMO-related information it is necessary to use commonly agreed upon concepts and terminology. Result A hierarchically structured controlled vocabulary describing the genetic elements inserted into conventional GMOs, and GMOs developed by the use of gen(om)e-editing is presented: the GMO genetic element thesaurus (GMO-GET). GMO-GET can be used for GMO-related documentation, including GMO-related databases. It has initially been developed on the basis of two GMO databases, i.e. the Biosafety Clearing-House and the EUginius database. Conclusion The use of GMO-GET will enable consistent and compatible information (harmonisation), also allowing an accurate exchange of information between the different data systems and thereby facilitating their interoperability. GMO-GET can also be used to describe genetic elements that are altered in organisms obtained through current targeted genome-editing techniques.