CRIS Project: Molecular Genetics

2008 Outcomes/Impacts

Genetic load, fitness, and competition of insect resistant and tandem construct crop x weed hybrids. USDA Biotechnology Risk Assessment Research Grants Program.

Progress

We have completed experiments to assess the competition of an introgressed, insect resistant transgenic weedy relative of canola: field mustard. Competitions experiments with wheat (as a model crop) in Georgia and Tennessee indicated that introgressed hybrids containing a Bt gene did not outcompete wildtype weed, canola (transgenic or not), or non-transgenic introgressed hybrids.  To provide a control plant for the introgressed Bt weeds, we produced a directly transformed weed.  The Bt gene construct also containing a GFP marker gene for tracking was successfully transformed into two weedy accessions of field mustard and the plants analyzed.  In addition, the fitness of these plants as well as the lines we have been using for competition experiments were assessed under field conditions.  The results showed that most transgenic lines had equivalent fitness of their non-transgenic counterparts.  AFLP analysis has been completed to better understand the crop-associated DNA markers that are co-introgressed with transgenes.

Impacts

Risk assessment data useful to regulators of biotechnology were gathered from field and greenhouse experiments.  Biotechnology was shown to weaken weedy relatives, not make them weedier.  New risk assessment technologies and tools were produced.

Biocontainment via recombination: removal of transgenes from canola pollen.

Progress

The necessary transformation vectors containing the various site-specific recombinase systems were produced in the laboratories of the co-PDs on the grant, characterized with proper QC/QA and then sent to the University of Tennessee where canola transformation experiments are currently underway. We also doing proof-of-concept studies in tobacco. The goal is to assess how site-specific recombination systems will perform in excising transgenes from canola pollen.  In addition to canola, we are beginning to assess systems that could be used in bioenergy feedstocks to assure biosafety when biotechnology is implanted in feedstock improvement, such as zinc finger nucleases.  Finally we have recently filed a university disclosure for an invention,  a new class of tissue-specific apoptosis, in which proof-of-concept studies are underway.

Impacts

Risk assessment of biotechnology is aided. The mitigation of risk could be possible with the technologies created and tested.

Evolution of Weediness and Invasiveness: Molecular Genetics Approaches

Progress

The necessary transformation vectors containing the various site-specific recombinase systems were produced in the laboratories of the co-PDs on the grant, characterized with proper QC/QA and then sent to the University of Tennessee where canola transformation experiments are currently underway. The vectors were transformed into Agrobacterium in the PIs lab. We are also doing proof-of-concept studies in tobacco to assess the efficiency of these systems. Several transgenic tobacco lines were generated with Agrobacterium-mediated transformation method. T1 seeds were generated and are currently under selection process for further pollen analysis. The goal is to assess how site-specific recombination systems will perform in excising transgenes from canola pollen.  In addition to canola, we are beginning to assess systems that could be used in bioenergy feedstocks to assure biosafety when biotechnology is implanted in feedstock improvement, such as zinc finger nucleases.  Finally we have recently filed a university disclosure for an invention, a new class of tissue-specific apoptosis, in which proof-of-concept studies are underway.

Impacts

Assessing novel technologies for mitigating gene flow from transgenic crops is of interest to government regulators of biotechnology. Novel materials for risk management were produced.