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Abstract - There is growing industry interest to develop the allotetraploid oilseed Brassica carinata for the production of sustainable aviation fuel. It has been proposed to cultivate it as a winter cover crop to promote sustainable farming practices and avoid any land use change associated with biofuel production. However, carinata’s late flowering and maturity have limited its potential to be adopted within Australian cropping systems. My work aims to overcome this problem via accelerating the flowering and maturity of carinata through an integrated approach combining field phenotyping, genetic transformation, and targeted genome editing.

Firstly, a genetically diverse set of carinata accessions was evaluated under field conditions over two growing seasons, revealing substantial natural variation in flowering time and maturity. This identified early maturing germplasm with potential utility for breeding. Second, a robust Agrobacterium-mediated transformation platform was developed using cotyledonary petiole explants, enabling high-frequency shoot regeneration (up to 100%) and stable transformation efficiencies of up to 12% across multiple accessions. Using this platform, a multiplex CRISPR/Cas9 system was employed to target the three homoeologous copies of the flowering repressor gene SHORT VEGETATIVE PHASE (SVP). Of 30 transgenic plants recovered, 22 carried edits in at least one SVP copy, with six lines edited at all three loci. Importantly, Cas9-free, homozygous triple-edited lines were identified in the T1 generation. Under short-day and long day conditions, all edited lines flowered earlier than wild-type and control plants. Edited lines exhibited a gradient of flowering response, with all mutants flowering earlier than wild-type plants but differing in the magnitude of earliness depending on editing status and allele combination.

By enabling the development of transgene-free, early flowering lines, this work accelerates the potential application of carinata as a winter cover crop in Australian agricultural systems. It also supports the crop’s deployment as a dual-purpose, climate-smart solution for both cover cropping and sustainable aviation fuel production. Our strategy exemplifies how precision molecular technologies can accelerate the integration of underutilized crops like carinata into sustainable agricultural systems, thereby yielding agronomic, environmental, and bioenergy co-benefits. 

Biography - Reshma Roy completed her undergraduate studies from University of Agricultural Sciences, Bangalore, India. She then completed a master’s degree in molecular biology and biotechnology at the UAS, Dharwad. During her master’s, Reshma worked with the Indian Council of Agricultural Research (ICAR), where she gained experience in molecular biology, bioinformatics, and applied agricultural research before moving to Australia in 2022 to commence her PhD. She is currently a PhD candidate at the Research School of Biology,  with the ARC Training Centre for Future Crops Development. During her PhD, she has undertaken research internships with CSIRO and the NSW Department of Primary Industries, contributing to plant transformation, tissue culture optimisation, and field phenotyping of Brassica carinata. Her research is industry aligned, including engagement with Nufarm, with a focus on adapting carinata to Australian cropping systems as a cover crop and feedstock for sustainable aviation fuel.