Assistant Professor Stanford University Stanford, California, United States
Abstract: Sorghum bicolor is a biofuel crop that offers great potential because of its tolerance to drought, heat and low-cost of production as compared to other potential feedstocks. Despite yield gains through breeding, its productivity in suboptimal conditions is still limited. To avoid competition with food crops for water and land, we aim to improve Sorghum water use efficiency through genetic engineering. Water use efficiency is a complex trait, influenced by plant root architecture, leaf cell patterning, and photosynthetic efficiency and synthetic genetic circuits allow us to precisely modify each of these plant features. Although there has been significant progress in developing tools and modifying model plants, this knowledge does not always transfer to crop plants. In the past, we successfully used synthetic genetic circuits in combination with tissue-specific promoters to modify root architecture in Arabidopsis thaliana. We are now testing and optimizing these tools for the application in grass species. Through the use of transient protoplast expression in the model bioenergy grass Setaria viridis, we show that our parts can be modified in multiple aspects to drive gene expression in a predictable manner. Subsequently, we successfully built genetic circuits that implement NOT IMPLIES logic in grasses. Our initial results indicate a promising future for engineering complex traits in bioenergy grasses.
