Enhancing Energy Density in Sugarcane By Diverting Carbon Flux From Sucrose to Triacylglycerol.

Sugarcane accumulates significant amounts of sucrose in its stem.  We are exploring the prospects of diverting the carbon flux from sucrose to triacylglycerol (TAG) for increased energy density and development of an advanced biofuel. This strategy involves the analysis of combinations of gene expression cassettes for supporting biosynthesis and storage of TAG.  Sugarcane callus was induced from immature leaf rolls via direct or indirect embryogenesis and individual or multiple, unlinked constructs were co-bombarded with the selectable nptII expression cassette. Transgenic sugarcane lines were regenerated on geneticin containing culture media and transferred to soil. Replicated TAG analysis from samples of plants growing in soil and qRT-PCR analysis of individual transgenes are currently being conducted. Correlations between TAG accumulation and gene combinations and their expression levels will be presented. These data indicate the feasibility of genetically engineering the high biomass crop sugarcane to produce TAG, which can be readily used as biodiesel transportation fuel.