Technology Commercialization and Partnerships | BSA 12-36: Oil Accumulation in Plant Leaves

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Category: biotechnology & health

BSA 12-36: Oil Accumulation in Plant Leaves

BNL Reference Number: BSA 12-36

Patent Status: Non-Provisional filed on July 2, 2013

Summary

Thin layer chromatography of neutral lipids

Because the ratio of vegetative tissue (non-seed tissues, e.g., leaves, stems, roots, etc.) biomass to seed tissue biomass in crop and non-crop plants is so large, it is an intuitive certainty that a small, but significant, increase in the weight percent of the fatty acid storage compounds, i.e., "oils" (triacylglycerol compounds (TAGs)) in non-seed biomass could provide an enormous boost to the amount of biodiesel that could be produced during a single growth cycle. To accomplish this one needs to first understand and then to manipulate the metabolic controls that normally limit the accumulation of fatty acids, particularly in the form of TAGs, in the vegetative tissues of plants. Over-expression and suppression of a combination of genes for lipid metabolism in plants having specific background characteristics has been found to increase the oil content of non-seed tissues.

Description

The accumulation of fatty acids in storage compounds, triacylglycerol (TAG) compounds, in non-seed tissue is accomplished by transforming parent plants having specific background traits with a combination of means to up-regulate synthesis activities and down-regulate activities that compete with the formation of TAGs. In some cases a transcription factor that controls coordination of expression of fatty acid synthesis genes is combined with various acyltransferase genes. Since starch biosynthesis competes for carbon resources with fatty acid biosynthesis, starch synthetic genes are down-regulated using RNAi, antisense, or similar approaches. Acyl CoA:diacylglycerol acyltransferases (DGAT) are over-expressed in WRI1 background plants and phospholipid:diacylglycerol acyltransferases (PDAT) are over expressed in TDG1 mutant backgrounds. In all cases, down-regulation of the starch pathway, targeting ADP-glucose pyrophosphorylase, may be used. The over-production of oleosin has been particularly useful as the protein serves to protect oil droplets from disruption and degradation. Plants targeted for manipulation of TAG accumulation in non-seed tissues include those that are already candidates for use in biofuel from biomass systems.

Benefits

While oil seed crops produce specialized fatty acids that are excellent for nutritional use and as industrial feedstock, this technology may be developed in less costly plants, particularly those that can thrive in less demanding growing conditions and which would not be considered a food crop. Biofuel from biomass is most usually considered to be the fermentation product of its starch and/or sugar content, resulting in ethanol. If a small but significant increase in the fatty acid (oil) content of the biomass is achieved, the energy density of the biomass is quite substantially improved and bio-molecules with "higher octane ratings" than ethanol can be isolated. Leafy and other non-woody biomass having elevated fatty acids could be a rich source of energy.

Applications and Industries

Renewable energy resource developers having knowledge of and capabilities in plant biotechnology may wish to add this technology to their portfolio. Any plant for which transformation technologies have been developed could be a candidate.