Assessing the biotechnological potential of cotton type-1 and type-2 diacylglycerol acyltransferases in transgenic systems

Authors: Shockey, Jay; PARCHURI, PRASAD - Washington State University; Thyssen, Gregory; BATES, PHILIP - Washington State University

Submitted to: Plant Physiology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2023
Publication Date: 2/27/2023
Citation: Shockey, J., Parchuri, P., Thyssen, G.N., Bates, P.D. 2023. Assessing the biotechnological potential of cotton type-1 and type-2 diacylglycerol acyltransferases in transgenic systems. Plant Physiology and Biochemistry. 196:940-951. https://doi.org/10.1016/j.plaphy.2023.02.040.
DOI: https://doi.org/10.1016/j.plaphy.2023.02.040

Interpretive Summary: Cotton is a very rare example of a commodity oilseed whose seed oils contain unusual fatty acids not found in standard vegetable oils. Many of the processes that the plant uses to produce oil in its seeds are not understood at the molecular level. This lack of understanding is an obstacle to our goals of breeding and engineering improved varieties of cotton with value-added traits. In this study, two cottton proteins were subjected to detailed analysis to assess their ability to contribute to the stated goals. Both enzymes showed promise in this regard, the results are summarized here.

Technical Abstract: The chemical and physical properties of vegetable oils are largely dictated by the ratios each contains of 4-6 common fatty acids. However, examples of plant species that accumulate from trace amounts to >90% of certain unusual fatty acids in seed triacylglycerols have been reported. Many of the general enzymatic reactions that drive both common and ususual fatty acid biosynthesis and accumulation in stored lipids are known, but which isozymes have evolved to specifically fill this role and how they coordinate in vivo is still poorly understood. Cotton (Gossypium sp.) is the very rare example of a commodity oilseed that produces biologically relevant amounts of unusual fatty acids in its seeds and other organs, in this case, called cyclopropyl fatty acids for the cyclopropane and cyclopropene moieties found in fatty acids in membrane and storage glycerolipids. Such fatty acids are useful in the synthesis of lubricants, coatings, and other types of valuable industrial feedstocks. Our project goals include engineering other types of oilseeds to produce cyclopropyl fatty acids, and to use breeding and other genetic tools to modify production in cotton itself. Toward that end, we have cloned and characterized type-1 and type-2 diacylglycerol acyltransferases from cotton and compared their biochemical properties to that of litchi (Litchi chinensis), another cyclopropyl fatty acid-producing plant. The results observed in both transgenic microbes and plants, including the effects of total cellular production and intracellular distribution of the novel fatty acids are summarized here.