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The Effect Of Light Conditions On Interpreting Oil Composition Engineering In Arabidopsis Seeds, Nischal Karki, Philip D. Bates

Faculty Publications

Arabidopsis thaliana is the most developed and utilized model plant. In particular, it is an excellent model for proof‐of‐concept seed oil engineering studies because it accumulates approximately 37% seed oil by weight, and it is closely related to important Brassicaceae oilseed crops. Arabidopsis can be grown under a wide variety of conditions including continuous light; however, the amount of light is strongly correlated with total seed oil accumulation. In addition, many attempts to engineer novel seed oil fatty acid compositions in Arabidopsis have reported significant reductions in oil accumulation; however, the relative reduction from the nontransgenic controls varies greatly within …

Molecular Tools Enabling Pennycress (Thlaspi Arvense) As A Model Plant And Oilseed Cash Cover Crop, Michaela Mcginn, Winthrop B. Phippen, Ratan Chopra, Sunil Bansal, Brice A. Jarvis, Mary E. Phippen, Kevin M. Dorn, Maliheh Esfahanian, Tara J. Nazarenus, Edgar B. Cahoon, Timothy P. Durrett, M. David Marks, John C. Sedbrook

Center for Plant Science Innovation: Faculty and Staff Publications

Thlapsi arvense L. (pennycress) is being developed as a profitable oilseed cover crop for the winter fallow period throughout the temperate regions of the world, controlling soil erosion and nutrients run-off on otherwise barren farmland. We demonstrate that pennycress can serve as a user-friendly model system akin to Arabidopsis that is well-suited for both laboratory and field experimentation. We sequenced the diploid genome of the spring-type Spring 32-10 inbred line (1C DNA content of 539 Mb; 2n = 14), identifying variation that may explain phenotypic differences with winter-type pennycress, as well as predominantly a one-to-one correspondence with Arabidopsis genes, …

Identification Of Bottlenecks In The Accumulation Of Cyclic Fatty Acids In Camelina Seed Oil, Xiao-Hong Yu, Rebecca E. Cahoon, Patrick J. Horn, Hai Shi, Richa R. Prakash, Yuanheng Cai, Maegan Hearney, Kent D. Chapman, Edgar B. Cahoon, Jorg Schwender, John Shanklin

Center for Plant Science Innovation: Faculty and Staff Publications

Modified fatty acids (mFA) have diverse uses; for example, cyclopropane fatty acids (CPA) are feedstocks for producing coatings, lubricants, plastics and cosmetics. The expression of mFA-producing enzymes in crop and model plants generally results in lower levels of mFA accumulation than in their natural-occurring source plants. Thus, to further our understanding of metabolic bottlenecks that limit mFA accumulation, we generated transgenic Camelina sativa lines co-expressing Escherichia coli cyclopropane synthase (EcCPS) and Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT). In contrast to transgenic CPA-accumulating Arabidopsis, CPA accumulation in camelina caused only minor changes in seed weight, germination rate, oil accumulation and seedling …

Identification And Characterization Of An Efficient Acyl-Coa:Diacylglycerol Acyltransferase 1 (Dgat1) Gene From The Microalga Chlorella Ellipsoidea, Xuejie Guo, Chengming Fan, Yuhong Chen, Jingqiao Wang, Weibo Yin, Richard R. C. Wang, Zanmin Hu

Forage and Range Research Laboratory Publications

Background: Oil in the form of triacylglycerols (TAGs) is quantitatively the most important storage form of energy for eukaryotic cells. Diacylglycerol acyltransferase (DGAT) is considered the rate-limiting enzyme for TAG accumulation. Chlorella, a unicellular eukaryotic green alga, has attracted much attention as a potential feedstock for renewable energy production. However, the function of DGAT1 in Chlorella has not been reported.

Results: A full-length cDNA encoding a putative diacylglycerol acyltransferase 1 (DGAT1, EC 2.3.1.20) was obtained from Chlorella ellipsoidea. The 2,142 bp open reading frame of this cDNA, designated CeDGAT1, encodes a protein of 713 amino acids showing …

A Multidomain Enzyme, With Glycerol-3-Phosphate Dehydrogenase And Phosphatase Activities, Is Involved In A Chloroplastic Pathway For Glycerol Synthesis In Chlamydomonas Reinhardtii, Daniela Morales-Sánchez, Yeongho Kim, Ee Leng Terng, Laura Peterson, Heriberto D. Cerutti

Center for Plant Science Innovation: Faculty and Staff Publications

Understanding the unique features of algal metabolism may be necessary to realize the full potential of algae as feedstock for the production of biofuels and biomaterials. Under nitrogen deprivation, the green alga C. reinhardtii showed substantial triacylglycerol (TAG) accumulation and up-regulation of a gene, GPD2, encoding a multidomain enzyme with a putative phosphoserine phosphatase (PSP) motif fused to glycerol-3-phosphate dehydrogenase (GPD) domains. Canonical GPD enzymes catalyze the synthesis of glycerol-3-phosphate (G3P) by reduction of dihydroxyacetone phosphate (DHAP). G3P forms the backbone of TAGs and membrane glycerolipids and it can be dephosphorylated to yield glycerol, an osmotic stabilizer and compatible …

A Thraustochytrid Diacylglycerol Acyltransferase 2 With Broad Substrate Specificity Strongly Increases Oleic Acid Content In Engineered Arabidopsis Thaliana Seeds, Chunyu Zhang, Umidjon Iskandarov, Elliott T. Klotz, Robyn L. Stevens, Rebecca E. Cahoon, Tara J. Nazarenus, Suzette L. Pereira, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty and Staff Publications

Diacylglycerol acyltransferase (DGAT) catalyses the last step in acyl-CoA-dependent triacylglycerol (TAG) biosynthesis and is an important determinant of cellular oil content and quality. In this study, a gene, designated TaDGAT2, encoding a type 2 DGAT (DGAT2)-related enzyme was identified from the oleaginous marine protist Thraustochytrium aureum. The deduced TaDGAT2 sequence contains a ~460 amino acid domain most closely related to DGAT2s from Dictyostelium sp. (45–50% identity). Recombinant TaDGAT2 restored TAG biosynthesis to the Saccharomyces cerevisiae H1246 TAG-deficient mutant, and microsomes from the complemented mutant displayed DGAT activity with C16 and C18 saturated and unsaturated fatty acyl-CoA and diacylglycerol …

A Comparison Of Internal And External Lipids Of Nondiapausing And Diapause Initiation Phase Adult Colorado Potato Beetles, Leptinotarsa Decemlineata, George D. Yocum, James S. Buckner, Charlotte L. Fatland

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The Colorado potato beetle, Leptinotarsa decemlineata, reared under diapause-inducing conditions will emerge fromthe soil as an adult and enter the diapause initiation phase, a periodwheremetabolic reserves are stockpiled before the beetles enter the nonfeeding diapause maintenance phase. Internal and external lipids were characterized during the diapause initiation phase (IP) and compared to the lipid profiles of nondiapausing adults. The primary internal lipids of both diapause IP and nondiapausing adults are triacylglycerols. Only trace amounts of internal lipids were detected in day 1 diapause IP adults. A dramatic increase in internal lipids was observed between day 7 and day 15 …

The Very-Long-Chain Hydroxy Fatty Acyl-Coa Dehydratase Pasticcino2 Is Essential And Limiting For Plant Development, Liên Bach, Louise V. Michaelson, Richard Haslam, Yannick Bellec, Lionel Gissot, Jessica Marion, Marco Da Costa, Jean-Pierre Boutin, Martine Miquel, Frédérique Tellier, Frederic Domergue, Jennifer E. Markham, Frederic Beaudoin, Johnathan A. Napier, Jean-Denis Faure

Department of Biochemistry: Faculty Publications

Very-long-chain fatty acids (VLCFAs) are synthesized as acyl-CoAs by the endoplasmic reticulum-localized elongase multiprotein complex. Two Arabidopsis genes are putative homologues of the recently identified yeast 3-hydroxy-acyl-CoA dehydratase (PHS1), the third enzyme of the elongase complex. We showed that Arabidopsis PASTICCINO2 (PAS2) was able to restore phs1 cytokinesis defects and sphingolipid long chain base overaccumulation. Conversely, the expression of PHS1 was able to complement the developmental defects and the accumulation of long chain bases of the pas2–1 mutant. The pas2–1 mutant was characterized by a general reduction of VLCFA pools in seed storage triacylglycerols, cuticular waxes, …