title: An Improved Variant of Soybean Type 1 Diacylglycerol Acyltransferase Increases the Oil Content and Decreases the Soluble Carbohydrate Content of Soybeans.
abstract: Kinetically improved diacylglycerol acyltransferase (DGAT) variants were created to favorably alter carbon partitioning in soybean (Glycine max) seeds. Initially, variants of a type 1 DGAT from a high-oil, high-oleic acid plant seed, Corylus americana, were screened for high oil content in Saccharomyces cerevisiae Nearly all DGAT variants examined from high-oil strains had increased affinity for oleoyl-CoA, with S0.5 values decreased as much as 4.7-fold compared with the wild-type value of 0.94 µm Improved soybean DGAT variants were then designed to include amino acid substitutions observed in promising C. americana DGAT variants. The expression of soybean and C. americana DGAT variants in soybean somatic embryos resulted in oil contents as high as 10% and 12%, respectively, compared with only 5% and 7.6% oil achieved by overexpressing the corresponding wild-type DGATs. The affinity for oleoyl-CoA correlated strongly with oil content. The soybean DGAT variant that gave the greatest oil increase contained 14 amino acid substitutions out of a total of 504 (97% sequence identity with native). Seed-preferred expression of this soybean DGAT1 variant increased oil content of soybean seeds by an average of 3% (16% relative increase) in highly replicated, single-location field trials. The DGAT transgenes significantly reduced the soluble carbohydrate content of mature seeds and increased the seed protein content of some events. This study demonstrated that engineering of the native DGAT enzyme is an effective strategy to improve the oil content and value of soybeans.
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004 keith.roesler@pioneer.com knut.meyer@usa.dupont.com.
authors.forename: Keith
authors.identifier: 0000-0002-9594-1588
authors.initials: K
authors.lastname: Roesler
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Ericka
authors.identifier: 0000-0001-7530-6539
authors.initials: E
authors.lastname: Bermudez
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Changjiang
authors.identifier: 0000-0002-8056-6623
authors.initials: C
authors.lastname: Li
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Joanne
authors.identifier: 0000-0002-0078-2239
authors.initials: J
authors.lastname: Hunt
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Howard G
authors.initials: HG
authors.lastname: Damude
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Kevin G
authors.identifier: 0000-0001-5859-2393
authors.initials: KG
authors.lastname: Ripp
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: John D
authors.initials: JD
authors.lastname: Everard
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: John R
authors.initials: JR
authors.lastname: Booth
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Leandro
authors.identifier: 0000-0002-0847-5380
authors.initials: L
authors.lastname: Castaneda
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004.
authors.forename: Lizhi
authors.identifier: 0000-0002-3306-8840
authors.initials: L
authors.lastname: Feng
authors.affiliation: DuPont Pioneer, Johnston, Iowa 50131-1004 keith.roesler@pioneer.com knut.meyer@usa.dupont.com.
authors.forename: Knut
authors.identifier: 0000-0002-9534-2489
authors.initials: K
authors.lastname: Meyer
mesh_terms: D002241:Carbohydrates / Q000032:analysis; D031211:Corylus / Q000201:enzymology* / Q000235:genetics; D051048:Diacylglycerol O-Acyltransferase / Q000235:genetics* / Q000378:metabolism; D007700:Kinetics; D019301:Oleic Acid / Q000378:metabolism; D010938:Plant Oils / Q000032:analysis / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000235:genetics; D013025:Glycine max / Q000201:enzymology* / Q000235:genetics
chemical_list: D002241:Carbohydrates; D010938:Plant Oils; D010940:Plant Proteins; D019301:Oleic Acid; D051048:Diacylglycerol O-Acyltransferase