title: A phenylalanine in DGAT is a key determinant of oil content and composition in maize.
abstract: Plant oil is an important renewable resource for biodiesel production and for dietary consumption by humans and livestock. Through genetic mapping of the oil trait in plants, studies have reported multiple quantitative trait loci (QTLs) with small effects, but the molecular basis of oil QTLs remains largely unknown. Here we show that a high-oil QTL (qHO6) affecting maize seed oil and oleic-acid contents encodes an acyl-CoA:diacylglycerol acyltransferase (DGAT1-2), which catalyzes the final step of oil synthesis. We further show that a phenylalanine insertion in DGAT1-2 at position 469 (F469) is responsible for the increased oil and oleic-acid contents. The DGAT1-2 allele with F469 is ancestral, whereas the allele without F469 is a more recent mutant selected by domestication or breeding. Ectopic expression of the high-oil DGAT1-2 allele increases oil and oleic-acid contents by up to 41% and 107%, respectively. This work provides insights into the molecular basis of natural variation of oil and oleic-acid contents in plants and highlights DGAT as a promising target for increasing oil and oleic-acid contents in other crops.
authors.affiliation: Pioneer Hi-Bred International Inc., A DuPont Company, 7300 NW 62nd Avenue, PO Box 1004, Johnston, Iowa 50131, USA.
authors.forename: Peizhong
authors.initials: P
authors.lastname: Zheng
authors.forename: William B
authors.initials: WB
authors.lastname: Allen
authors.forename: Keith
authors.initials: K
authors.lastname: Roesler
authors.forename: Mark E
authors.initials: ME
authors.lastname: Williams
authors.forename: Shirong
authors.initials: S
authors.lastname: Zhang
authors.forename: Jiming
authors.initials: J
authors.lastname: Li
authors.forename: Kimberly
authors.initials: K
authors.lastname: Glassman
authors.forename: Jerry
authors.initials: J
authors.lastname: Ranch
authors.forename: Douglas
authors.initials: D
authors.lastname: Nubel
authors.forename: William
authors.initials: W
authors.lastname: Solawetz
authors.forename: Dinakar
authors.initials: D
authors.lastname: Bhattramakki
authors.forename: Victor
authors.initials: V
authors.lastname: Llaca
authors.forename: Stéphane
authors.initials: S
authors.lastname: Deschamps
authors.forename: Gan-Yuan
authors.initials: GY
authors.lastname: Zhong
authors.forename: Mitchell C
authors.initials: MC
authors.lastname: Tarczynski
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
mesh_terms: D000595:Amino Acid Sequence; D003314:Corn Oil / Q000737:chemistry* / Q000378:metabolism; D051048:Diacylglycerol O-Acyltransferase / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009829:Oleic Acids / Q000378:metabolism; D010649:Phenylalanine / Q000235:genetics / Q000502:physiology*; D010802:Phylogeny; D030821:Plants, Genetically Modified; D040641:Quantitative Trait Loci; D012639:Seeds; D017386:Sequence Homology, Amino Acid; D003313:Zea mays / Q000201:enzymology* / Q000235:genetics*
chemical_list: D009829:Oleic Acids; D010649:Phenylalanine; D003314:Corn Oil; D051048:Diacylglycerol O-Acyltransferase