A phenylalanine in DGAT is a key determinant of oil content and composition in maize

Pioneer Hi-Bred International Inc., A DuPont Company, 7300 NW 62nd Avenue, PO Box 1004, Johnston, Iowa 50131, USA.
Nature Genetics (Impact Factor: 29.65). 04/2008; 40(3):367-72. DOI: 10.1038/ng.85
Source: PubMed

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.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Association mapping through linkage disequilibrium (LD) analysis is a powerful tool for the dissection of complex agronomic traits and for the identification of alleles that can contribute to the enhancement of a target trait. With the developments of high throughput genotyping techniques and advanced statistical approaches as well as the assembling and characterization of multiple association mapping panels, maize has become the model crop for association analysis. In this paper, we summarize progress in maize association mapping and the impacts of genetic diversity, rate of LD decay, population size, and population structure. We also review the use of candidate genes and gene-based markers in maize association mapping studies that has generated particularly promising results. In addition, we examine recent developments in genome-wide genotyping techniques that promise to improve the power of association mapping and significantly refine our understanding of the genetic architecture of complex quantitative traits. The new challenges and opportunities associated with genome-wide analysis studies are discussed. In conclusion, we review the current and future impacts of association mapping on maize improvement along with the potential benefits for poor people in developing countries who are dependent on this crop for their food security and livelihoods.
    Crop Science 03/2011; 51(2):433. DOI:10.2135/cropsci2010.04.0233 · 1.48 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Diacylglycerol acyltransferase (DGAT1; EC is the key enzyme governing the terminal step of triacylglycerol synthesis in plant seeds. The aims here were to isolate and characterize a full-length cDNA encoding DGAT1 from the sesame (Sesamum indicum L.) cultivar 'Wanzhi1' (oil content 55 +/- A 2 %; SiDGAT1); and to over-express that gene in Arabidopsis (Arabidopsis thaliana L.) and soybean (Glycine max L. Merr.). The 1,629-bp open reading frame of the SiDGAT1 cDNA encoded a protein of 543 amino acids, which showed high similarity to other plant DGAT1s. The transcript of the SiDGAT1 gene was differentially abundant among organs in sesame. The highest transcript abundance was found in the developing seeds. The expression of the SiDGAT1 cDNA driven by the cauliflower mosaic virus 35S-promoter was able to restore to near normal oil content and the fatty acid composition phenotypes of the Arabidopsis mutant AS11 (an AtDGAT1). Over-expression of SiDGAT1 in several lines of Arabidopsis thaliana 'Col 0' resulted in increases in oil content; and in seed weight. The ratio of eicosenoic acid (C20:1) was increased, whereas that of oleic acid (C18:1) was decreased in transgenic Arabidopsis plants. The SiDGAT1 was also used to transform soybean. Compared to controls, the mean increase in oil content was 1.75 and 1.39 % respectively in T2 and T3 transgenic soybean lines. Further, SiDGAT1 transcript abundance was correlated with increased seed size and 100-seed weight, but did not alter the fatty acid composition of the seed oil.
    Plant Cell Tissue and Organ Culture 11/2014; 119(2):399-410. DOI:10.1007/s11240-014-0543-z · 2.61 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: China is the original home of kiwifruit which are derived from the species complex Actinidia chinensis. A short domestication history of a little more than 100 years characterizes kiwifruit as a unique fruit crop whose cultivar improvement is heavily dependent on exploitation and selection of wild resources. Actinidia species are widespread geographically; their distributions often overlap, and hybridization between taxa is common naturally. Actinidia species that vary in ploidy and complex mixtures of cytotypes are prevalent in natural populations. Here, we review the recent emerging knowledge of natural distribution, biogeography, and population genetics in Actinidia with a particular focus on the pattern of overlapping distribution and natural hybridization among Actinidia species. Based on the comparison of the original geographical localities where most kiwifruit commercial cultivars were selected and the whole geographical range of the species complex A. chinensis, we propose that introgression breeding for new selections and cultivars of kiwifruit should utilize targeted exploration in natural hybrid zones as well as the genomic tools and related genetic resources that are becoming available to an unprecedented extent.
    Tree Genetics & Genomes 10/2014; 10(5):1113-1122. DOI:10.1007/s11295-014-0771-8 · 2.44 Impact Factor


Available from
May 23, 2014