title: Genome Wide Association Mapping in Arabidopsis thaliana Identifies Novel Genes Involved in Linking Allyl Glucosinolate to Altered Biomass and Defense.
abstract: A key limitation in modern biology is the ability to rapidly identify genes underlying newly identified complex phenotypes. Genome wide association studies (GWAS) have become an increasingly important approach for dissecting natural variation by associating phenotypes with genotypes at a genome wide level. Recent work is showing that the Arabidopsis thaliana defense metabolite, allyl glucosinolate (GSL), may provide direct feedback regulation, linking defense metabolism outputs to the growth, and defense responses of the plant. However, there is still a need to identify genes that underlie this process. To start developing a deeper understanding of the mechanism(s) that modulate the ability of exogenous allyl GSL to alter growth and defense, we measured changes in plant biomass and defense metabolites in a collection of natural 96 A. thaliana accessions fed with 50 μM of allyl GSL. Exogenous allyl GSL was introduced exclusively to the roots and the compound transported to the leaf leading to a wide range of heritable effects upon plant biomass and endogenous GSL accumulation. Using natural variation we conducted GWAS to identify a number of new genes which potentially control allyl responses in various plant processes. This is one of the first instances in which this approach has been successfully utilized to begin dissecting a novel phenotype to the underlying molecular/polygenic basis.
authors.affiliation: Department of Plant Sciences, University of California, DavisDavis, CA, USA; Group of Genetics, Breeding and Biochemistry of Brassicas, Department of Plant Genetics, Misión Biológica de Galicia, Spanish Council for Scientific ResearchPontevedra, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Francisco
authors.affiliation: Department of Plant Sciences, University of California, Davis Davis, CA, USA.
authors.forename: Bindu
authors.initials: B
authors.lastname: Joseph
authors.affiliation: Department of Plant Sciences, University of California, Davis Davis, CA, USA.
authors.forename: Hart
authors.initials: H
authors.lastname: Caligagan
authors.affiliation: Department of Plant Sciences, University of California, Davis Davis, CA, USA.
authors.forename: Baohua
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Plant Sciences, University of California, Davis Davis, CA, USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Corwin
authors.affiliation: Department of Plant Sciences, University of California, Davis Davis, CA, USA.
authors.forename: Catherine
authors.initials: C
authors.lastname: Lin
authors.affiliation: Department of Plant Sciences, University of California, Davis Davis, CA, USA.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Kerwin
authors.affiliation: DynaMo Center, University of Copenhagen Copenhagen, Denmark.
authors.forename: Meike
authors.initials: M
authors.lastname: Burow
authors.affiliation: Department of Plant Sciences, University of California, DavisDavis, CA, USA; DynaMo Center, University of CopenhagenCopenhagen, Denmark.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kliebenstein
keywords: Arabidopsis; GWAS; allyl GSL; defense metabolism; novel genes; plant biomass