title: The gene controlling the indole glucosinolate modifier1 quantitative trait locus alters indole glucosinolate structures and aphid resistance in Arabidopsis.
abstract: Glucosinolates are defensive secondary compounds that display large structural diversity in Arabidopsis thaliana and related plants. Much attention has been paid to variation in the biosynthesis of Met-derived aliphatic glucosinolates and its ecological consequences, but little is known about the genes that cause qualitative and quantitative differences in Trp-derived indole glucosinolates. We use a combination of quantitative trait locus (QTL) fine-mapping and microarray-based transcript profiling to identify CYP81F2 (At5g57220), encoding a cytochrome P450 monooxygenase, as the gene underlying Indole Glucosinolate Modifier1 (IGM1), a metabolic QTL for the accumulation of two modified indole glucosinolates, 4-hydroxy-indole-3-yl-methyl and 4-methoxy-indole-3-yl-methyl glucosinolate. We verify CYP81F2 function with two SALK T-DNA insertion lines and show that CYP81F2 catalyzes the conversion of indole-3-yl-methyl to 4-hydroxy-indole-3-yl-methyl glucosinolate. We further show that the IGM1 QTL is largely caused by differences in CYP81F2 expression, which results from a combination of cis- and trans-acting expression QTL different from known regulators of indole glucosinolate biosynthesis. Finally, we elucidate a potential function of CYP81F2 in plant-insect interactions and find that CYP81F2 contributes to defense against the green peach aphid (Myzus persicae) but not to resistance against herbivory by larvae from four lepidopteran species.
authors.affiliation: Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors.forename: Marina
authors.initials: M
authors.lastname: Pfalz
authors.forename: Heiko
authors.initials: H
authors.lastname: Vogel
authors.forename: Juergen
authors.initials: J
authors.lastname: Kroymann
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005961:Glucosinolates / Q000737:chemistry / Q000378:metabolism*; D006790:Host-Parasite Interactions; D007211:Indoles / Q000737:chemistry / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D015394:Molecular Structure; D009036:Moths; D020411:Oligonucleotide Array Sequence Analysis; D040641:Quantitative Trait Loci; D014364:Tryptophan / Q000737:chemistry / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D005961:Glucosinolates; D007211:Indoles; D007527:Isoenzymes; D014364:Tryptophan; D003577:Cytochrome P-450 Enzyme System; C541880:CYP81F2 protein, Arabidopsis