title: Comparative analysis of benzoxazinoid biosynthesis in monocots and dicots: independent recruitment of stabilization and activation functions.
abstract: Benzoxazinoids represent preformed protective and allelophatic compounds that are found in a multitude of species of the family Poaceae (Gramineae) and occur sporadically in single species of phylogenetically unrelated dicots. Stabilization by glucosylation and activation by hydrolysis is essential for the function of these plant defense compounds. We isolated and functionally characterized from the dicot larkspur (Consolida orientalis) the benzoxazinoid-specific UDP-glucosyltransferase and β-glucosidase that catalyze the enzymatic functions required to avoid autotoxicity and allow activation upon challenge by herbivore and pathogen attack. A phylogenetic comparison of these enzymes with their counterparts in the grasses indicates convergent evolution by repeated recruitment from homologous but not orthologous genes. The data reveal a great evolutionary flexibility in recruitment of these essential functions of secondary plant metabolism.
authors.affiliation: Lehrstuhl für Genetik, Wissenschaftszentrum Weihenstephan, Technische Universität München, 85354 Freising, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Dick
authors.forename: Thomas
authors.initials: T
authors.lastname: Rattei
authors.forename: Martin
authors.initials: M
authors.lastname: Haslbeck
authors.forename: Wilfried
authors.initials: W
authors.lastname: Schwab
authors.forename: Alfons
authors.initials: A
authors.lastname: Gierl
authors.forename: Monika
authors.initials: M
authors.lastname: Frey
mesh_terms: D048588:Benzoxazines / Q000378:metabolism*; D005075:Biological Evolution; D005964:Glucosyltransferases / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D006109:Poaceae / Q000201:enzymology / Q000235:genetics*; D029626:Ranunculaceae / Q000201:enzymology / Q000235:genetics*; D059467:Transcriptome; D001617:beta-Glucosidase / Q000235:genetics
chemical_list: D048588:Benzoxazines; D005964:Glucosyltransferases; D001617:beta-Glucosidase