title: Zea mays: benzoxazolinone detoxification under sulfur deficiency conditions--a complex allelopathic alliance including endophytic Fusarium verticillioides.
abstract: Benzoxazolinone detoxification is similar in plants grown under sulfur deficiency conditions and in control plants grown with an optimal S supply. However, when S-deficient plants were treated with metolachlor before benzoxazolin-2(3H)-one (BOA) incubation, detoxification was reduced, as indicated by a lower accumulation of the detoxification products BOA-6-O-glucoside and glucoside carbamate and by a loss of BOA-6-OH glucosyltransfease activity. Root colonizing microorganisms and the endophytic fungus Fusarium verticillioides participated in benzoxazolinone detoxification by converting the compound to 2-acetamidophenol (AAP) or O-hydroxyphenyl malonamic acid (OHPMA), a process accompanied by the appearance of phenoxazinone. Maize roots, however, absorbed AAP and OHPMA only in traces. Absorbed traces of OHPMA stimulated maize radicle growth, and traces of AAP stimulated cress. Phenoxazinone inhibited the growth of cress radicles at concentrations higher than 500 microM, whereas maize radicles were hardly affected. F. verticillioides did not convert benzoxazolinone to any known microbial degradation product when the medium of maize seedlings was inoculated with the fungus under sterile condition. Plant-fungus interactions seem to be important in plant survival of allelopathic attacks. This study points to a complicated network of allelopathic interactions that are influenced by biotic and abiotic factors, including herbicides.
authors.affiliation: IMBIO Institut für Molekulare Physiologie und Biotechnologie der Pflanzen, Universität Bonn, Karlrobert Kreiten Str. 13, 53115, Bonn, Germany.
authors.forename: Mona
authors.initials: M
authors.lastname: Knop
authors.forename: Svea
authors.initials: S
authors.lastname: Pacyna
authors.forename: Nataliya
authors.initials: N
authors.lastname: Voloshchuk
authors.forename: Sandra
authors.initials: S
authors.lastname: Kant
authors.forename: Carmen
authors.initials: C
authors.lastname: Müllenborn
authors.forename: Ulrike
authors.initials: U
authors.lastname: Steiner
authors.forename: Martin
authors.initials: M
authors.lastname: Kirchmair
authors.forename: Heinrich W
authors.initials: HW
authors.lastname: Scherer
authors.forename: Margot
authors.initials: M
authors.lastname: Schulz
mesh_terms: D000081:Acetamides / Q000494:pharmacology; D000082:Acetaminophen / Q000378:metabolism; D001583:Benzoxazoles / Q000378:metabolism*; D005670:Fusarium / Q000378:metabolism*; D008658:Inactivation, Metabolic; D010078:Oxazines / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D036226:Seedlings / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D000081:Acetamides; D001583:Benzoxazoles; D010078:Oxazines; C020456:phenoxazinone; D000082:Acetaminophen; C017057:benzoxazolone; D013455:Sulfur; C051786:metolachlor