title: The third naturally occurring attractant toward zoospores of phytopathogenic Aphanomyces cochlioides from the Spinacia oleracea host plant.
abstract: A bioassay-guided survey of spinach leaf constituents resulted in 5,4'-dihydroxy-3,3'-dimethoxy-6,7-methylenedioxyflavone being identified as the third naturally-occurring attractant in the host plant toward the zoospores of its pathogen, Aphanomyces cochlioides. The isolate showed attracting activity around Chromosorb W AW particles (60-80 mesh) coated with a 10(-5) M solution in a zoospore suspension. However, this activity was 1/100-1/1000 less than that of cochliophilin A, an attractant in the roots of spinach. Bioassays with the present isolate and related compounds revealed that 5,3',4'-trihydroxy-3-methoxy-6,7-methylenedioxyflavone did not possess attractant activity, but rather weak antagonistic activity toward the former two attractants from spinach.
authors.affiliation: Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan. tahara@abs.agr.hokudai.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Tahara
authors.forename: K
authors.initials: K
authors.lastname: Ohkawa
authors.forename: T
authors.initials: T
authors.lastname: Takayama
authors.forename: Y
authors.initials: Y
authors.lastname: Ogawa
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005419:Flavonoids / Q000737:chemistry*; D006868:Hydrolysis; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009868:Oomycetes / Q000737:chemistry*; D010935:Plant Diseases / Q000382:microbiology*; D018724:Spinacia oleracea / Q000382:microbiology*; D013172:Spores, Fungal / Q000737:chemistry*
chemical_list: C448741:5,4'-dihydroxy-3,3'-dimethoxy-6,7-methylenedioxyflavone; D005419:Flavonoids; D007202:Indicators and Reagents