TY - JOUR
T1 - Role of isoflavonoids in resistance of subterranean clover trifoliates to the redlegged earth mite Halotydeus destructor
AU - Wang, S.F.
AU - Ridsdill-Smith, T.J.
AU - Ghisalberti, Emilio
PY - 1998
Y1 - 1998
N2 - Mature leaves of variety SE014 of Trifolium subterraneum are resistant to the redlegged earth mite (Halotydeus destructor). Compounds with feeding deterrent activity present in the leaves were isolated and identified by using a membrane bioassay technique. The free isoflavones, formononetin, genistein, and biochanin A, their corresponding 7-O-glucosides, and biochanin A 7-O-glucoside-6 "-O-malonate and genistein 7-O-glucoside-6 "-O-malonate, were active. In addition, the biosynthetic precursors of formononetin and genistein, 2,5,7-trihydroxy-4'-methoxyisoflavanol and 2,5,7,4'-tetrahydroxyisoflavanol, also were deterrent to the redlegged mites. The relative activity of these compounds was determined and some structure-activity correlations are noted. The constitutive defense mechanism that contributes to the resistance of subclover trifoliates to the mite contrasts with the induced chemical mechanism previously found for subterranean clover cotyledons.
AB - Mature leaves of variety SE014 of Trifolium subterraneum are resistant to the redlegged earth mite (Halotydeus destructor). Compounds with feeding deterrent activity present in the leaves were isolated and identified by using a membrane bioassay technique. The free isoflavones, formononetin, genistein, and biochanin A, their corresponding 7-O-glucosides, and biochanin A 7-O-glucoside-6 "-O-malonate and genistein 7-O-glucoside-6 "-O-malonate, were active. In addition, the biosynthetic precursors of formononetin and genistein, 2,5,7-trihydroxy-4'-methoxyisoflavanol and 2,5,7,4'-tetrahydroxyisoflavanol, also were deterrent to the redlegged mites. The relative activity of these compounds was determined and some structure-activity correlations are noted. The constitutive defense mechanism that contributes to the resistance of subclover trifoliates to the mite contrasts with the induced chemical mechanism previously found for subterranean clover cotyledons.
U2 - 10.1023/A:1020789710706
DO - 10.1023/A:1020789710706
M3 - Article
VL - 24
SP - 2089
EP - 2100
JO - Journal of Chemical Ecology
JF - Journal of Chemical Ecology
IS - 12
ER -