Record ID No. |
1998 |
Author(s) |
Carlsen S.C.K., Understrup A., Fomsgaard I.S., Mortensen A.G., Ravnskov S , 2008 |
Affiliation |
University of Aarhus, Faculty of Agricultural Science, Dept Integrated Pest Management, Res Ctr Flakkebjerg, D-4200 Merseburg, GERMANY |
Title |
Flavonoids in roots of white clover: interaction of arbuscular mycorrhizal fungi and a pathogenic fungus |
Source. Vol.(no):Page |
Plant and Soil.302(1-2):33-43p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry |
Sub-subjects |
Miscellaneous |
Organism |
n.a. |
Country |
GERMANY, Europe |
Abstracts |
The effects of two arbuscular mycorrhizal fungi (AMF) (Glomus mosseae and G.
Claroideum) and a pathogenic fungus (Pythium ultimum) on the production of eight flavonoids in
roots of two white clover (Trifolium repens L.) cultivars were evaluated. Quantification of AM
and pathogenic fungi in the roots showed that the AM symbiosis significantly reduced P. Ultimum
biomass and in some cases prevented infection. The flavonoid productions in clover roots varied
depending on the presence of beneficial and/or pathogenic fungi, fungal isolate or plant
cultivar. Only plants colonized with G. Claroideum showed detectable concentrations of either
coumestrol or kaempferol (cultivar-dependant). In addition, inoculation with G. Claroideum
resulted in significantly higher concentrations of coumestrol in cv. Sonja and medicarpin in cv.
Milo. A low production of coumestrol and kaempferol in mycorrhizal plants may be G.
Mosseae-specific. Only the concentrations of formononetin and daidzein increased in clover roots
in response to infection with P. Ultimum. These flavonoids are supposedly stress metabolites,
synthesized or produced from glycosides in response to pathogen infection. However, the presence
of one or both AMF significantly lowered the formononetin and daidzein concentrations, and
overruled the inductive effect of P. Ultimum. Therefore the antagonistic action of AM against the
pathogen must take place through another mechanism. |