Flavonoids in roots of white clover: interaction of arbuscular mycorrhizal fungi and a pathogenic fungus
Flavonoids in roots of white clover: interaction of arbuscular mycorrhizal fungi and a pathogenic fungus
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DOI：
10.1007/s11104-007-9452-9
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发表时间：
2008-01-01
期刊：
影响因子：
4.9
通讯作者：
Ravnskov, S.
中科院分区：
文献类型：
--
作者：
Carlsen, S. C. K.;Understrup, A.;Ravnskov, S.
研究了两种丛枝菌根真菌（Glomus mosseae和G. claroideum）和一种病原菌（Pythium ultimum）对两种白三叶草（Trifolium repens L.）根中8种黄酮类化合物产生的影响。根内AM与病原菌的定量分析表明，AM与根内AM的共生关系显著降低了黄顶霉的生物量，在某些情况下还能预防感染。三叶草根中黄酮类化合物的产生取决于有益和/或致病真菌、真菌分离物或植物品种的存在。只有被冠状芽孢菌定殖的植物中，可检测到库米醇和山奈酚的浓度（依品种而定）。此外，接种克氏弧菌可显著提高谷氨醇浓度。Sonja和medicarpin在cv里。米洛。菌根植物中苦氨醇和山奈酚的低产量可能是G. mossee特有的。三叶草根中只有刺芒柄花素和大豆苷元的浓度随着感染而升高。这些类黄酮被认为是应激代谢物，在对病原体感染的反应中由糖苷合成或产生。然而，一种或两种AMF的存在显著降低了刺芒柄花素和大豆苷元的浓度，并抵消了紫菀的诱导作用。因此，AM对病原体的拮抗作用必须通过另一种机制进行。
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.