Flavonoids exhibit fungal species and genus specific effects on the presymbiotic growth of Gigaspora and Glomus.

The effect of the flavonoids chrysin, isorhamnetin, kaempferol, luteolin, morin and rutin on pre-symbiotic growth, such as spore germination, hyphal length, hyphal branching and the formation of auxiliary cells and secondary spores, of the arbuscular mycorrhizal fungi Gigaspora rosea, G. margarita, Glomus mosseae and G. intraradices was studied. According to the effect on each fungal growth parameter, the tested compounds could be classified to be genus and/or species specific or specific, for a certain developmental stage of pre-symbiotic growth. A clear arbuscular mycorrhizal genus specific, and even species specific, effect of some flavonoids was observed. However, this specificity of a flavonoid could not be generalized but differs depending on the pre-symbiotic stage of the AM fungus. Moreover, our show that for a better understanding of the role of compounds in the AM symbiosis, studies should not be conducted only with one AM fungus looking at one fungal growth parameter such as spore germination or hyphal length, but should be wider, including several growth parameters and several AM fungi.

[1]  D. Morandi.  Occurrence of phytoalexins and phenolic compounds in endomycorrhizal interactions, and their potential role in biological control , 1996, Plant and Soil.

[2]  K. Akiyama,et al.  Isolation and identification of a phosphate deficiency-induced C-glycosylflavonoid that stimulates arbuscular mycorrhiza formation in melon roots. , 2002, Molecular plant-microbe interactions : MPMI.

[3]  Reinhold Carle,et al.  Detection of isorhamnetin glycosides in extracts of apples (Malus domestica cv. "Brettacher") by HPLC-PDA and HPLC-APCI-MS/MS. , 2002, Phytochemical analysis : PCA.

[4]  Sebastián Fracchia.  Hongos saprotrofos del suelo como microorganismos auxiliares de micorrización , 2002 .

[5]  H. Vierheilig,et al.  Signalling in arbuscular mycorrhiza: facts and hypotheses. , 2002, Advances in experimental medicine and biology.

[6]  H. Vierheilig,et al.  Flavonoid levels in roots ofMedicago sativa are modulated by the developmental stage of the symbiosis and the root colonizing arbuscular mycorrhizal fungus , 2002 .

[7]  T. Kunik,et al.  Arbuscular mycorrhizal fungal colonization. Factors involved in host recognition. , 2001, Plant physiology.

[8]  Y. Okon,et al.  The defense response elicited by the pathogen Rhizoctonia solani is suppressed by colonization of the AM-fungus Glomus intraradices. , 2001, Plant science : an international journal of experimental plant biology.

[9]  D. Santos,et al.  Foliar flavonoids of Annonaceae from Brazil: taxonomic significance. , 2000, Phytochemistry.

[10]  B. Bago,et al.  Flavonoids and arbuscular-mycorrhizal fungi. , 1998, Advances in experimental medicine and biology.

[11]  Sally E Smith and David J Read.  Mycorrhizal Symbiosis 2nd ed , 1997 .

[12]  M. Giovannetti,et al.  Analysis of factors involved in fungal recognition responses to host-derived signals by arbuscular mycorrhizal fungi , 1996 .

[13]  S. Bentivenga,et al.  A monograph of the genus Gigaspora, incorporating developmental patterns of morphological characters , 1995 .

[14]  G. Bécard.  Flavonoids are not necessary plant signal compounds in arbuscular mycorrhizal symbioses , 1995 .

[15]  Y. Piché,et al.  Hyphal growth promotion in vitro of the VA mycorrhizal fungus, Gigaspora margarita Becker & Hall, by the activity of structurally specific flavonoid compounds under CO2 -enriched conditions. , 1992, The New phytologist.

[16]  G. Bécard,et al.  Extensive In Vitro Hyphal Growth of Vesicular-Arbuscular Mycorrhizal Fungi in the Presence of CO2 and Flavonols , 1992, Applied and environmental microbiology.

[17]  M. Nair,et al.  Stimulation of vesicular‐arbuscular mycorrhiza formation and growth of white clover by flavonoid compounds , 1991 .

[18]  D. Phillips,et al.  Flavonoids Released Naturally from Alfalfa Promote Development of Symbiotic Glomus Spores In Vitro , 1991, Applied and environmental microbiology.

[19]  K. Herrmann.  On the occurrence of flavonol and flavone glycosides in vegetables , 1988 .

[20]  B. Marsh.  Measurement of Length in Random Arrangements of Lines , 1971 .

[21]  B. Mosse.  The establishment of vesicular-arbuscular mycorrhiza under aseptic conditions. , 1962, Journal of general microbiology.

[22]  J. Gerdemann.  Relation of a Large Soil-Borne Spore to Phycomycetous Mycorrhizal Infections , 1955 .