Flavonoids Released Naturally from Alfalfa Promote Development of Symbiotic Glomus Spores In Vitro

作者：Siu Mui Tsai, Donald A. Phillips · 发表于：Applied and Environmental Microbiology · 年份：1991 · DOI：10.1128/aem.57.5.1485-1488.1991 · 被引用次数：245 · 研究领域：Mycorrhizal Fungi and Plant Interactions、Legume Nitrogen Fixing Symbiosis、Fungal Biology and Applications

Because flavonoids from legumes induce transcription of nodulation genes in symbiotic rhizobial bacteria, it is reasonable to test whether these compounds alter the development of vesicular-arbuscular mycorrhizal (VAM) fungi that infect those plants. Quercetin-3-O-galactoside, the dominant flavonoid released naturally from alfalfa (Medicago sativa L.) seeds, promoted spore germination of Glomus etunicatum and Glomus macrocarpum in vitro. Quercetin produced the maximum increases in spore germination, hyphal elongation, and hyphal branching in G. etunicatum at 1 to 2.5 muM concentrations. Two flavonoids exuded from alfalfa roots, 4',7-dihydroxyflavone and 4',7-dihydroxyflavanone, also enhanced spore germination of this fungal species. Formononetin, an isoflavone that is released from stressed alfalfa roots, inhibited germination of both Glomus species. These in vitro results suggest that plant flavonoids may facilitate or regulate the development of VAM symbioses and offer new hope for developing pure, plant-free cultures of VAM fungi.