(a)Asexualreproduction-郑智美的Homepage.ppt

* Blastomyces dermititidis causes blastomycosis Coccidioides immitis causes coccidiomycosis Histiplasma capsulatum causes histoplasmosis hyhae Human body temp Yeast form Histidine kinase Dimorphic fungi * Fungi form beneficial associations with other speciesFungal associations: Beneficial associations with photosynthetic partners Mycorhizzal fungi 菌根 Endophytes 體內寄生型 Lichens 地衣 * Mycorhizzae菌根 Association between the hyphae of certain fungi and the roots of most seed plants More than 80% of terrestrial plants have mycorrhizae Plants receive increased supply of water and mineral nutrients Fungi get organic food molecules from the plants 2 most common types are endomycorrhizae and ectomycorrhizae * * Endomycorrhizae Fungal hyphae penetrate the spaces between root cell walls and plasma membranes and grow along the outer surface of the plasma membrane Arbuscular mycorrhizae (AM) form highly branched structures with high surface area * Ectomycorrhizae Coat root surface and grow betweencells of roots Some species of oak, beech, pine, and spruce trees will not grow unless their ectomycorrhizal partners are also present Copyright ? The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (b) SEM of ectomycorrhizal hyphae (c) Hyphae invading intercellular spaces (a) Ectomycorrhizal fruiting body Ectomycorrhizal hyphae coating a root tip Root cells Ectomycorrhizal hyphae a: ? Jacques Landry, Mycoquebec.org; b: ? Courtesy of Larry Peterson and Hugues Massicotte Gene Expression in Ectomycorrhizal Fungi Explains How They Live Both Independently and in Partnership with Plants Laccaria bicolor雙色蠟蘑model organism Mycelium grows well by itself and in symbiosis with tree roots 2008 genome study explained its characteristics L. bicolor has a larger genome than nonmycorrhizal fungi – suggests that symbiosis has accelerated evolution High number of genes associated with plasma membrane transport Lacks genetic capacity to break down cellulose and lignin * Funga