Experimental Morphology and Morphogenesis Then and Now: A Symposium in Memory of Elizabeth G. Cutter
Peterson, Larry .
Mycoheterotrophy - unique development between achlorophyllous plants, fungi, and autotrophic hosts.
Although most plants use chlorophyll to convert the sun's energy into metabolites for growth and reproduction, approximately 400 plant species within 87 genera and 10 families lack chlorophyll. Most of these species receive all of their carbon in the form of sugars from autotrophic plants via fungal connections and are therefore referred to as mycoheterotrophs. Since the fungus and the autotrophic host do not receive obvious benefits from the mycoheterotroph these plants are cheaters or exploitive mycorrhizas. The majority of achlorophyllous monocotyledonous species are associated with arbuscular mycorrhizal fungi forming the Paris-type colonization pattern. One monocot species, Arachnitis uniflora, has several unique features in the colonization process. As well, this species forms root-borne propagules that become colonized with fungi from the parent root before they detach. The monocot family, Orchidaceae, has the largest number of mycoheterotrophic species; these are associated with ectomycorrhizal fungi. In nature, all orchid species require a fungal symbiont for germination of their 'dust seeds' and for early seedling development. Ten genera in the Monotropoideae (Ericaceae) rely on ectomycorrhizal fungi connected to photosynthetic tree species for their source of carbon. These fungi form typical ectomycorrhizas with tree partners but unusual nutrient exchange interfaces with the mycoheterotroph. All mycohetertroph species demonstrate examples of close co-ordinated development between eukaryotic symbionts.
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1 - University of Guelph, Molecular and Cellular Biology, 50 Stone Rd East, Guelph, ON, N1G 2W1, Canada
Presentation Type: Symposium or Colloquium Presentation
Location: Delaware B/Hyatt
Date: Wednesday, July 11th, 2012
Time: 9:00 AM