Investigating the role of polyols in Cladosporium fulvum during growth under hyper-osmotic stress and in planta.
The role of the large amounts of polyols accumulated by the fungal tomato pathogen, Cladosporium fulvum (syn. Fulvia fulva, Cooke) both in planta and in axenic cultures has been examined. Arabinitol and glycerol accumulated in response to hyper-osmotic stress in vitro. Mannitol levels were lower in osmo-stressed mycelium. (13)C NMR spectroscopy indicated that carbon flow from glucose to mannitol was redirected to arabinitol and glycerol in hyper-osmotic conditions. Infected tomato ( Lycopersicon esculentum Mill.) plants contained all three polyols whereas glycerol was the only polyol present in uninfected plants, suggesting that the mannitol and arabinitol were of fungal origin. Substantially higher levels of arabinitol and glycerol were present in infected plants that were subjected to a restricted watering regime compared to fully watered plants. The results suggest that a primary role of fungal arabinitol and glycerol, but not mannitol, is osmoregulation and that water acquisition is an important aspect of pathogenicity.
Clark
Anthony J
AJ
Carlsberg Laboratory, 2500 Copenhagen Valby, Denmark.
Blissett
Kerry J
KJ
Oliver
Richard P
RP
D000222:Adaptation, Physiological / Q000187:drug effects; D002247:Carbon Isotopes; D018929:Cell Culture Techniques; D002963:Cladosporium / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D009682:Magnetic Resonance Spectroscopy; D008353:Mannitol / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D011108:Polymers / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*; D014867:Water / Q000378:metabolism / Q000494:pharmacology
D002247:Carbon Isotopes; D011108:Polymers; C024617:polyol; D014867:Water; D008353:Mannitol; D012965:Sodium Chloride; D005990:Glycerol