Organic acid metabolism in Sclerotinia sclerotiorum

✍ Scribed by Corsini, Dennis L. ;Tourneau, Duane

• Book ID: 104769849
• Publisher: Springer-Verlag
• Year: 1973
• Weight: 394 KB
• Volume: 90
• Category: Article
• ISSN: 0003-9276
• DOI: 10.1007/bf00424824

✦ Synopsis

Citrate synthase (EC4.1.3.7), aconitate hydratase (EC4.2.1.3), NADP specific isocitrate dehydrogenase (EC 1.1.1.42), fumarate hydratase (EC 4.2.1.2) and malate dehydrogenase (EC 1.1.1.37) were detected in cell-free preparations of Sclerotinia sclerotiorum (Lib.) D By. grown on liquid glucose-salts medium in stationary culture. Isocitrate lyase (EC 4.1.3.1) was present when the fungus grew on a carbohydrate-free medium but was not detected when the cultures grew on the glucose-salts medium. The amount of oxalate in the culture filtrate declined as the specific activity of citrate synthase and malate dehydrogenase in the mycelium declined. Increasing the initial pH of the medium resulted in an increase of the dicarboxylic acids in the culture filtrate and the specific activity of malate dehydrogenase in the myeelium. The specific reaction(s) leading to oxalic acid formation were not identified.

Sclerotinia sclerotiorum produces oxalate and several dicarboxylic acids of the TCA (tricarboxylic acid) cycle in culture medium and in infected plants (Overell, 1952; Maxwell and Lumsdcn, 1970;Vega et al.,