Influence of cytokinins on growth of Phycomyces blakesleeanus and on the activities of the glyoxylate cycle enzymes isocitrate lyase and malate synthase

Abstract

Botz, T. and Hilgenberg, W, 1987, influence of cytokinins on growth of Phycomyces biakesleeanus and on the activities of the glyotylate cycle enzymes isocitrate lyase and malate synthase, -Physiol, Plant, 71; 464-470.Treatment of the 1 -f strain of Phycomyces blakesleeanus Bgff. with various cytokinins resulted in a stimulation of growth. The magnitude of growth stimulation depended on both the structure of the hormone used and the carbon source in the culture medium. Most ofthe cytokinin derivatives were active effect in glucose and oleic acid cultures. Benzyladenine (BA) and benzyladenosine stimulated the fungal growth only when oieic acid was the sole carbon source, while they had no effect in glucose cultures within the tested range of concentrations. ["CJ-BA was accumulated by the mycelium of oleic acid cultures. Therefore, differences in BA uptake hetween glucose and oleic acid cultures could account mainly for Ihe specific growth-promoting effect of BA. In oleic acid cultures isocitrate lyase (EC 4.! .3.1) and maiate synthase (EC 4.1.3.2) activities were enhanced by 40 and 34%, resf>ectively, in the presence of BA, A time course of the hormone effect suggests that BA is not involved in induction, but in the regulation of the mentioned enzymes in Phycocmyces. In contrast, acetate when presented as the sole carbon source or after addition to a glucose culture medium, induced isocitrate lyase activity. This enzyme induction was prevented by simultaneous addition of cycloheximide.

Anion-Sensitive Mg2+ ATP-Dependent Proton Pumping in Microsomal Membranes from Phycomyces blakesleeanus Bgff

“…Phycomyces blakesleeanus Bgff. a member of the Zygomycetes was chosen as a model organism because of several obvious advantages such as a thoroughly studied genetic background (10), availability of extensive metabolic data (14), and, also, its being subject to regulation by plant hormones (3,16). Apart (18).…”