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Title: Lipid, membrane, and mitochondrial characteristics of Ustilago maydis following exposure to ergosterol biosynthesis inhibitors

Abstract

Pencoazole at 0.5 ..mu..g/ml inhibited ergosterol biosynthesis in U. maydis. Polar lipids of sporidia grown with 0.5 ..mu..g/ml penconazole for 7.5 or 22 hr or 1.0 ..mu..g/ml fenarimol for 7.5 hr contained more 18:2 than 18:1 fatty acids. There was usually more 18:1 than 18:2 fatty acids in polar lipids of untreated sporidia but this ratio was influenced by culture cell density. The high 18:2 to 18:1 ratio in the polar lipids from penconazole grown cells was unaffected by cell density. There was an increase in free fatty acids and these were enriched with 18:2 members in cells grown with 0.5 ..mu..g/ml penconazole for 22 hr. Unsaturation of triglycerides fatty acids did not differ appreciably from that of untreated sporidia. Untreated WT U. maydis protoplasts lysed more slowly in 0.3 M sorbitol than those prepared from WT sporidia grown for 16 hr with 1.0 ..mu..g/ml penconazole or 2.0 ..mu..g/ml fenarimol or from untreated erg-40 sporidia. Protoplasts were more permeable to crystal violet than were those from untreated WT sporidia. Mitochondria from untreated WT sporidia oxidizing pyruvate plus malate or succinate yielded higher ADP/O rations than mitochondria from erg-40 or penconazole grown WT sporidia. The mitochondrial ATPase of control cells hadmore » a Km of 0.8 mM ATP whereas the mitochondrial ATPase of penconazole grown WT and erg-40 had a Km value of 3.7 and 3.2 mM ATP, respectively. When the mitochondrial catalytic subunit of the ATPase from these mitochondria were solubilized, the Km did not differ. These studies suggest that changes in sterols and membrane fatty acids resulting from treatments with EBI fungicides cause increased membrane fluidity which affects membrane stability, permeability and activity of the mitochondrial ATPase.« less

Authors:
Publication Date:
Research Org.:
Maryland Univ., College Park (USA)
OSTI Identifier:
6859967
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; ATP-ASE; ENZYME ACTIVITY; CELL MEMBRANES; PERMEABILITY; FUNGICIDES; TOXICITY; USTILAGO; BIOSYNTHESIS; CARBOXYLIC ACIDS; DYES; ERGOSTEROL; INHIBITION; LIPIDS; MALIC ACID; MITOCHONDRIA; PLANT CELLS; PYRUVIC ACID; SPORES; SUCCINIC ACID; ACID ANHYDRASES; CELL CONSTITUENTS; DICARBOXYLIC ACIDS; ENZYMES; FUNGI; HYDROLASES; HYDROXY ACIDS; HYDROXY COMPOUNDS; KETO ACIDS; MEMBRANES; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANOIDS; PARASITES; PESTICIDES; PHOSPHOHYDROLASES; PLANTS; STEROIDS; STEROLS; SYNTHESIS; 550200* - Biochemistry

Citation Formats

Waterfield, III, W F. Lipid, membrane, and mitochondrial characteristics of Ustilago maydis following exposure to ergosterol biosynthesis inhibitors. United States: N. p., 1986. Web.
Waterfield, III, W F. Lipid, membrane, and mitochondrial characteristics of Ustilago maydis following exposure to ergosterol biosynthesis inhibitors. United States.
Waterfield, III, W F. Wed . "Lipid, membrane, and mitochondrial characteristics of Ustilago maydis following exposure to ergosterol biosynthesis inhibitors". United States.
@article{osti_6859967,
title = {Lipid, membrane, and mitochondrial characteristics of Ustilago maydis following exposure to ergosterol biosynthesis inhibitors},
author = {Waterfield, III, W F},
abstractNote = {Pencoazole at 0.5 ..mu..g/ml inhibited ergosterol biosynthesis in U. maydis. Polar lipids of sporidia grown with 0.5 ..mu..g/ml penconazole for 7.5 or 22 hr or 1.0 ..mu..g/ml fenarimol for 7.5 hr contained more 18:2 than 18:1 fatty acids. There was usually more 18:1 than 18:2 fatty acids in polar lipids of untreated sporidia but this ratio was influenced by culture cell density. The high 18:2 to 18:1 ratio in the polar lipids from penconazole grown cells was unaffected by cell density. There was an increase in free fatty acids and these were enriched with 18:2 members in cells grown with 0.5 ..mu..g/ml penconazole for 22 hr. Unsaturation of triglycerides fatty acids did not differ appreciably from that of untreated sporidia. Untreated WT U. maydis protoplasts lysed more slowly in 0.3 M sorbitol than those prepared from WT sporidia grown for 16 hr with 1.0 ..mu..g/ml penconazole or 2.0 ..mu..g/ml fenarimol or from untreated erg-40 sporidia. Protoplasts were more permeable to crystal violet than were those from untreated WT sporidia. Mitochondria from untreated WT sporidia oxidizing pyruvate plus malate or succinate yielded higher ADP/O rations than mitochondria from erg-40 or penconazole grown WT sporidia. The mitochondrial ATPase of control cells had a Km of 0.8 mM ATP whereas the mitochondrial ATPase of penconazole grown WT and erg-40 had a Km value of 3.7 and 3.2 mM ATP, respectively. When the mitochondrial catalytic subunit of the ATPase from these mitochondria were solubilized, the Km did not differ. These studies suggest that changes in sterols and membrane fatty acids resulting from treatments with EBI fungicides cause increased membrane fluidity which affects membrane stability, permeability and activity of the mitochondrial ATPase.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1986},
month = {1}
}

Thesis/Dissertation:
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