Protoporphyrinogen oxidase as a molecular target for diphenyl ether herbicides.

Abstract

Diphenyl ether herbicides induce an accumulation of protoporphyrin IX in plant tissues. By analogy to human porphyria, the accumulation could be attributed to decreased (Mg or Fe)-chelatase or protoporphyrinogen oxidase activities. Possible effects of acifluorfen-methyl on these enzymes were investigated in isolated corn (maize, Zea mays) etioplasts, potato (Solanum tuberosum) and mouse mitochondria, and yeast mitochondrial membranes. Acifluorfen-methyl was strongly inhibitory to protoporphyrinogen oxidase activities whatever their origins [concn. causing 50% inhibition (IC50) = 4 nM for the corn etioplast enzyme]. By contrast, it was roughly 100,000 times less active on (Mg or Fe)-chelatase activities (IC50 = 80-100 microM). Our results lead us to propose protoporphyrinogen oxidase as a cellular target for diphenyl ether herbicides.

• Authors: M Matringe, J M Camadro, P Labbe, R Scalla
• Journal: The Biochemical journal (Biochem J) Vol. 260 Issue 1 Pg. 231-5 (May 15 1989) ISSN: 0264-6021 [Print] England
• PMID: 2775186 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Herbicides
• Phenyl Ethers
• Chlorophyll
• phenyl ether
• Oxidoreductases
• Oxidoreductases Acting on CH-CH Group Donors
• Protoporphyrinogen Oxidase

Topics

• Chlorophyll (biosynthesis)
• Herbicides (pharmacology)
• Oxidoreductases (antagonists & inhibitors)
• Oxidoreductases Acting on CH-CH Group Donors
• Phenyl Ethers (pharmacology)
• Protoporphyrinogen Oxidase
• Zea mays (drug effects, enzymology)