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Some Reactions of Isolated Corn Mitochondria Influenced by Juglone.

Authors :
KOEPPE, D. E.
Source :
Physiologia Plantarum; 1972, Vol. 27 Issue 1, p89-94, 6p, 5 Charts, 3 Graphs
Publication Year :
1972

Abstract

The effects of juglone on the uptake of O<subscript>2</subscript> by excised corn roots (Zea mays L., Wf9 cms- TxM14) and isolated corn mitochondria are reported. The O<subscript>2</subscript> uptake by excised corn roots, as measured by an O<subscript>2</subscript> electrode, was inhibited more than 90 % after a one-hour treatment of 500 µΜ juglone. Lesser inhibitions were observed with 50 µΜ and 250 µΜ juglone. In a KCl reaction medium in the absence of inorganic phosphate (Pi), juglone stimulated the rate of O<subscript>2</subscript> uptake by isolated mitochondria oxidizing NADH, succinate, or malate + pyruvate. In the presence of Pi, juglone concentrations of 3 µΜ and greater inhibited the state 3 oxidation rates of succinate and malate + pyruvate, lowered respiratory control and ADP/O ratios obtained from the oxidation of NADH, malate + pyruvate, or succinate, and reduced the coupled deposition of calcium phosphate within isolated mitochondria driven by the oxidation of malate + pyruvate. The inhibition of state 3 O<subscript>2</subscript> uptake by isolated mitochondria, an oxidative state in which electron transfer is coupled to ATP production, is seen to correlate with the inhibition affected by juglone when applied to tissues in vivo. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00319317
Volume :
27
Issue :
1
Database :
Complementary Index
Journal :
Physiologia Plantarum
Publication Type :
Academic Journal
Accession number :
13788200
Full Text :
https://doi.org/10.1111/j.1399-3054.1972.tb01142.x