RT Journal Article
SR Electronic
T1 Changes in Mitochondrial Respiratory Chain Components of Petunia Cells during Culture in the Presence of Antimycin A
JF Plant Physiology
JO Plant Physiol.
FD American Society of Plant Biologists
SP 617
OP 622
DO 10.1104/pp.115.2.617
VO 115
IS 2
A1 Wagner, A. M.
A1 Wagner, M. J.
YR 1997
UL http://www.plantphysiol.org/content/115/2/617.abstract
AB When petunia (Petunia hybrida Vilm, cv Rosy Morn) cells are cultured in the presence of 2 [mu]M antimycin A (AA), respiration proceeds mainly via the cyanide-resistant pathway. Cyanide-resistant respiratory rates were higher in mitochondria from AA cells than in control mitochondria. Compared with control cells, an increase in alternative oxidase protein was observed in AA cells, as well as an increase in ubiquinone (UQ) content. A change in the kinetics of succinate dehydrogenase was observed: there was a much higher activity at high UQ reduction in mitochondria from AA cells compared with control mitochondria. No changes were found for external NADH dehydrogenase kinetics. In AA cells in vivo, UQ reduction was only slightly higher than in control cells, indicating that increased electron transport via the alternative pathway can prevent high UQ reduction levels. Moreover, O2 consumption continues at a similar rate as in control cells, preventing O2 danger. These adaptations to stress conditions, in which the cytochrome pathway is restricted, apparently require, in addition to an increase in alternative oxidase protein, a new setup of the relative amounts and/or kinetic parameters of all of the separate components of the respiratory network.