PT  - JOURNAL ARTICLE
AU  - Murphy, T. M.
AU  - Auh, C. K.
TI  - The Superoxide Synthases of Plasma Membrane Preparations from Cultured Rose Cells
AID  - 10.1104/pp.110.2.621
DP  - 1996 Feb 01
TA  - Plant Physiology
PG  - 621--629
VI  - 110
IP  - 2
4099  - http://www.plantphysiol.org/content/110/2/621.short
4100  - http://www.plantphysiol.org/content/110/2/621.full
SO  - Plant Physiol.1996 Feb 01; 110
AB  - Preparations of plasma membranes isolated from cultured rose (Rosa damascena Mill. cv Gloire de Guilan) cells synthesized O2- when incubated with either NADH or NADPH, as measured by an O2--specific assay based on the chemiluminescence of lucigenin. The activities were strongly dependent on the presence of Triton X-100. The Km for NADH was 159 [mu]M; that for NADPH was 19 [mu]M. Neither NADH- nor NADPH-dependent activity was inhibited by azide, an inhibitor of peroxidase, nor by antimycin A, an inhibitor of mitochondrial electron transport; both activities were inhibited by 30 to 100 nM diphenylene iodonium, an inhibitor of the mammalian NADPH oxidase. The NADH- and NADPH-dependent activities could be distinguished by detergent solubilization and ultracentrifugation: the NADH-dependent activity sedimented more easily, whereas the NADPH-dependent activity remained in suspension. One or both of these enzymes may provide the O2- seen when plant cells are exposed to pathogens or pathogen-associated elicitors; however, plasma membranes from rose cells treated with a Phytophthora elicitor had the same activity as control cells.