Photoregulation of fructose and glucose respiration in the intact chloroplasts of Chlamydomonas reinhardtii F-60 and spinach

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Plant Physiology; (United States)

OSTI ID:6448662

Singh, K K; Chen, Changguo; Gibbs, M ^[1]

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1. Brandeis Univ., Waltham, MA (United States)

The photoregulation of chloroplastic respiration was studied by monitoring in darkness and in light the release of [sup 14]CO[sub 2] from whole chloroplasts of Chlamydomonas reinhardtii F-60 and spinach (Spinacia oleracea L.) supplied externally with [[sup 14]C]glucose and [[sup 14]C]fructose, respectively. CO[sub 2] release was inhibited more than 90% in both chloroplasts by a light intensity of 4 W m[sup [minus]2]. Oxidants, oxaloacetate in Chlamydomonas, nitrite in spinach, and phenazine methosulfate in both chloroplasts, reversed the inhibition. The onset of the photoinhibitory effect on CO[sub 2] release was relatively rapid compared to the restoration of CO[sub 2] release following illumination. In both darkened chloroplasts, dithiothreitol inhibited release. Of the four enzymes (fructokinase, phosphoglucose isomerase, glucose-6-P dehydrogenase, and gluconate-6-P dehydrogenase) in the pathway catalyzing the release of CO[sub 2] from fructose, only glucose-6-P dehydrogenase was deactivated by light and by dithiothreitol. 33 refs., 3 figs., 4 tabs.

• DOE Contract Number: FG02-86ER13486
• OSTI ID: 6448662
• Journal Information: Plant Physiology; (United States), Journal Name: Plant Physiology; (United States) Vol. 101:4; ISSN 0032-0889; ISSN PLPHAY
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
560120 -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACETATES
ALDEHYDES
ALGAE
AZINES
BIOLOGICAL PATHWAYS
CARBOHYDRATES
CARBOXYLIC ACID SALTS
CATABOLISM
CELL CONSTITUENTS
CHLAMYDOMONAS
CHLOROPHYCOTA
CHLOROPLASTS
ENZYMES
FOOD
FRUCTOSE
GLUCOSE
HETEROCYCLIC COMPOUNDS
HEXOSES
KETONES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
METABOLISM
MICROORGANISMS
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDIZERS
PHENAZINE
PHOTOSENSITIVITY
PLANTS
PROTEINS
PYRAZINES
RESPIRATION
SACCHARIDES
SENSITIVITY
SPINACH
UNICELLULAR ALGAE
VEGETABLES