Reduced apparent photorespiration by the C/sub 3/-C/sub 4/ intermediate species, Moricandia arvensis and Panicum milioides

Journal Article · Fri Mar 01 04:00:00 EST 1985 · Plant Physiol.; (United States)

OSTI ID:5806470

Holbrook, G P; Jordan, D B; Chollet, R

The CO/sub 2//O/sub 2/ specificity factor of sucrose gradient purified ribulose 1,5-bisphosphate carboxylase/oxygenase from the C/sub 3/-C/sub 4/ intermediate plants Moricandia arvensis and Panicum milioides was similar to the respective values of the enzyme from the closely related C/sub 3/ species, Moricandia foetida and Panicum laxum. Thus, the kinetic properties of this bifunctional enzyme do not explain the reduced rates of photorespiration exhibited by either of these intermediate species. Dark/light ratios for aminoacetonitrile-sensitive /sup 14/CO/sub 2/ evolution during decarboxylation of exogenous (1-/sup 14/C) glycine by leaf discs had values of 9.0 with M. arvensis and 11.8 with P. milioides. Similar results were obtained using (1-/sup 14/C) glycolate as the exogenous photorespiratory substrate, with dark/light /sup 14/CO/sub 2/ evolution ratios for the C/sub 3/-C/sub 4/ and C/sub 3/ leaf discs averaging 6.6 and 2.0, respectively. The data suggest that P. milioides and M. arvensis are capable of a more efficient internal recycling of photorespiratory CO/sub 2/ via ribulose bisphosphate carboxylase/oxygenase than closely related C/sub 3/ plants, and that this may partially account for the reduced rates of apparent photorespiration by these intermediate species.

• Research Organization: Univ. of Nebraska, Lincoln
• DOE Contract Number: AC02-81ER10902; FG02-84ER13215
• OSTI ID: 5806470
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 77:3; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
BIOCHEMISTRY
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBON-CARBON LYASES
CARBOXY-LYASES
CARBOXYLASE
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
ENZYMES
GLYCINE
LABELLED COMPOUNDS
LYASES
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXIDOREDUCTASES
OXYGEN COMPOUNDS
OXYGENASES
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
RESPIRATION
SYNTHESIS