TY - JOUR
AU - Edwards, G., E.
AB - Abstract Excised leaves of a C3-photosynthetic type, Hordeum vulgare, a C4-type, Panicum miliaceum, and an intermediate-type, Panicum milioides, were allowed to take up through their cut ends a 1 mM solution of butyl hydroxybutynoate (BHB), an irreversible inactivator of glycolate oxidase. After 30 to 60 min in BHB, extractable glycolate oxidase activity could not be detected in the distal quarter of the leaf blades. Following this pretreatment, recovery of 14C-glycolate from 14CO2 incorporated in a 10 min period was nearly maximal for each of the three plant types. Labeled glycolate was 51% of the total 14CO2 incorporated for the C3-species, 36% for the intermediate-species, and 27% for the C4-species Increased labeling of glycolate was compensated for primarily by decreased labeling of the neutral and basic fractions for the C3 and intermediate-type species. In the C4-type, label decreased primarily in the neutral and insoluble fractions, but increased in the basic fraction. A lower rate of glycolate synthesis is indicative of a lower rate of photorespiration and consistent with a lower O2/CO2 ratio present in the bundle-sheath cells of C4-plants. We conclude that both decreased glycolate synthesis and the refixation of photorespiratory-released CO2 are important in maintaining a lower rate of photorespiration in C4-plants compared to C3 plants. Intermediate glycolate synthesis in Panicum milioldes is consistent with its intermediate level of O2 inhibition of photosynthesis and intermediate rate of photorespiration. This content is only available as a PDF. © Oxford University Press
TI - Glycolate synthesis in a C3 C4 and intermediate photosynthetic plant type
JF - Plant and Cell Physiology
DO - 10.1093/oxfordjournals.pcp.a075724
DA - 1978-12-01
UR - https://www.deepdyve.com/lp/oxford-university-press/glycolate-synthesis-in-a-c3-c4-and-intermediate-photosynthetic-plant-BTXq21rgKL
SP - 1399
EP - 1405
VL - 19
IS - 8
DP - DeepDyve
ER -