Open Access
Seasonal Changes in the Kinetic Parameters of a Photosynthetic Fructose-1,6-Bisphosphatase Isolated from Peltigera rufescens
Author(s) -
D. H. Brown,
K. A. Kershaw
Publication year - 1986
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.82.2.457
Subject(s) - acclimatization , photosynthesis , fructose , fructose 1,6 bisphosphatase , lichen , biology , botany , biochemistry
The kinetic parameters of the photosynthetic fructose-1,6-bisphosphatase isolated from Peltigera rufescens (Weis) Mudd. were measured on a seasonal basis and during a laboratory-induced temperature acclimation. Both the substrate affinity and Ea changed on a seasonal basis. During the summer, the Ea decreased from 91.8 to 62.3 kilojoules per mole. The K(m) fructose-1,6-bisphosphate measured at temperatures above 25 degrees C was also found to decrease by 50%. This seasonal change in K(m) can be induced by growing the lichen under appropriate conditions for 2 weeks, and is correlated to a change in the net photosynthetic rates. It is hypothesized that this change in fructose-1,6-bisphosphatase is related to the seasonal temperature acclimation process that has been previously reported in this species.