Photocontrol of sorghum leaf phosphoenolpyruvate carboxylase : characterization of messenger RNA and of photoreceptor.
The mechanism underlying the light effect on phosphoenolpyruvate carboxylase (PEPC) from the C(4) plant sorghum (Sorghum vulgare Pers., var Tamaran) leaves was investigated. Following exposure to light a new isozyme of PEPC, specific for the green leaf and responsible for primary CO(2) fixation in photosynthesis, was established. Northern blot experiments revealed the presence of PEPC mRNA showing a molecular weight of 3.4 kilobases. During the greening process, concomitant to enzyme activity, PEPC protein and PEPC messenger RNA amounts increased considerably. This photoresponse was shown to be under phytochrome control.
Thomas
M
M
Laboratoire de Physiologie Végétale Moléculaire, CNRS (UA No. 1128), Université de Paris-Sud, Orsay, France.
Crétin
C
C
Keryer
E
E
Vidal
J
J
Gadal
P
P