Regulation of cyclic photophosphorylation during ferredoxin-mediated electron transport. Effect of DCMU and the NADPH/NADP/sup +/ ratio

Journal Article · Wed Apr 01 00:00:00 EST 1987 · Plant Physiol.; (United States)

OSTI ID:6021161

Hosler, J P; Yocum, C F

Addition of ferredoxin to isolated thylakoid membranes reconstitutes electron transport from water to NADP and to O/sub 2/ (the Mehler reaction). This electron flow is coupled to ATP synthesis, and both cyclic and noncyclic electron transport drive photophosphorylation. Under conditions where the NADPH/NADP/sup +/ ratio is varied, as is the amount of ATP synthesis due to cyclic activity is also varied, as is the amount of cyclic activity which is sensitive to antimycin A. Partial inhibition of photosystem II activity with DCMU (which affects reduction of electron carriers of the interphotosystem chain) also affects the level of cyclic activity. The results of these experiments indicate that two modes of cyclic electron transfer activity, which differ in their antimycin A sensitivity, can operate in the thylakoid membrane. Regulation of these activities can occur at the level of ferredoxin and is governed by the NADPH/NADP ratio.

• Research Organization: Univ. of Michigan, Ann Arbor
• OSTI ID: 6021161
• Journal Information: Plant Physiol.; (United States), Vol. 83:4
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
FERREDOXIN
ELECTRON TRANSFER
PHOSPHORYLATION
CONTROL
ATP
BIOSYNTHESIS
ENZYME ACTIVITY
ENZYME INHIBITORS
NADP
PHOTOSYNTHESIS
PHOTOSYNTHETIC MEMBRANES
PHYSIOLOGY
SPINACH
CHEMICAL REACTIONS
COENZYMES
FOOD
MEMBRANES
METALLOPROTEINS
NUCLEOTIDES
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PLANTS
PROTEINS
SYNTHESIS
VEGETABLES
551000* - Physiological Systems