title: Evidence for Activation of the Oxidative Pentose Phosphate Pathway during Photosynthetic Assimilation of NO(3) but Not NH(4) by a Green Alga.
abstract: Addition of NO(3) (-) to N-limited Selenastrum minutum during photosynthesis resulted in an immediate drop in the NADPH/NADP ratio and a slower increase of the NADH/NAD ratio. These changes were accompanied by a rapid decrease in glucose-6-phosphate and increase in 6-phosphogluconate, indicating activation of glucose-6-phosphate dehydrogenase and a role for the oxidation pentose phosphate pathway during photosynthetic NO(3) (-) assimilation. In contrast, the short-term changes in pyridine nucleotides and metabolites during photosynthetic assimilation of NH(4) (+) were not consistent with a stimulation of the oxidative pentose phosphate pathway.
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
authors.forename: H C
authors.initials: HC
authors.lastname: Huppe
authors.forename: G C
authors.initials: GC
authors.lastname: Vanlerberghe
authors.forename: D H
authors.initials: DH
authors.lastname: Turpin