Metabolic Regulation of Glycolate Synthesis, Photorespiration, and Net Photosynthesis in Tobacco by L-Glutamate 1

AUTOR(ES)

Oliver, David J.

RESUMO

Experiments were undertaken to identify and characterize control mechanisms in tobacco leaf tissue which decrease the relative contribution of photorespiratory CO2 release and thereby increase net photosynthetic CO2 fixation. A number of metabolites were supplied to illuminated leaf discs and their effect on the inhibition of glycolate synthesis was measured. Glycolate accumulation, in the presence of α-hydroxy-2-pyridinemethanesulfonic acid, was inhibited in leaf discs previously floated on 30 mM solutions of either L-glutamate, L-aspartate, phospho-enolpyruvate, or glyoxylate. The effect of glutamate on glycolate synthesis, which was investigated in detail, was concentration- and time-dependent. Glycolate synthesis was inhibited about 40% by treating leaf discs with 30 mM glutamate, and the inhibition continued for more than 4 hours after the glutamate solution was removed.

Documentos Relacionados

• Regulation of breakdown and synthesis of L-glutamate decarboxylase in Clostridium perfringens.
• Postsynaptic activation at the squid giant synapse by photolytic release of L-glutamate from a 'caged' L-glutamate.
• Brain L-glutamate decarboxylase: purification and subunit structure.
• Regulatory Aspects of l-Glutamate Transport in Aspergillus nidulans
• Energy Requirement for l-Glutamate Uptake and Utilization by Hansenula subpelliculosa Cells