The Role of Ribulose-1,5-Bisphosphate Regeneration in the Induction Requirement of Photosynthetic CO2 Exchange under Transient Light Conditions

摘要: The temporally variable light environment of natural plant canopies presents distinct limitations to carbon assimilation, partially as a result the photosynthetic induction requirement that develops when leaves are shaded. This study was undertaken with soybean (Glycine max L.) further identify factors contributing activation state fast component during low photon flux density (PPFD) periods. Determination pool sizes reduction cycle intermediates at and upon return saturating indicated different activity arise over time course 10-minute PPFD period. Photosynthetic reillumination limited by regeneration ribulose 1,5-P2. There an increase in levels fructose 1,6-P2, sedoheptulose 1,7-P2, triose-P, ribose 5-P, 5-P pools, indicating inactivation stromal enzymes, most notably 1,6-bisphosphatase, 1,7-bisphosphatase, kinase. fast-induction important factor limiting assimilation rapid, brief transients, which decay slow minimal. may be particularly significant for upper generally experience very rapid transients.