Crassulacean acid metabolism in phalaenopsis aphrodite var. formosa during different developmental stages
Journal
ISHS Acta Horticulturae: I International Orchid Symposium
Journal Volume
878
Pages
71-78
ISBN
9789066055735
Date Issued
2010
Author(s)
Abstract
Mature Phalaenopsis is a typical CAM plant; whereas, no remarkable day/ night titratable acidity rhythm was detected at protocorm stage. The observation suggested that Phalaenopsis at its youth may undergo C3 photosynthesis pathway and lead to our hypothesis that there exists a photosynthetic transition from C3 to CAM during plant development. Phalaenopsis aphrodite var. formosa, the most important indigenous species in Taiwan, was used to analyze PEPC activity and gene expression related to such photosynthesis transition. There was no significant daily change in malate and PEPC activity from stage 0 to 2. Malate and PEPC activity showed a daily rhythm since stage 3. At stage 4, which the protocorm developed the first leaf, the typical daily CAM pattern of malate and PEPC activity was observed. Hence, stage 4 may be the photosynthesis transition period after leaf differentiation. However, the expression of PPC, encoded for PEPC, revealed a constitutional pattern in all developmental stages without day/night difference. These results suggest that PPC expression is not the key factor controlling the transformation of photosynthesis type, and genes responsible for activation of PEPC are our next targets for studying photosynthesis transition.
SDGs
Publisher
International Society for Horticultural Science
Type
conference paper