Induction of mRNA for Phosphoenolpyruvate Carboxylase Is Correlated with a Decrease in Shoot Water Content in
1Institut für Pflanzenphysiologie und Mikrobiologie, Freie Universität, 1 Berlin 33, Germany.
Abstract:
The abundance of mRNA specific for phosphoenolpyruvate carboxylase (PEPCase) was measured in leaves from well-watered plants of Mesembryanthemum crystallinum. Plants grown side by side in pots of four different volumes (0.16, 0.74, 2.6, 6.5 liters) were compared. The time of increase in the steady-state level of PEPCase mRNA in well-watered plants was dependent on soil volume. The larger the pot, the later PEPCase transcripts were increased. PEPCase mRNA induction started when shoot water content decreased to well below 4000% of dry weight. No positive correlation with the developmental status of the plants could be found. The data indicate that PEPCase mRNA induction in well-watered plants up to 10 weeks of age is controlled environmentally rather than developmentally.
Related Concept Videos
Adaptations that Reduce Water Loss
Responses to Drought and Flooding
Regulation of Transpiration by Stomata


