While not a record for CAM plant productivity (Nobel, 1995), it is significantly higher than the productivity of many arid CAM habitats.
High productivity and photosynthetic flexibility in a CAM plant.
Carbon assimilation characteristics of the aquatic CAM plant Isoetes howellii.
Carbon uptake characteristics in two high-elevation populations oft he aquatic CAM plant Isogtes bolanderi (Isoetaceae).
This will be followed by a review of evidence for CAM in aquatic species with diel acid fluxes and associated ecological and physiological characteristics, and will conclude with a discussion of the distribution and evolution of aquatic CAM plants.
For comparison, terrestrial CAM plants commonly have [Delta][H.
Aquatic species in five genera stand out as having acid accumulation that is substantially higher than others and within the range of terrestrial CAM plants.
2) is the largest genus of aquatic CAM plants, with all 38 aquatic species tested showing substantial [Delta][H.
However, PEPC activities are substantially lower for aquatic CAM species than for terrestrial CAM plants (Dittrich et al.
In aquatic CAM plants there is no obvious selective advantage to rapid dark fixation, whereas in terrestrial species higher PEPC activity may translate into a shorter duration of stomatal opening, and thus higher water use efficiency.
Kinetic studies show many similarities between the PEPC from the aquatic CAM Littorella and terrestrial CAM plants (Groenhof et al.
aquatica (Keeley, 1998b), and, like terrestrial CAM plants lacking this enzyme (Kelly et al.