Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

Abstract

Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floatingleaved and free-floating plants exhibiting intermediate activities. Internal lacunar C0~ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal C0» concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO-concentrations are discussed in relation to the individual morphologies of the plants and the environments in which they occurred.

Time‐course of uptake of dissolved inorganic carbon through willow roots in light and in darkness

“…In a submerged plant, Eriocaulon decangulare, DIC uptake by botb roots and shoots involves CO, rather than HCO^, sinee photosynthesis at higb external pH did not exceed the rate of uncatalysed HCO^ eonversion to CO2 in the medium (Raven et al 1988). Aetivity of earbonie anhydrase in roots is also low in this species (Raven et al 1988), as in some other subtnerged maerophytes (Weaver and Wetzel 1980, Graham 1982, Salvucci and Bowes 1983, and is comparable to the activities found in the roots of terrestrial plants (Graham 1982).…”