Induction of Reduced Photorespiratory Activity in Submersed and Amphibious Aquatic Macrophytes 1

AUTOR(ES)

Salvucci, Michael E.

RESUMO

Incubation under water in a 30 C/14-hour or 12 C/10-hour photoperiod caused the CO2 compensation points of 10 aquatic macrophytes to decrease below 25 or increase above 50 microliters CO2 per liter, respectively. Submerged and aerial leaves of two amphibious angiosperms (Myriophyllum brasiliense and Proserpinaca palustris) maintained high compensation points when incubated in air but, when the submerged or aerial leaves of Proserpinaca were incubated under water, the compensation points dropped as low as 10. This suggests that, in addition to temperature and photoperiod, some factor associated with submergence regulates the compensation point of aquatic plants. In the high-compensation point plants, photorespiration, as a percentage of net photosynthesis, was equivalent to that in terrestrial C3 plants. For Hydrilla verticillata, the decreasing CO2 compensation points (110, 40, and 10) were associated with reduced photorespiration, as indicated by decreased O2 inhibition, decreased rates of CO2 evolution into CO2-free air, and increased net photosynthetic rates.

Documentos Relacionados

• Induction of a C4-Like Mechanism of CO2 Fixation in Egeria densa, a Submersed Aquatic Species1
• Comparison of the Photosynthetic Characteristics of Three Submersed Aquatic Plants 1
• Cellulase and xylanase activity during the decomposition of three aquatic macrophytes in a tropical oxbow lagoon
• Herbicides for Rooted Aquatic Macrophytes
• Oxygen consumption owing decomposition of aquatic macrophytes