| Popis: |
Mesophyll cells from leaves of cowpea (Vigna unquiculata (L.) Walp.) plants, grown in salinized nutrient solution or under soil moisture tensions, were isolated and used for the determination of photosynthetic CO2 fixation rate. Maximal CO2 fixation was obtained when the osmotic potential of both isolation and CO2 fixation assay media were close to leaf osmotic potential, yielding zero turgor pressure. No decrease in photosynthesis was obtained for NaCl concentrations up to 87 moles per cubic meter in the growing medium. However, a decrease of over 50% was obtained at a similar level of soil matrix potential. The light response curve of cells from low-salinity-grown plants was similar to the controls. Cells were close to CO2 saturation at 5 mmol NaHCO3 in the medium, regardless of environmental conditions. |
