photosynthesis, water stress, stomatal and non-stomatal effects
Abstract
The aim of this work was to measure the net CO2 assimilation, O2 evolution, Rubisco activity, 13C content,
actual photochemical PSII efficiency, stomatal conductance, water and osmotic potentials as well as relative
water content during increasing plant dehydration. The measurements allowed to determine vulnerability of
individual segments of complex process of photosynthesis and characterise the stomatal and non-stomatal
responses to dehydration and resistance of mechanisms of photosynthesis to gradual water stress. The
sensitiveness of stomata, osmoprotection and isotopic 13C discrimination seem to be the most interesting
parameters which act dynamically in plant acclimation to drought. They may be successfully used in
screening new genotypes with efficient water and carbon use and in quantification of threshold of deleterious
environmental effect to photosynthesis.
