Measurement of free space and sorption of large molecules by cereal roots

摘要: Abstract. Large molecular weight solutes that do not penetrate the root have been used to correct for surface film in measurements with mannitol of volume Apparent Free Space (FS) bailey roots. The results are compared those obtained using other correction techniques elimination film. molecules seem be adsorbed on and kinetics adsorption differ between polyhydric alcohol or polysaccharide dextran one hand, polyether polyethylene glycol (PEG-4000) other. significance this difference is discussed relation use PEG as an osmoticum studies water relations its effect ion uptake. Although smaller PEG's FS diminish sodium uptake from 10 mol m−3 NaCl, more dilute solutions larger polymers unlikely affect nutrient solutions. Use these substances along labelled nutrients kinetic compartmentation ions roots can help distinguish associated film, crossed cell membranes into protoplast.