Leaf bisection for the enzymatic isolation of mesophyll protoplasts fromSaintpaulia ionantha

We describe a rapid and efficient procedure for isolating leaf mesophyll protoplasts fromSaintpaulia ionantha (African violet). Because of the unusual surface properties of the leaf, efficient digestion required bisection of the lamina into abaxial and adaxial halves to expose the mesophyll. Enzymatic digestion occurred during a 3 h incubation with 2% (m/v) driselase in 0.50 M mannitol, yielding 2–3 × 10⁵ protoplasts g⁻¹ (f.m.), with 70% viability. Protoplasts ranged in size from 50 to 100μm, and were derived from mostly non-photosynthetic mesophyll parenchyma.