LEAF BISECTION FOR THE ENZYMATIC ISOLATION OF MESOPHYLL PROTOPLASTS FROM SAINTPAULIA-IONANTHA

We describe a rapid and efficient procedure for isolating leaf mesophyll protoplasts from Saintpaulia 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 x 10(5) protoplasts g(-1) (f.m.), with 70 % viability. Protoplasts ranged in size from 50 to 100 mu m, and were derived from mostly non-photosynthetic mesophyll parenchyma.