RESUMO
Liposomes entrapping fluorescein diacetate were fused with protoplasts of Datura innoxia Mill by employing polyethylene glycol (PEG) as the fusogen. Factors that influence liposome-protoplast fusion were optimized as a function of PEG-concentration and incubation duration, liposome composition and surface charge and liposome:protoplast ratio. Phosphatidylcholine-liposomes were found ideal for the objectives of the study. Fusion index based on per cent fluorescing protoplasts varied among the protoplast types. PEG-incubation duration in the fusion assay and growth ability of protoplasts to form microcalli subsequent to liposome-protoplast fusion was determined based on protoplast plating-efficiency. Plating efficiency of post-fusion protoplasts increased due to incorporation of liposome-phosphatidylcholine in the plasmamembrane of protoplasts. Results are discussed in relation to the application of liposome-protoplast fusion system in selective modification of plasmamembrane phospholipids of protoplasts.