Uptake of charged lipid vesicles by isolated tomato protoplasts

Abstract

LIPID vesicles act as carriers of biologically active materials into animal cells^1–3. A similar role might be envisaged for vesicles, for example, in the introduction of foreign DNA into plant protoplasts in genetic modification experiments⁴, or in the initiation of virus infection in plant protoplasts⁵. The amount of DNA which enters fed protoplasts is difficult to determine as is the multiplicity of virus which initiates infection in the poly-L-ornithine (PLO) (ref. 5) and polyethylene glycol (PEG) (ref. 6) procedures. To overcome these limitations of existing methods for the introduction of materials into protoplasts, I report here a vesicle system with the potential to fuse with the negatively charged plasmalemma⁷. Single membraned (‘hollow’) vesicles were considered more suitable to combine membrane instability with large ‘load’ volume, required to facilitate carriage of large molecules/virus particles into the protoplast and to release their content synchronously within.