Fusion of Plant Protoplasts: Recent Advances in Studies on Regulation of Cell Cycle, Gene Expression and in Parasexual Gene Transfer

Abstract

Since the early 1970s the technique of fusion between plant protoplasts (1–4) has become a powerful tool in genetic manipulation of higher plants. Experiments performed by fusion of protoplasts have proved that hybridization of plant species can be parasexually accomplished. Several excellent reviews of the plant somatic hybridization field have discussed different aspects of production of somatic hybrids with special emphasis on selection systems (5–12). As shown by the continuously increasing number of examples, intra- and inter-specific hybridization through protoplast fusion can result in integration of the parental diploid genomes with basically similar gene expression patterns as in the sexual hybrids (13–18). At present, the somatic hybridization with very few exceptions is restricted only to species belonging to Solanaceae family (12). Because of this limitation, any suggestion or general conclusion about the potential use of somatic cell hybridization with application in plant breeding requires that the spectrum of species included in fusion experiments be widened.