Fusion of two protoplasts—plant cells whose rigid cell wall has been removed—facilitates fusion of their DNA, cell organelles, bacteria, and virus. This process of somatic hybridization following isolation, culture, and fusion of protoplasts is a very significant milestone in plant-tissue culture. The unique properties of protoplasts, their ability to regenerate a cell wall and resume further cell division, and their totipotent nature has opened up further extensive possibilities in terms of plant regeneration and cell wall formation studies, genetic manipulation, and somatic hybridization. It gives a novel breeding technique to enable crosses between species and even genera. Since both nuclear and cytoplasmic material is transmitted, somatic hybridization has a much greater scope of introducing genetic variability to achieve resistance to diseases, pests, abiotic stress tolerance, improved growth characteristics, and even enhanced plant size and improved secondary metabolite constitution of the progeny.

In addition to being a gateway for fundamental and applied research, protoplast fusion has been exploited for somatic hybridization in several plants of Solanaceae such as Nicotiana, Datura, Petunia, Solanum, and Lycopersicum in addition to many more families.

Literature abounds in references to novel inter-specific, intra-specific and intergeneric hybrids made from protoplast fusion. Genetic transfer of desirable characteristics by protoplast culture furthered by recombinant DNA technology has made possible insertion and expression of desired genes in a recipient cell. Through this the flower colour of Petunia could be changed and Nicotiana hybrids became resistant to tobacco mosaic virus.