Callus Formation from Single Protoplasts of Petunia

Abstract

ISOLATED protoplasts of higher plants are becoming of greater interest as objects of plant physiology and pure and applied genetics. They have two great advantages over isolated plant cells; first, after cell wall removal protoplasts can easily take up macromolecules, small particles and viruses^1,2, which cannot readily overcome the barrier of a cell wall, and thus protoplasts allow direct modification of cell metabolism, transfer of genetic material and possibly transplanting of cell organelles. Second, protoplasts can be fused^3,4, thus allowing the combination of genotypes of different species and of distinctly differentiated cells. To obtain the maximum information from such studies, it is necessary to grow protoplasts to flowering plants, as has been reported for protoplasts of tobacco^5–7. Up till now for other plants, only nuclear^8,9 and cellular^10–12 division have been reported. We report here on successful culture of single mesophyll protoplasts from Petunia hybrida, growing to cell clusters and to proliferating callus masses.