ABSTRACT
Regeneration from rice protoplast cultures, particularly with some model japonica varieties, has been refined to such a point that even laboratories with limited access to sophisticated cell culture and gene transfer capabilities are able to create transgenic plants at reasonable frequencies. A number of investigators focused on different explants, including leaves, callus and root tissue, as a source of protoplasts for regeneration experiments. These early experiments, however, in concert with successes in other species, directed researchers towards identification of key variables that later proved to be crucial in developing efficient rice protoplast regeneration systems. Explants which found widespread use include mature seeds and immature embryos, anthers, microspores and pollen, spikelets as well as leaf base and sheath tissue. Procedures described for the regeneration of mature embryo-derived protoplasts were also useful in regeneration of protoplasts from suspension cultures established using immature embryos.
