ABSTRACT
A fundamental difference between plant and animal cells is that certain plant cells are totipotent and can be induced to divide and develop into complete plants. Another significant difference is the presence of a cell wall in plants. Protoplast isolation by enzymatic cell wall digestion involves the use of cellulase, hemicellulase, and/or pectinase. These hydrolytic enzymes are extracted from various sources including fungi, snail, and termite gut and are available commercially in differing formulations that vary in purity. Protoplast culture has been used to develop plants with improved agronomic and horticultural characteristics and improved disease resistance through the recovery of culture-induced variants, parasexual hybrids, and genetically engineered plants. The best culture medium for protoplasts is often similar to, or slightly modified from, that used for organ regeneration from other explants. Genetic transformation of single cells has been accomplished by co-cultivating protoplasts with Agrobacterium tumefaciens or by direct DNA transfer using polycationic chemicals, electroporation, liposomes, microinjection, or sonication.
