Transgenics media preparation

Resistance to Proteolysis. As the peptides were expected to be either secreted from plant cells in transgenic plants or applied to the external surfaces of plant tissues, the extracellular proteases present in the intercellular spaces of plant tissues were considered to be most important. Accordingly, peptides were tested against crude preparations of enzymes from the extracellular fluid (ECF) of plant leaves. Extracellular fluids from leaves of maize, tobacco and potato, and spent medium from cultured plant cells produced similar results tobacco ECF was used routinely. 

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