Isolation of mesophyll and paraveinal mesophyll protoplasts from soybean leaves

Mesophyll (MP) and paraveinal mesophyll protoplasts (PVMP) have been prepared with high yields from primary and trifoliate leaves of soybean, using a Cellulase CEL or CELF and Pectolyase Y-23 enzyme mixture. The PVMP, which are specialized for nitrogen metabolism and storage, are larger than MP and contain very few chloroplasts. This gives rise to considerable difference in the buoyant density of the two protoplast types, which has been exploited to obtain pure preparations of each. The MP and PVMP preparations were free of cellular debri and were stable for several days on ice. The purity of the preparations was further indicated by radial immunodiffusion assay using antibody to a glycoprotein specifically located in the paraveinal mesophyll (PVM) vacuole.