Isolation of metabolically competent protoplasts from grapevine leaves

Protoplasts were isolated from leaves of field-grown grapevines (Vitas vinifera cv. Cabernet Sauvignon and Golden Muscat) by digestion with cellulase and driselase. The protoplasts were purified by floatation on a step gradient of Percoll. Purified protoplasts exhibited light-dependent oxygen evolution of 22–34 μmol O₂/mg chlorophyll per h, which was comparable to rates of photosynthesis reported for grapevine leaves and leaf discs. The protoplasts were 90% intact based on polarographic determination of penetration of glycolate. The results indicate that the grapevine leaf protoplasts retained their photosynthetic activities and were metabolically competent.