EFE ACTIVITY IN PROTOPLASTS .1. PREPARATION OF KIWI PROTOPLASTS AND MEASUREMENT OF ITS EFE ACTIVITY

The obtaining of kiwi protoplasts and the influence of factors affecti ng it, such as pH, concentration of the hydrolytic enzymes caylase and pectolyase, concentration of sorbitol and digestion time were studied . The highest amount of protoplasts per gram of tissue were obtained b y the following digestion medium: EPPS-Tris buffer, 100 mM (pH 8.40) c ontaining caylase 0.10%, pectolyase 0.01%, Cl2Ca 10 mM and sorbitol 0. 70 M. The most appropriate digestion time was 2 h. The reproducibility of the obtaining of protoplasts was tested. It was verified that the protoplast were able to convert the 1-aminocyclopropane-1-carboxylic a cid into ethylene. The EFE activity in the protoplasts was quite high when they were obtained in the presence of I-aminocyclopropane-1-carbo xylic acid (ACC) 1 mM, but it became almost completely lost when the d igestion and washing were performed without ACC.