Rapid Isolation of Mesophyll Cells from Leaves of Soybean for Photosynthetic Studies

Mesophyll cells were rapidly isolated from soybean (Glycine max [L.]) leaves using a combined Macerase enzyme-stirring technique. About 50% to 70% of the leaf cells on a chlorophyll basis from 3 grams of leaves could be isolated in 15 minutes. The cells obtained by this method were capable of high rates of photosynthesis even after storage in the dark for periods of up to 9 hours. The CO(2)-saturated rate of photosynthesis increased from 5 mum CO(2)/mg Chl.hour at 5 C to 170 mum CO(2)/mg Chl.hour at 40 C. At atmospheric CO(2) concentration, the rate varied from 5 to 55 mum CO(2)/mg Chl.hour over this temperature range. The reduced temperature response of photosynthesis at low CO(2) concentration was due to an increased Km(CO(2)) of the cells with increasing temperature. The products of photosynthesis in the isolated cells were similar to the products of leaf photosynthesis.