Respiration and the Oxidative Activity of Particulate Fractions from Developing Pepper Fruits (Capsicum Annuum L.).

Abstract

Fruit wall tissues representing 7 stages of development from immature green to full ripe pepper fruits were used. The tissue from each maturity was fractionated by differential centrifugation and the distribution of protein N in the various fractions studied. The mitochondrial fraction contained from 3 to 5% of the total protein N. Oxygen consumption and CO2 output on both a fresh weight and N basis are given for the various maturities. The rate of O2 uptake rapidly decreases from 250 [mu]l/hr/gm fresh weight for immature greens to 60 [mu]l/hr/gm for the mature greens, then, after a very slight rise, declines to a low of about 35 [mu]l/hr/gm as the fruit approaches senescence. Mitochondrial suspension isolated from the mature fruits readily oxidized TCA intermediates while those from the immature fruits did not. CoA and cocarboxylase in addition to DPN, ATP and Mg++ increased the activity from 96 to 167 [mu]l/hr/mg N in mature greens. Corresponding values for immature particles increased from 3 to 16 [alpha]l/hr/mg N.