Studies on the Cytochrome Content of Phycomyces Spores during Germination

Abstract

The development of the cytochrome system of Phycomyces during the first eight hours of germination has been determined by low temperature (77 K) difference spectroscopy. In addition, following spore germination, morphological changes along with variation in oxygen uptake have been studied. During the first eight hours after spore activation, the spore projects several germ tubes and markedly increases the amount of cytochromes per mg dry weight. The rate of oxygen uptake continually increases during the first six hours and then declines. The spectral properties of mitochondria isolated from germinated spores (18h after spore activation) have also been studied. The cytochrome system appears to be the same as in germinating spores. Electron microscopy of mitochondria from germinated spores shows typical structures with well‐developed cristae. The mitochondria from the wild‐type strain exhibits absorption peaks due to carotenoids. Absorption peaks due to carotenoids were also found in dormant spores. However, the carotenoid peaks in spores are shifted to longer wavelengths relative to those in mitochondria. Copyright © 1972, Wiley Blackwell. All rights reserved