MITOCHONDRIA OF MYCORRHIZAL ROOTS OF FAGUS SYLVATICA

摘要: SUMMARY Mitochondria were isolated from beech mycorrhizas, by disruption of the tissue in a medium containing PVP and reducing agents, to counteract enzyme denaturing actions endogenous phenols, tannins products phenoloxidase activity. Electron microscopic examination mitochondria showed that they structurally intact, spectral analysis revealed their cytochrome composition was marked particularly high content b557. The actively respired with Krebs cycle intermediates α-ketoglutarate, malate + pyruvate succinate, exogenous NADH. In each case oxidation tightly coupled phosphorylation, ADP:O ratios obtained which indicated three sites oxidative phosphorylation associated respiration NAD-linked substrates α-ketoglutarate pyruvate, two succinate NADH. The inhibitors rotenone, antimycin A cyanide blocked electron flow at known action transport chain. Rotenone completely inhibited both but had no effect on or Oxidation four found be partially sensitive caused maximal inhibition 50–60% rate respiration. The antimycin- cyanide-insensitive abolished mCLAM. It concluded there least one fraction mitochondrial population pathway respiration, respiratory system this could best explained model chain is branched substrate oxygen, branch via cyanide-sensitive oxidase other alternate oxidase. No as substrate. Evidence presented show favoured route under phosphorylating conditions, whereas only operated when along restricted either imposition control. Some implications these findings relation physiology mycorrhizal are discussed.