CONTROL OF RESPIRATION OF BEECH MYCORRHIZAS DURING AGEING

Publisher Website
Google Scholar
Abstract
SUMMARY: A detailed examination was made of the effects of potassium phosphate, 2,4‐DNP, KCN, and mCLAM on the respiration of beech mycorrhizas during ageing. Samples were taken on nine occasions during the year and aged for 9 days. Previous results were confirmed and it was shown that the cyanide‐insensitive pathway of oxygen uptake failed to develop fully if respiration was uncoupled. The application of cyanide seemed to allow phosphorylation to proceed at site 1 and in its presence the cyanide‐insensitive pathway could develop. Cyanide and DNP applied together caused considerable inhibition presumably owing to the small development of the cyanide‐insensitive pathway. The further addition of mCLAM gave additional inhibition. mCLAM appeared also to act as if it uncoupled phosphorylation from respiration, in addition to acting as an inhibitor of the cyanide‐insensitive pathway. It is suggested, since mCLAM does not uncouple mitochondrial oxygen uptake, that it is converted in the tissue to an uncoupling compound. The significance of the control of the insensitive pathway by phosphorylation or ATP level in the tissue is discussed.