Substrates respired by mitochondrial fractions of two isolates of the nematode Aphelenchus avenae and the effects of electron transport inhibitors.

Electron transport has been assayed and compared in two isolates (M and F) of the free-living (model) nematode Aphelenchus avenae. Of the substrates tested only alpha-glycerophosphate and succinate were utilised to any significant extent by both isolates. Comparative data on respiratory rates, respiratory control ratios and ADP:O ratios for various substrates are given. Succinate oxidation by isolate-F mitochondria was ca 80-90% sensitive to antimycin A while that of isolate M was almost completely refractory to antimycin A. The response to other electron transport inhibitors suggests the operation of (a) azide/cyanide sensitive, (b) azide/salicylhydroxamic acid (SHAM) insensitive but carbon monoxide sensitive and (c) SHAM-sensitive terminal oxidases to varying degrees in the mitochondria of these two isolates of A. avenae.