Effect of some metabolic inhibitors of oxidative phosphorylation on rooting of cuttings of Phaseolus mungo

Abstract

2,4-enhances root formation on hypocotyl cuttings made from dark-grown seedlings of Phaseolus mungo. The effect is increased by indol-3-ylacetic acid + sucrose. In the presence of indol-3-ylacetic acid + sucrose, root formation is also enhanced by sodium azide and ammonium sulphate, two non-phenolic uncouplers of oxidative phosphorylation. It appears that the enhancement in root formation by these uncoupters is due to increased respiration by removing the obligatory link to phosphorylation and, thereby, regulating the endogenous levels of adenosine triphosphate. This is also supported by the fact that root formation in this system is depressed both by cobalt which counteracts the uncoupling effect of 2,4-dinitrophenol and also by an exogenous supply of adenosine tn phosphate.