ABSTRACT
Cytokinins had to occur at concentrations higher than those needed to elicit response in the callus bioassay, but the appeal of having a more rapid response may have outweighed the decreased sensitivity. In 1974 R. M. Tetley and K. V. Thimann opened a new phase in the area of research, with their report that in senescing oat leaf tissue, the respiration affected by cytokinin treatment was resistant to cyanide.” The idea that cytokinins might act as specific inhibitors of the cyanide-resistant respiratory pathway was explored in detail through the 1980s. The idea that cytokinins might exert a growth and development role, through effects on respiration, was also suggested by researchers working with developing tissues. Anticytokinins have commonly been identified as reversible inhibitors of cytokinin-induced growth of callus tissue in the tobacco pith bioassay. An additional method by which cytokinins suppress oxidative processes in the cell is through the control of lipoxygenase.
