Influence of cytokinins and novel cytokinin antagonists on the senescence of detached leaves of Arabidopsis thaliana

Cytokinins N6-benzyladenine (BA) and 1-(2-chloropyridin-4-yl)-3-phenylurea (4PU-30) delayed the senescence of detached leaves (3rd to 7th leaf node) of wild and ethylene insensitive eti5 mutant of Arabidopsis thaliana. The novel anticytokinins, structural analogues of purine and phenylurea cytokinins also affected the senescence of detached rosette leaves of A. thaliana. They diminished to a significant extent the cytokinin-induced delay of chlorophyll destruction, but without a considerable difference in their action against both types of cytokinins. These results correlated with changes observed in ribonuclease (RNase) activity