Effects of some chelating and phenolic substances on the growth of excised pea root segments

Several chelating substances, such as 2,2'-dipyridyl, 8-hydroxyquinoline and desferal enhanced the growth of elongating segments of excised pea root tips when cultured in the presence of 2% sucrose, but their non-chelating analogues such as 4,4'-dipyridyl and 2-hydroxyquinoline were without effect. Some phenolic substances, such as cinnamic, ferulic, chlorogenic and caffeic acids, also enhanced the growth of excised segments. In general the substances which enhanced cell elongation also enhanced the development of invertase, but generally they did not enhance the increase in peroxidase activity or have any effect on the decrease in RNA content.[(14)C]cinnamic acid was continuously incorporated into the cell walls of elongating segments from which it could only be partially removed with NaOH, pronase, or HClO4. There was some evidence that the radioactivity was transferred from the cytoplasm and not incorporated directly into the cell walls. The implications of these results are discussed.