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. 1988 Mar;86(3):684–687. doi: 10.1104/pp.86.3.684

The Effect of 1,4-Dihydropyridines on the Initiation and Development of Gametophore Buds in the Moss Funaria1

Patricia A Conrad 1,2, Peter K Hepler 1
PMCID: PMC1054552  PMID: 16665970

Abstract

The plant hormone cytokinin stimulates target caulonemata of Funaria to form buds that develop into the leafy gametophyte. Previous reports have shown that increases in intracellular Ca2+ occur during hormone-activated budding concomitant with an alteration in the polarity of the organelles in the bud site. In order to ascertain the involvement of voltage-dependent Ca2+ channels in this phenomenon, we have employed dihydropyridines (DHP), compounds noted for their ability to alter Ca2+ flux through potential-sensitive channels. Addition of the DHP agonists (+)202-791 and CGP 28392 (100 micromolar) induces bud initials on every target cell including the tip cell. Application of the DHP antagonist (−)202-791, in the presence of cytokinin (1 micromolar benzyladenine), inhibits budding 96%. Similarly, nifedipine blocks cytokinin-induced budding 87% and its effect on budding can be inactivated with a pulse of ultraviolet light. These results are consistent with the idea that cytokinin induces the budding response by increasing Ca2+ entry through voltage-operated channels. We suggest that cytokinin activation of Ca2+ channels is the first action of the hormone and that subsequent cytokinin-induced mechanisms are operating to maintain budding, since DHP-induced initials rarely develop into complete buds.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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