Effect of Brassinolide and other Growth Regulators on the Germination and Growth of Pollen Tubes of Prunus avium using a Multiple Hanging-drop Assay

Abstract

A new multiple hanging-drop assay has been tested with a growth inhibitor, cycloheximide, and a growth-promoter, fusicoccin. This assay has been used to examine the growth-response of pollen-tubes of Prunus avium to brassinolide, a naturally occurring promoter of plant growth. This response is compared with that of indol-3-ylacetic acid, gibberellic acid, and kinetin. Pollen tubes responded to brassinolide and fusicoccin at 1 nM and above, a concentration one order of magnitude lower than that for indol-3-ylacetic acid and gibberellic acid. Kinetin did not stimulate growth of the pollen tubes.