A new method for the determination of phytohormone activity

Publisher Website
Google Scholar
Abstract
Evidence is obtained that the known phytohormones, responsible for growth promotion in the higher plants, exert also a stimulative effect on the rate of reproduction of yeast. The reaction is utilized as a speedy sorting test for substances suspected of phytohormone activity. The following exptl. procedure is adopted: Five 250 cc. conical flasks, each containing 95 cc. synthetic medium (KEUPO4 2 g.; MgSO4-7H2O 1 g.; CaSO4 0.2 g.; FeSO4 . 7H2O 0.1 g.; (NH4)2HPO4 2.5 g.; sucrose 25 g.; aq. dest. to 1000 cc[long dash] brought to pH 4.2 by addition of H2SO4), are sterilized by steaming. Hormone solns. of different concs. (prepd. with freshly boiled water in order to obtain them as nearly sterile as possible without applying heat) are added in 4 cc. quantities, so that final concs. in media are 0 (4 cc. sterile water added), 1/10, 1, 5, 10 ppm. respectively. Finally, 1 cc. yeast suspension is added to each flask. After taking initial counts, cultures are incubated (water bath) at 25[degree], and further counts performed after 1, 2, and 5 (or 6) days. Results are expressed in graphical form with abscissae[long dash]hormone conc., and ordinates[long dash]multiplication rate (i.e., outcrop rate/seedling rate). In general, opt. conc. of hormone is 1 ppm.; with more than 5 ppm. a repressive effect is obtained. Positive responses are obtained with [beta]-indolylacetic acid, [alpha]-naphthylacetic acid, [beta]-naphthylacetic acid, phenyl-acetic acid, [alpha]-anilinopropionic acid, [alpha]-anilinovaleric acid, [alpha]-phenylpropionic acid, [alpha]-phenylcrotonic acid, glycollic anilide, phenylglycine.

This publication has 0 references indexed in Scilit: