| Abstract: | A concentration of 10–5 M tomatine had no effect on leakagefrom, or elongation of, wheat coleoptile segments, but consistentlyreduced IAA-enhanced extension growth by c. 50 per cent. Therewas no evidence of chemical interaction between the alkaloidand the auxin in solution, and IAA action was not affected bypre-treatment for up to 3 h with 10–5 M tomatine. Studieswith 2-14C]IAA revealed that 10–5 M tomatine did notinhibit uptake of auxin into segments. The effect of pre-treatingsegments for up to 3 h with IAA could be virtually nullifiedby 10–5 M tomatine, as could also IAA-induced changesin properties of coleoptile cell walls. Results are discussedin relation to the ability of tomatine to disrupt membrane functionand to current hypotheses implicating membranes in the primaryaction of auxin. |
