Effects of Fusicoccin and Kinetin in Isolated Cotyledons of Fenugreek (Trigonella foenum-graecum L.)

Abstract

Isolated cotyledons of fenugreek (T. foenum-graecum L.) were incubated in darkness and the effects of fusicoccin and kinetin on fresh weight increase and nucleic acid content of the cotyledons, and pH changes of the medium were measured.

Both fusicoccin and kinetin stimulated fresh weight increase; KCl doubled the effect of fusicoccin but increased that of kinetin by only 20%; other salts (LiCl, NaCI, NH₄Cl) could not replace KCI. The fresh weight increase in the presence of fusicoccin and kinetin together exceeded that in the presence of either alone, over a range of fusicoccin concentrations. Nucleic acid content was increased only marginally by fusicoccin, but substantially by kinetin. In contrast, the pH of the medium was lowered significantly by fusicoccin but not (or marginally) by kinetin. With fusicoccin in the solution, the fresh weight increase was less and later inhibited by cycloheximide than with kinetin in the solution; in the absence of KCI, fusicoccin-induced fresh weight increase was especially insensitive to cycloheximide. The fresh weight increase was not inhibited at all by ethylene or by 2,4-dichlorophenoxyacetic acid with fusicoccin in the solution, but it was significantly inhibited with kinetin in the solution.