Evidence for surfactant solubilization of plant epicuticular wax

The solubilization of isolated, reconstituted tomato (Lycopersicon esculent um Mill.) fruit and broccoli (Brassica oleracaea var. botrytis L.) leaf epi cuticular waxes (ECW) by nonionic octylphenoxypolyethoxy ethanol surfactant (Triton X-100) was demonstrated in a model system by TLC and fluorescence analysis using pyrene as a fluorescent probe. ECW was solubilized at or abo ve the surfactant critical micelle concentration; solubilization increased with an increase in micelle concentration. As shown by the fluorescence que nching of pyrene, surfactant solubilization of the ECW increased rapidly fo r the first 12 h, then approached a plateau, increased linearly with an inc rease in temperature (22-32 degreesC), and decreased linearly with the log of the polyoxyethylene chain length (range 5-40 oxyethylenes). These data a re discussed in relation to surfactant effects on phytotoxicity and perform ance of foliar spray application of agrochemicals.