STP1328: Triton X-45: A Unique Effect on Growth Regulator Sorption by and Penetration of Isolated Plant Cuticles

    Fader, RG
    Research Assistant, Michigan State University, East Lansing, MI

    Bukovac, MJ
    Professor, Michigan State University, East Lansing, MI

    Pages: 17    Published: Jan 1997


    Abstract

    A unique effect of the polyethoxylated (average 5 ethylene oxide units, EO 5) octylphenol surfactant, Triton X-45 (TX-45), on the sorption and penetration of 2- (1-naphthyl) [1-14C] acetic acid (NAA) by and through enzymatically isolated tomato fruit cuticular membranes (CM) is described. TX-45 induced an unusually marked increase in cuticular sorption (55% greater than control) of NAA relative to Triton X surfactants of lower and higher EO content. This marked enhancement of NAA sorption was associated with epicuticular and cuticular waxes, for on removal of waxes, the TX-45 — mediated increase in sorption was lost. Surprisingly, a different lot of TX-45 failed to produce similar results. Evaluation of eight lots of TX-45 (0.1 % w/v) revealed that three produced no enhancement while five increased NAA sorption. A TX-45 lot that enhanced NAA sorption also increased NAA transcuticular penetration of isolated tomato fruit CM in a finite-dose diffusion system. Again, the CM waxes played a critical role. Based on capillary gas-liquid chromatography, no obvious differences were found in the ethoxymer profile of selected nonenhancing and enhancing TX-45 surfactants that could be related to performance.

    Keywords:

    cuticular penetration, epicuticular waxes, cuticular waxes, naphthylacetic acid, sorption, finite-dose, surfactants


    Paper ID: STP13851S

    Committee/Subcommittee: E35.22

    DOI: 10.1520/STP13851S


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