Effect of 2-chloroethyltrimethyl ammonium chloride on tuberization and endogenous GA3 in roots of potato cuttings

Cuttings of potato shoots treated with the plant growth retardant 2-chloroethyltrimethyl ammonium chloride (CCC) form tubers earlier and have less biologically-active gibberellin (GA)-like substances in the roots than control cuttings. The major GA-like substance in roots of potato cuttings was identified as GA₃ by gas-chromatography-mass spectrometry (GC-MS). The content of GA₃ in roots of control cuttings, estimated by GC-MS-selected ion monitoring (SIM) using 17, 17-²H]GA₃ as a quantitative internal standard, was 38.8 ng per g fresh weight (fw), and in roots of CCC-treated cuttings, in which tuberization was promoted, was 0.6 ng per g fw. Gibberellin A₁, GA₈ and GA₂₀ were also indicated as minor components of roots from both control and CCC-treated cuttings. The comparatively high GA₃ content in roots of control cuttings might be the root factor responsible for delaying tuberization in potato.Abbreviations CCC 2-chloroethyltrimethyl ammonium chloride - dw dry weight - EtOAc ethyl acetate - GA gibberellin - GC-MS-SIM gas chromatography-mass spectrometry-selected ion monitoring - HPLC high performance liquid chromatography - IAA indole-3-acetic acid - KRI Kovats' retention index - MeOH methanol - MeTMSi methyl ester trimethylsilyl ether - NAA naphthalene acetic acid - SD short day(s) - 2,4-D 2,4-dichlorophenoxy acetic acid