Endogenous gibberellins and inhibitors in the Douglas-fir

In young needles of the Douglas-fir (Pseudotsuga menziesii) GA₉ has been shown by GC and HPLC to be the main gibberellin. As minor compounds GA₇, GA₃ and GA₈ have been tentatively identified by HPLC. In addition to the free gibberellins small amounts of GA₉ glucosyl ester and a not yet identified ester of GA₂₀ have been isolated. From the group of endogenous inhibitors ABA has been identified by GC-MS and ABA glucosyl ester by HPLC. After enzymatic hydrolysis of the ester, ABA and glucose have been quantified by GC and GOD-POD reaction giving the ratio 1:1. Another plant growth inhibitor has been identified as the methyl ester of jasmonic acid.