Detection and identification of gibberellins in needles of silver fir (Abies alba Mill.) by combined gas chromatography mass spectrometry

Extracts of mature silver fir (Abies alba Mill.) needles, current-year, and one-year old (A) and seven to nine-year old (B), were purified by reversed and normal phase HPLC. Gibberellin (GA)-like compounds were detected by the Tan-ginbozu dwarf rice micro-drop bioassay and corresponding fractions were analyzed by GC-MS. GA(9) was present in small amounts, while a major component was a cellulase-hydrolysable GA(9) conjugate which was assumed to be GA(9) glucosyl ester. It is proposed that GA(9) glucosyl ester plays a key role in the regulation of endogenous GA levels in silver fir needles.