GA-003

Fourteen endophytic fungi with different colony morphologies were isolated from the roots of Calystegia soldanella. Endophytic fungi isolated from C. soldanella were identified by internal transcribed spacer (ITS) region. To verify plant growth promotion (PGP), culture filtrates of isolated endophytic fungi were treated in Waito-c rice (WR) and C. soldanella seedlings. Culture filtrates of Cs-8-1 fungal strain had advanced PGP activity. The presence of physiologically bioactive gibberellins (GA) GA(1) (1.213 ng ml(-1)), GA(3) (1.292 ng ml(-1)), GA(4) (3.6 ng ml(-1)), GA(7) (1.328 ng ml(-1)), other inactive GA(9) (0.796 ng ml(-1)) and GA(12) (0.417 ng ml(-1)), GA(20) (0.302 ng ml(-1)), GA(24) (1.351 ng ml(-1)), GA(34) (0.076 ng ml(-1)), and GA(53) (0.051 ng ml(-1)) in culture filtrates of Cs-8-1 fungal strain was detected. The Cs-8-1 fungal strain was confirmed as a producer of GAs. Molecular analysis of sequences showed high similarity of 99% to Cadophora malorum. Consequentially, the Cs-8-1 fungal strain was identified as a new C. malorum producing GAs.

The residues of gibberellic acid (GA(3)) in tea shoots, made tea, and tea infusion were determined by ultra-performance liquid chromatography tandem mass (UPLC-MS/MS) to study its degradation pattern during tea planting, processing, and brewing. The dissipation rate of GA(3) was described using first-order kinetics. Its half-life ranged from 1.67 to 2.01 days in tea shoots. Degradation and concentration during green tea processing had equally important functions on GA(3) residues in product intermediates and made tea. Except for water content, little GA(3) residue difference was found in tea shoots and made tea. GA(3) dissipated rapidly in the baking stage during processing. The transfer coefficient of GA(3) residues from made tea to infusion was from 26.23% to 54.55%. GA(3) extraction efficiency varied with different infusion times and concentrations of GA(3) in made tea. This research revealed that GA(3) may be safe when applied in tea gardens at suitable doses and picking intervals.