ENDOGENOUS GIBBERELLINS IN FOLIAGE OF TOMATO (LYCOPERSICON-ESCULENTUM)

Endogenous gibberellins (GAs) from the leaves and shoot tips of 13-14 days old tomato transplants (Lycopersicon esculentum Mill.) grown in s olarised or non-solarised soil were analysed by GC-mass spectrometry. Full-scan mass spectra and Kovats retention indices, revealed in plant s from both soils the presence of GA(1), GA(3), GA(3)-isolactone, GA(4 ), GA(8),GA(19), GA(20), GA(29), GA(34) and GA(51). Further analyses b y GC-SIM indicated the presence of GA(44) and GA(53) in the tomato fol iage. An isotope-dilution analysis revealed that most of the GA(3)-iso lactone was a methodological artefact. Our results provide the first c onclusive identification of most members of the early-13-hydroxylation biosynthetic pathway in vegetative tomato tissues. In addition, the p resence of GA(4), GA(34) and GA(51) which were not reported previously in the tomato, indicates that the early-non-3,13-hydroxylation biosyn thetic pathway is also active. Three potentially active GAs: GA(1), GA (3) and GA(4), were identified in tomato foliage, all of which may pla y an important role in regulating growth in this species. (C) 1997 Els evier Science Ltd.