GIBBERELLIN METABOLISM IN MAIZE - THE STEPWISE CONVERSION OF GIBBERELLIN A(12)-ALDEHYDE TO GIBBERELLIN A(20)

摘要

The stepwise metabolism of gibberellin A(12)-aldehyde (GA(12)-aldehyde) to GA(20) is demonstrated from seedling shoots of maize (Zea mays L.). The labeled substrates [C-13,H-3]GA(12)-aldehyde, [C-13,H-3]GA(12), [C-14(4)]GA(53) [C-14(4)/H-2(2)]GA(44), and [C-14(4)/H-2(2)]GA(19) were fed individually to dwarf-5 vegetative shoots. Both [C-13,H-3]GA(12)-aldehyde and [C-13,H-3]GA(12) were also added individually to normal shoots. The labeled metabolites were identified by full-scan gas chromatography-mass spectrometry and Kovats retention indices. GA(12)-aldehyde was metabolized to GA(53)-aldehyde, GA(12), GA(53), GA(44), and GA(19); GA(12) was metabolized to 2 beta-hydroxy-GA(12), GA(53), 2 beta-hydroxyGA(53), GA(44), 2 beta-hydroxyGA(44), and GA(19); GA(53) was metabolized to GA(44), GA(19), GA(20), and GA(1); GA(44) was metabolized to GA(19); and GA(19) was metabolized to GA(20). These results, together with previously published data from this laboratory, document the most completely defined gibberellin pathway for the vegetative tissues of higher plants. [References: 20]