ANALYSIS OF GIBBERELLINS IN A TOMATO (LYCOPERSICON ESCULENTUM) MUTANT WITH SHORT INTERNODE INDUCED BY SEED RADIATION WITH CARBON ION BEAM

摘要

Analysis of gibberellins (GAs) was conducted in a tomato mutant with short internode induced by radiation with carbon ion beam to seeds 'First'. Stem length of the mutant was 60% shorter than that of wild type 'First', while there was little difference in leaf length between these two plants. Stem elongation of the mutant was severely inhibited especially in the internodes above the first true leaf. C-13-hydroxylated GAs (GA_(19), GA_(20), GA_(29), GA_(44), GA_(53) and GA_(97)) and C-13-non-hydroxylated GAs (GA_9, GA_(12), and GA_(15)) were identified in stems of the mutant by GC-MS. Stems of 'First' contained the same classes of GAs. Only C-13-hydroxylated GAs including GAi were identified in leaves of the mutant and 'First'. There was little difference in GA-like activity in either stems or leaves estimated by the dwarf rice micro-drop assay between these two plants. As a result of quantitative analysis by GC-MS, the concentration of GAs in stems and leaves of the mutant tended to be higher thanthat of 'First'. These results suggest that the mutant has the ability to produce GAs comparable to 'First'. It is unlikely that internode shortening of the mutant is caused by the malfunction of GA biosynthesis.