Survey of endogenous gibberellins in a barley mutant showing abnormal response to gravity

Contents of endogenous gibberellins were surveyed in a barley mutant showing abnormal response to gravity in comparison with the original normal line. The contents were assayed by using gibberellin-sensitive dwarf rice strains Tanginbozu and Waito-C. Gibberellin activities were found to be greatly reduced in the mutant line throughout the growth period, and in different plant parts, i, e., leaves, stems and heads. After heading time, gibberellin activities obtained by the Waito-C assay was especially reduced in the mutant line. These results suggest that biosynthesis, especially the ability in the site of 3β-hydroxylation, is greatly reduced in the mutant line.