Abstract
The gravity response mutant, the weeping type of Japanese cherry, Prunus spachiana, were unable to support their own weight and elongated to downward, since supporting tissue, tension wood were not formed in the branches. But the exogenous gibberellic asid(GA) promoted formation of the tension wood and changed the direction of branches during their growth. In this study the expressions of GA biosynthetic gene in both of the upright and the weeping types of Japanese flowering cherry were investigated. A part of the GA 3β hydroxylase gene (3ox), which synthesizes active GAs, were amplified by real-time RT-PCR technique. The accumulation of 3ox mRNA in the weeping type were much more than that in the upright type. While the endogenous GA1 level was localized and much higher in elongating zone of the weeping type.
