Effect of Gibberellin Biosynthesis Inhibitor Ancymidol on Growth, Floral Initiation and Endogenous GA levels in Sorghum bicolor

수수의 생육과 개화 및 내생 GA 함량에 미치는 지벨렐린 생합성억제제 Ancymidol의 영향

This study was conducted to correlate changes in plant growth and flowering behavior with inhibition of gibberellin synthesis following application of GA biosynthesis inhibitor. Two sorghum genotypes, wild-type and phyB-1(phytochrome B mutant) which grow fast and flowers early relative to the wild-type, were used. Both growth and floral initiation of these two genotypes were greatly affected by ancymidol concentration increased. However, these growth inhibition and delayed flowering are almost completely overcome by simultaneous applications of 31.6ppm $GA_3$. The ability of $GA_3$ to reverse the effect of the inhibition on both growth and floral initiation in sorghum suggests a role for native GAs in sorghum flowering. This result was contrast to the fact that in some long day plants GA biosynthesis inhibitors will inhibit shoot elongation but not floral initiation. In sorghum, inhibition of vegetative growth by GA biosynthesis inhibitor is accompanied by a delay in flowering. Ten ppm of ancymidol treatments drastically reduced all early-13-hydroxylation pathway GAs($GA_{12}$, $GA_{53}$, $GA_{19}$, $GA_{20}$, $GA_3$, and $GA_8$) levels.

단일식물인 수수의 개화에 지베렐린이 관여하는지를 조사하기 위하여 지베렐린 생합성 억제제인 ancymidol을 처리한후 내생 지베렐린의 함량과 개화 및 생육에 미치는 영향을 조사한 결과는 다음과 같다. 1. 지베렐린 생합성 억제제 ancymidol은 공시한 두 품종 모두의 생육을 억제함과 동시에 개화를 지연시켰다. 2. $GA_3$를 Ancymidol과 동시에 처리할 경우 생육억제와 개화지연이 모두 회복되어 지베렐린이 수수의 개화에 관여함을 보였다. 3. Ancymidol 10ppm은 수수의 모든 지베렐린 ($GA_{12}$, $GA_{53}$, $GA_{44}$, $GA_{19}$, $GA_{20}$, $GA_1$ 합성을 현저히 억제하였다.