Abstract
Apical dominance is believed to be induced by IAA. But there are evidences that IAA inhibits growth of axillary buds through an indirect mechanism, and an involvement of a hormone-like compound produced by roots was suggested. In this context, strigolactones were isolated as the causal compound. In the present study we tried to detect a compound that induce dormancy of axillary buds, in other words, inhibit outgrowth of axillay buds, in potato roots cultured in vitro with IAA. For detection of dormancy-inducing activity, single-node segments of potato shoots cultured in vitro were used, since without any additions axillay dormant buds soon begin to grow. Water-soluble fraction obtained by solvent fractionation showed strong activity. Further purification of the active compound was carried out by chromatographies on charcoal and Sephadex G-10, TLC and HPLC. Finally pure compound could be obtained. The spectrum by FD mass spectrometry revealed that the compound had a molecular ion peak at m/z 435 (M+). The compound was different from strigolactones. Structural elucidation and experiments such as effect of IAA on the amount of the compound are now in progress.
