Regulation mechanism by blue light of photomorophogenesis and brassinosteroid activity

本文研究了蓝光对水稻黄化苗叶片倾斜度的光调节机理及粘细菌子实体的形成。用极低浓度的油菜素内酯（BS）处理水稻黄化苗，并用蓝光照射，可显著促进叶片倾斜。在蓝光照射下生长的幼苗叶片倾斜活性比在黑暗下生长的幼苗提高约30倍。在照射3小时内观察到蓝光效应，并且在照射48小时后保持相同的效应。然而，内源水平的BS被鉴定为茶甾酮，typhasterol，castasterone和油菜素。倾斜活动的增强是由于存在一个BS反射。通过HPLC纯化恢复在黑暗下生长的幼苗的倾斜活性，导致存在某种抑制剂， 关于我们 抑制暗生长幼苗中BS-l的功能。事实表明，蓝光效应是起分解或消除BS抑制剂的作用。由于含量很小且不稳定，BS的抑制剂和抑制剂均未能鉴定。但在筛选某些合成化合物时，发现了一个错误。另一方面，在革兰氏阴性菌中，蓝光对粘细菌的生活史中子实体的形成是必不可少的。类胡萝卜素生物合成抑制剂在蓝光照射下抑制子实体的形成。蓝光的作用是在出菇初期使类胡萝卜素积累发生质的变化。类胡萝卜素广泛存在于植物组织中，被认为是蓝光的一种可能受体。确定粘球菌子实体形成的诱导因子将为植物光形态建成提供重要信息。少

This is study on photoregulation mechanism by blue light of lamina inclination of etiolated rice seedlings and formation of fruiting body of Myxobacteria. Lamina inclination of etiolated rice seedlings was remarkably promoted by treatment with brassinosteroid (BS), the six-type of phytohormone, at a extremely low concentration and by irradiation with blue light. A lamina inclination activity in the seedlings grown under blue light irradiation was enhanced about 30 times higher than that grown under the darkness. The blue light effect was observed within 3 hr of irradiation and the same effect was maintained after 48 hr irradiation. However, the endogenous levels of BSs which were identified to be teasterone, typhasterol, castasterone and brassinolide. Enhancement of the inclination activity was caused by presence of a BS synergist. The inclination activity of seedlings grown under the darkness was recovered by means of HPLC purification, resulting presence of a certain suppressor that … More inhibits the function of BS synergist in the dark-grown seedlings. From the facts it was shown that the blue light effect is to play a role of decomposing or removing the suppressor of the BS synergist. Both of the BS synergist and its suppressor failed to identify because of a quite small amounts and unstable compound. But we found a BS synergist during screening some synthetic compounds. Probably it will offer any chemical informations for identification of the natural compound.On the other hand, blue light is essential for formation of fruiting body in a life cycle of Myxobacteria which is most evolutionary in gram negative bacteria. An inhibitor of carotenoid biosynthesis inhibited forming the fruiting body under blue light irradiation. Effect of blue light was to changing qualitatively in carotenoid accumulation at the beginning of the fruiting formation. Carotenoid commonly distributed in plant tissues has been counted to be one of a possible receptor of blue light. Assignment of a factor inducing the fruiting body formation of Myxococcus will offer very useful information as to photomorphogenesis of plants. Less