Isolation of photocontrolled gibberellin 3beta-hydroxylase in lettuce seeds.

生菜种子中光控赤霉素 3β-羟化酶的分离。

基本信息

批准号：
03640566
负责人：
INOUE Yasunori
金额：
$ 1.15万
依托单位：
Faculty of Science and Technology, Science University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

Gibberellin was mediated in the photoinduction of lettuce seeds germination. Feeding experiments of ^3H-GAs suggested that the final step of active GA synthesis, namely, 3beta-hydroxylation of GA_<20> to GA_1 was activated by light. The purpose of this research was isolate the 3 hydroxylase from lettuce seeds and to determine the change of activity directly.Enzyme activity of the lettuce seeds homogenate was too low to isolate it caused by the existence of plenty amount of phenolic compounds. Besides, the supply of lettuce seeds was shorted. Therefore, we must change the plant materials from lettuce to Phaseolus virgules.One dwarf variety of P. vergules named "Green dash" was selected from several variety on the viewpoint of photoinhibition of hypocotyl growth. Inhibition rate of hypocotyl growth by white light was age independent between 5 to 10 days after sowing. Effect of light was nearly saturated at 0.4Wm^<-2>. Inhibition rate was linear to the logarithm of irradiation period when it was shorter than 12 hr. Application of GA_3 recover the photoinhibited hypocotyl growth to the dark level. However, growth in the dark was little effected by GA_3. On the other hand, application of GA synthesis inhibitor highly suppress only the growth in the dark. These results suggested that the effect of light was visualize in the length of hypocotyl mediated by gibberellin. Growth inhibition obligated by the application of GA synthesis inhibitor was recovered by the application of GA_3. In this time, about 10 times higher concentration of GA_3 was required for the light grown seedling than dark grown one for full recovery. These results suggested that light induced the reduction of GA level in the hypocotyl and reduced the sensitivity of hypocotyl to GAs.

Gibberellin是在生菜种子发芽的照片诱导中介导的。 ^3H-GAS的喂养实验表明，主动GA合成的最后一步，即，Ga__ <20>至GA_1的3beta-羟基化被光激活。这项研究的目的是将3种羟化酶与莴苣种子分离，并直接确定活性的变化。生菜种子的酶活性匀浆太低而无法隔离它是由于存在大量酚类化合物而引起的。此外，供应生菜种子的供应被短路了。因此，我们必须将植物材料从生菜更改为叶状肠杆菌。从几种矮化的p。vergules选择“绿色仪表”的多种多样，以抑制抑制下胚轴生长的观点。播种后5至10天之间，白光抑制下胚轴生长的抑制率是独立的。光的效果在0.4WM^<-2>下几乎饱和。抑制速率短于辐射周期的对数，其短于12小时。 GA_3的应用恢复光抑制的下胚轴生长到黑暗水平。但是，黑暗中的增长很少受到GA_3的影响。另一方面，GA合成抑制剂的应用仅高度抑制黑暗中的生长。这些结果表明，光的作用在吉布雷素介导的下胚轴的长度中可视化。通过应用GA_3恢复了应用GA合成抑制剂所义务的生长抑制作用。此时，光种植的幼苗比深色生长的幼苗需要大约10倍的Ga_3浓度。这些结果表明，光诱导下胚轴中的GA水平降低，并降低了低尾基对气体的敏感性。