STUDY ON ACTION MECHANISM OF BRASSINOSTEROIDS

1)油菜素内酯(testerone-gt；tyhasterol-&gt；cststerone-&gt；brassinolide)的生物合成途径存在于细胞培养物和完整的植物组织中。3)在多年生黑麦草花粉中发现3-脱氢睾酮是茶酮和类固醇的中间产物。2)免疫细胞化学检测到油菜素类固醇分布在淀粉体中。3)从百合花粉中鉴定出茶甾酮的肉豆蔻酸酯。4)蓝光照射引起水稻叶片展开，提高了油菜素类固醇的生物活性。然而，这并不是由于内源油菜素内酯含量增加所致。从真菌德氏麦长管菌中分离得到一种名为KM-01的抗油菜素内酯，并对其化学结构进行了测定。合成了缓释型合成油菜素内酯，并筛选出一种可用于实际农业的候选化合物。7)分析了油菜素内酯对Striga和Orobanche种子萌发的调节作用。8)与生长素不同，油菜素内酯的生长效应与微管行为和茎组织内层有关。9)油菜素内酯的耐冷性是基于其对植物细胞膜的稳定作用。

1)A biosynthetic pathway of brassinolide (teasterone -> typhasterol -> cstasterone -> brassinolide) is found in both cell cultures and intact plant tissue. 3-Dehydrotesterone was found as an intermediate between teasterone and typhasterol2)In pollen of Lolium perenne, brassinosteroid is distributed in amyloplast as examined by immunocytochemistry.3)A myristate ester of teasterone was identified from lily pollen.4)Biological activity of brassinosteroids in rice leaf was increased by irradiation of blue light which causes unrolling of the rice leaf. However, this is not due to increased level of endogenous brassinosteroids.An antibrassinolide termed KM-01 was isolated from a fungus Drechslera avenae and the chemical structure was determined.Slow-releasing synthetic brassinolides were synthesized and a candidate was seltected for practical agricultural use.7)Conditioning effects of brassinolide on seed germination of Striga and Orobanche were analyzed.8)In contrast to auxin, growth effect of brassinosteroids is related with microtuble behavior and with inner layr of stem tissue.9)Cold tolerance effects of brassinosteroids are based on their stabilizing effects of plant membrane.