1 ブラシノライドB環部構造変換体のブラシノステロイド活性

概要

論文の詳細を見る
B-ring modified brassinolides (BLs): iso-BL [(22R,23R,24S)-2α,3α,22,23-tetrahydroxy-24-methyl-6-oxa-B-homo-5α-cholestan-7-one], 6a-deoxo-iso-BL, 6-aza-iso-BL, N-methyl-6-aza-iso-BL, 6-deoxo-BL and seco-BL diol, were assayed by rice lamina inclination (RLI) test and by rescue test of hypocotyl elongation using a brassinosteroid (BR) deficient mutant, Arabidopsis det2, which is tentatively termed as det2 hypocotyl elongation (DHE) test. Most of the compounds exhibited DHE activities higher than those on RLI, and iso-BL and 6-deoxo-BL showed DHE activities comparable to that of BL. These results, along with those of 6a-carbaBL analogs previously reported, show that the recongnition of BR molecules at the receptor involved in RLI is more strict than at the receptor involved in DHE at the B-ring region, and that each receptor perceives BR molecules in different structure manner at least at the B-ring region. In addition, an intriguing activity of 5-epi-6a-carba-B-homoBL was observed. This compound unambiguously inhibited DHE at high concentrations, but markedly enhanced DHE activity of BL by co-application. This result indicates that 5-epi-6a-carba-B-homoBL functions as an efficient accelerator of DHE activity of BL. The same effect was observed in RLI as well.
植物化学調節学会の論文
2001-10-09