2,4-表油菜素内酯和生长素促进大麦胚芽鞘伸长生长的协同作用

Synergistic effects of 2,4-epibrassinolide and auxin in promotion of coleoptile elongation in barley

以大麦胚芽鞘为材料,研究了生长素吲哚乙酸(indole-3-acetic ac id,IAA)和2,4表油菜素内酯(2,4-ep ibras-sinolide,ep iBR)对胚芽鞘伸长的影响。结果表明:200μmol.L-1IAA和1μmol.L-1ep iBR在黑暗条件下均促进大麦胚芽鞘的伸长生长,而且在该过程中二者存在协同作用,但必须是在IAA之前施用ep iBR或两者共同处理时才能表现;100 mg.L-12,3,5三碘苯甲酸(2,3,5-triiodobenzoic ac id,TIBA)能抑制ep iBR诱导的胚芽鞘伸长生长,暗示IAA的极性运输是ep iBR促进大麦胚芽鞘伸长生长所必需的;内源激素分析表明,ep iBR处理后胚芽鞘内源IAA含量上升,暗示ep iBR对大麦胚芽鞘伸长的促进作用在一定程度上通过调控内源IAA的水平起作用。

Barley coleoptile segments were used to study the interactions between 2, 4-epibrassinolide （epiBR） and indole-3-acetic acid （IAA） in regulation of elongation process. The results showed that both 200 μmol·L^-1 IAA and 1μmol·L^-1 epiBR promoted coleoptile elongation in dark. They showed a synergistic relationship only when epiBR was applied before IAA or they were treated at the same time. Furthermore, the impact of epiBR on coleoptile elongation could be inhibited by 100 mg· L^-1 2, 3, 5- triiodobenzoic acid （TIBA）, which suggested that the effect of epiBR was partly dependent on the IAA polar transportation. Assay of plant hormones revealed that exogenous epiBR increased IAA content in coleoptile, which suggested that epiBR might also act its function through the increase of IAA level.