摘要
油菜甾醇内酯类化合物对叶片展开(leaf-unrolling)的生物活性,以表油菜素内酯效应为最强。epiBR的作用与其浓度及苗龄有关,0.0001ppm时已表现促进作用,至1ppm达最高;epi-BR对4d龄叶片促进最明显,随苗龄增加逐渐下降,表明幼嫩叶片比老叶片对epiBR更为敏感。epiBR能克服环己酰亚胺和放线菌素D对叶片展开的抑制;epiBR与脱落酸之间亦存在拮抗,而与6BA则表现加成作用。
Effects of epiBR on leaf-unrolling were studied with etiolated leaf segments of wheat seedlings.
epiBR and its synthetic analogues showed strong activity in promoting wheat leaf-unrolling. We found that the effect of epiBR was the greatest among the 4 brassinosteroids tested. The extent of leaf-unrolling depended on the concentration of epiBR, durafion of pretreatment and age of wheat seedlings. ABA strongly reduced the promoting effect of epiBP on leafunrolling, while IAA showed weak inhibitory activity. Effects of epiBR on the unrolling of leaf segments were partly nullified by actinomycin D and cycloheximide.
Effects of epiBR and 6BA in these test systems were additive. However, the lag period (4～5h) of epiBR effect was longer than that of 6BA. It is suggested that the promotion of leafunrolling by epiBR and 6BA may be regulated in different modes.
基金
国家自然科学基金
关键词
小麦
表油菜素内酯
叶片展开
epibrassinolide (epiBR)
6BA
leafunrolling
endogenous gibbrellin
