Photocontrol of bud burst involves gibberellin biosynthesis in Rosa sp.
Photocontrol of bud burst involves gibberellin biosynthesis in Rosa sp.
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DOI：
10.1016/j.jplph.2012.04.014
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发表时间：
2012-09-01
影响因子：
4.3
通讯作者：
Sakr, Soulaiman
中科院分区：
文献类型：
--
作者：
Choubane, Djillali;Rabot, Amelie;Sakr, Soulaiman
在许多物种中，光通过控制分枝模式和芽的萌发，是植物形状的关键决定因素。为了深入了解光是如何诱导月季萌发的，我们研究了光在月季中的诱导作用是否与赤霉素(GA)的生物合成有关。在砍头植株的腋芽中，两个GA生物合成基因(RoGA20ox和RoGA3ox)的表达被迅速而强烈地诱导，而一个GA分解代谢基因(RoGA2ox)的表达被迅速而强烈地诱导。相反，这两个GA生物合成基因在黑暗中的表达水平较低，并与芽萌发的完全抑制有关。这种效果依赖于光的强度和质量。在体外培养的芽中，GA生物合成的两种效应物--环孢菌素和多效唑抑制了光对预成叶生长和SAM器官发生活性的诱导作用。这种效应是浓度依赖性的，并被GA(3)所抵消。然而，单独使用GA(3)并不能挽救黑暗中萌发的芽。GA的生物合成也是液泡转化酶的表达和活性所必需的，因此也是光诱导芽内糖代谢所必需的。这些发现证明了GA的生物合成有助于光对芽萌发的影响，并为更好地了解GA在植物分枝中的确切作用奠定了基础。(C)2012年爱思唯尔股份有限公司。版权所有。
Light is a critical determinant of plant shape by controlling branching patterns and bud burst in many species. To gain insight into how light induces bud burst, we investigated whether its inductive effect in rose was related to gibberellin (GA) biosynthesis. In axillary buds of beheaded plants subject to light, the expression of two GA biosynthesis genes (RoGA20ox and RoGA3ox) was promptly and strongly induced, while that of a GA-catabolism genes (RoGA2ox) was reduced. By contrast, lower expression levels of these two GA biosynthesis genes were found in darkness, and correlated with a total inhibition of bud burst. This effect was dependent on both light intensity and quality. In in vitro cultured buds, the inductive effect of light on the growth of preformed leaves and SAM organogenic activity was inhibited by ancymidol and paclobutrazol, two effectors of GA biosynthesis. This effect was concentration-dependent, and negated by GA(3). However, GA(3) alone could not rescue bud burst in the dark. GA biosynthesis was also required for the expression and activity of a vacuolar invertase, and therefore for light-induced sugar metabolism within buds. These findings are evidence that GA biosynthesis contributes to the light effect on bud burst and lay the foundations of a better understanding of its exact role in plant branching. (c) 2012 Elsevier GmbH. All rights reserved.