Gibberellin regulates Arabidopsis seed germination via RGL2, a GAI/RGA-like gene whose expression is up-regulated following imbibition
Gibberellin regulates Arabidopsis seed germination via RGL2, a GAI/RGA-like gene whose expression is up-regulated following imbibition
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DOI：
10.1101/gad.969002
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发表时间：
2002-03-01
影响因子：
10.5
通讯作者：
Peng, JR
中科院分区：
文献类型：
--
作者：
Lee, SC;Cheng, H;Peng, JR
赤霉素（GA）促进拟南芥种子的发芽。拟南芥 GAI 和 RGA 是编码关键 GA 信号转导成分（GAI 和 RGA）的基因，介导 GA 对茎伸长的调节。拟南芥基因组还包含两个基因：RGL1 和 RGL2，它们编码与 GAI 和 RGA 密切相关的蛋白质（RGL1 和 RGL2）。在这里，我们发现 RGL2 响应 GA 调节种子萌发，而 RGL1、GAI 和 RGA 则不然。此外，我们发现 RGL2 转录物水平在种子吸胀后迅速上升，然后随着发芽的进行而迅速下降。原位 GUS 染色显示，吸液种子中的 RGL2 表达仅限于出芽前和最近出现的胚根的伸长区域。这些观察结果表明，RGL2 是 GA 反应的负调节因子，专门用于控制种子发芽而不是茎伸长。此外，由于 RGL2 表达是吸胀诱导型，因此 RGL2 可能作为环境和内源信号的整合者来控制种子萌发。
The germination of Arabidopsis seeds is promoted by gibberellin (GA). Arabidopsis GAI, and RGA are genes encoding key GA signal-transduction components (GAI and RGA) that mediate GA regulation of stem elongation. The Arabidopsis genome contains two further genes, RGL1 and RGL2, that encode proteins (RGL1 and RGL2) that are closely related to GAI and RGA. Here, we show that RGL2 regulates seed germination in response to GA, and that RGL1, GAI, and RGA do not. In addition, we show that RGL2 transcript levels rise rapidly following seed imbibition, and then decline rapidly as germination proceeds. In situ GUS staining revealed that RGL2 expression in imbibed seeds is restricted to elongating regions of pre-emergent and recently emerged radicles. These observations indicate that RGL2 is a negative regulator of GA responses that acts specifically to control seed germination rather than stem elongation. Furthermore, as RGL2 expression is imbibition inducible, RGL2 may function as an integrator of environmental and endogenous cues to control seed germination.