Ritchie Sian, Gilroy Simon
Biology Department, The Pennsylvania State University, 208 Mueller Laboratory, University Park, Pennsylvania 16802, USA.
To whom correspondence should be addressed. E-mail:
New Phytol. 1998 Nov;140(3):363-383. doi: 10.1111/j.1469-8137.1998.00299.x.
The range of processes regulated by gibberellins (GAs) covers all aspects of the life history of the plant from seed germination to vegetative growth and flowering. In seeds there has been an intensive search, using the techniques of both biochemistry and cell biology, for the regulatory molecules linking GA perception to gene regulation and the events of germination. Although a GA receptor has yet to be identified, the site of perception has been localized to the plasma membrane. Calmodulin, Ca and cGMP have also been identified as elements of the GA signal transduction pathway. These regulators parallel many of the signalling elements identified in the transduction of other signals such as phytochrome and ABA. Studies of GA-regulated gene expression, principally of the α-amylases of cereal aleurone, have identified core GA-responsive promoter elements, such as the gibberellin response element (GARE), box-1 and pyrimidine boxes, as well as elements that may lend specificity to GA-regulated expression, such as the Opaque-2-similar element (O2S), and TRE and CRE motifs. One of the most striking features of all of these studies of the molecular basis of GA action is the interaction of GA-dependent regulatory elements with those of other factors such as ABA. GA-response elements also appear to be conserved between disparate GA-response systems. For example, Myb transcription factors appear to regulate a multitude of GA-induced genes in cereal aleurone as well as to alter GA responses when expressed in Arabidopsis. Thus the study of GA signal transduction and response systems is highlighting the conservation of regulatory elements used by plants. These common factors, used by distinct signal transduction systems, provide a molecular basis for the integration of the GA signal with other growth regulators that is the hallmark of plant growth and development. CONTENTS Summary 363 I. Introduction 364 II. Responses of cereal aleurone to GA 364 III. GA and genes 370 IV. Conclusions and perspectives 378 Acknowledgments 379 References 379.
赤霉素（GAs）所调控的一系列生理过程涵盖了植物从种子萌发到营养生长及开花的整个生活史。在种子中，人们运用生物化学和细胞生物学技术，深入探寻将GA感知与基因调控以及萌发事件联系起来的调控分子。尽管尚未鉴定出GA受体，但感知位点已定位到质膜。钙调蛋白、Ca和cGMP也已被确定为GA信号转导途径的组成部分。这些调控因子与在其他信号（如光敏色素和脱落酸）转导过程中鉴定出的许多信号元件相似。对GA调控基因表达的研究，主要是针对谷物糊粉层的α -淀粉酶，已鉴定出核心GA响应启动子元件，如赤霉素响应元件（GARE）、box - 1和嘧啶盒，以及可能赋予GA调控表达特异性的元件，如不透明 - 2类似元件（O2S）、TRE和CRE基序。所有这些关于GA作用分子基础的研究中，最显著的特征之一是GA依赖的调控元件与其他因子（如脱落酸）的调控元件之间的相互作用。GA响应元件在不同的GA响应系统之间似乎也具有保守性。例如，Myb转录因子似乎在谷物糊粉层中调控众多GA诱导的基因，并且在拟南芥中表达时也会改变GA响应。因此，对GA信号转导和响应系统的研究凸显了植物所使用的调控元件的保守性。这些不同信号转导系统所共有的因子，为GA信号与其他生长调节因子的整合提供了分子基础，而这种整合正是植物生长发育的标志。 目录 摘要363 一、引言364 二、谷物糊粉层对GA的响应364 三、GA与基因370 四、结论与展望378 致谢379 参考文献379
