Analysis of molecular mechanisms involved in the evolution of plant morphology

植物形态演化的分子机制分析

基本信息

批准号：
09640736
负责人：
KYOZUKA Junko
金额：
$ 1.54万
依托单位：
NARA INSTITUTE OF SCIENCE AND TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 2000
项目状态：
已结题

项目摘要

The floral morphology of grass species is distinct from typical dicot plants. In order to achieve a better understanding of the molccular basis for this diversion, we isolated RAP1A, RAP1B and RAG, putative rice homologs for the Arabidopsis class A gene APETALA1(AP1) and class C gene AGAMOUS(AG), respectively. Expression patterns of RAP1A.RAG, and OsMADS2, a rice homolog of the class B gene, were analyzed by in situ hybridization. RAP1A mRNA was expressed in the apical region of the floral meristem at an early stage of spikelet development, and then its expression was localized in developing lemma, palea and lodicules. OsMADS2 transcript was first observed in the region where stamen primordia are formed. Soon after, OsMADS2 mRNA appeared in the lodicule primordia as well as stamen primordia and this RNA accumulation pattern persisted till late stages of floral development. The expression of RAG was observed in stamens and pistils of wild type young spikelets. These RNA accumulation pat … More terns are mostly similar to those of Arabidopsis class A, B, C genes supporting the notion that the ABC model may be extended to rice.In order to clarify the evolutionary relationship between grass sterile organs, such as lodicules, the lemma and the palea, and the dicot floral organs, we expressed RAG, a rice (Oryza sativa L.) AGAMOUS(AG) ortholog, in rice plants under the control of an Actin I promoter.As a consequence of the ectopic expression of the RAG, lodicules were homeotically transformed into stamens. In total, the transformation of lodicules to staminoid organs was observed in 18 out of 26 independent transgenic lines. In contrast to the almost complete transformation occurred in lodicules, none of the transgenic plants exhibited any morphological alterations in the palea or the lemma. Our results confirmed the prediction that the lodicule is an equivalent of a dicot petal and that the ABC model can be applied to rice at least for organ specification in lodicules and stamens. On the other hand, the absence of morphological alterations in the palea or the lemma raised the possibility that the simple application of the ABC model to structures outside the lodicules may not be valid. Less

草种的花卉形态与典型的双子植物不同。为了更好地理解这种转移的摩尔科基础，我们分离了Rap1a，Rap1b和抹布，分别针对A apetala1（AP1）和C类C基因agamous（AG）的拟南芥A类基因同源物。通过原位杂交分析了B类基因的水稻同源物Rap1a.rag和Osmads2的表达模式。 Rap1a mRNA在蜘蛛网发育的早期阶段在花生分生组织的顶端区域表达，然后其表达位于发育中的引理，palea和lodicules中。 OSMADS2转录本在形成雄蕊原始的区域首次观察到。不久之后，OSMADS2 mRNA出现在Lodicule Primordia和雄蕊原始中，而这种RNA积累模式一直持续到花卉发育的后期。在野生型年轻小尖峰的雄蕊和雌蕊中观察到抹布的表达。 These RNA accumulation pat … More terns are mostly similar to those of Arabidopsis class A, B, C genes supporting the notion that the ABC model may be extended to rice.In order to clarify the evolutionary relationship between grass sterile organs, such as lodicules, the lemma and the palea, and the dicot floral organs, we expressed RAG, a rice (Oryza sativa L.) AGAMOUS(AG)直系同源物在肌动蛋白I启动子的控制下的水稻植物中。由于抹布的生态表达，lodicales在同码转化为雄蕊。总的来说，在26个独立的转基因线中，有18种观察到了lodical剂向雄蕊器官的转化。与几乎完全完整的转化相反，在洛迪克（Lodicals）中发生了任何转基因植物，均未表现出对Palea或Lemma的形态学改变。我们的结果证实了这样的预测，即术相当于双子花瓣，并且可以将ABC模型至少用于大米，至少用于洛迪克和雄蕊中的器官规格。另一方面，PALEA或LEMMA缺乏形态学改变，这增加了ABC模型在Lodicals之外的结构中的简单应用可能无效的可能性。较少的