School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia.
School of Natural Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
Plant Physiol. 2020 Mar;182(3):1375-1386. doi: 10.1104/pp.19.01173. Epub 2020 Jan 21.
Control of flowering time has been a major focus of comparative genetic analyses in plant development. This study reports on a forward genetic approach to define previously uncharacterized components of flowering control pathways in the long-day legume, pea (). We isolated two complementation groups of late-flowering mutants in pea that define two uncharacterized loci, () and , and describe their diverse effects on vegetative and reproductive development. A map-based comparative approach was employed to identify the underlying genes for both loci, revealing that that LATE3 and LATE4 are orthologs of CYCLIN DEPENDENT KINASE8 (CDK8) and CYCLIN C1 (CYCC1), components of the CDK8 kinase module of the Mediator complex, which is a deeply conserved regulator of transcription in eukaryotes. We confirm the genetic and physical interaction of LATE3 and LATE4 and show that they contribute to the transcriptional regulation of key flowering genes, including the induction of the florigen gene and repression of the floral repressor Our results establish the conserved importance of the CDK8 module in plants and provide evidence for the function of CYCLIN C1 orthologs in the promotion of flowering and the maintenance of normal reproductive development.
开花时间的控制一直是植物发育比较遗传学分析的主要焦点。本研究报告了一种正向遗传方法，用于定义长日豆类豌豆中开花控制途径的先前未表征的成分。我们在豌豆中分离出两种晚花突变体的互补群，定义了两个未表征的基因座 () 和 ，并描述了它们对营养和生殖发育的不同影响。采用基于图谱的比较方法鉴定了这两个基因座的潜在基因，结果表明 LATE3 和 LATE4 是细胞周期蛋白依赖性激酶 8 (CDK8) 和细胞周期蛋白 C1 (CYCC1) 的同源物，它们是 Mediator 复合物 CDK8 激酶模块的组成部分，该复合物是真核生物转录的高度保守调节剂。我们证实了 LATE3 和 LATE4 的遗传和物理相互作用，并表明它们参与了关键开花基因的转录调控，包括诱导开花基因 和抑制花抑制因子 。我们的研究结果确立了 CDK8 模块在植物中的保守重要性，并为 CYCLIN C1 同源物在促进开花和维持正常生殖发育中的功能提供了证据。
