Function of AP2/ERF transcription factors in phytochrome signalling

AP2/ERF转录因子在光敏色素信号传导中的功能

• 批准号: 499988350
• 负责人: Professor Dr. Andreas Hiltbrunner
• 金额: --
• 依托单位: Institut für Biologie II
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/499988350?language=en
• 关键词: Function; AP2; ERF; transcription; factors

In order to adapt growth and development to the environment, plants constantly monitor the light conditions in their surrounding using dedicated photoreceptors. Phytochromes are photoreceptors sensitive to the red and far-red range of the light spectrum. Upon sensing light, phytochromes accumulate in the nucleus and regulate the expression of hundreds of genes that control seed germination, seedling establishment, induction of flowering, and many other aspects of growth and development. Seed germination and seed dormancy are important ecological and agronomic traits controlled by light and the phythormones abscisic acid (ABA) and gibberellin (GA). ERF55 and ERF58, two closely related AP2/ERF transcription factors that we identified as novel phytochrome interacting proteins, are expressed in seeds and we found that light-dependent seed germination is enhanced in the erf55 erf58 mutant. Light-activated phytochromes bind ERF55/ERF58 and displace them from promoters of germination-repressing genes such as PIF1, SOM, ABI5, and genes coding for ABA anabolic or GA catabolic enzymes, thereby promoting germination. Based on preliminary data, we hypothesise that ERF55 and ERF58 also play a role in setting the depth of dormancy in response to the light environment perceived by the developing seeds. In the first work package of the proposed project, we aim to test this hypothesis and use DAP-seq to identify target genes of ERF55 and ERF58 with a function in regulation of dormancy. ERF55 and ERF58 belong to subgroup A6 of the AP2/ERF transcription factor family. All members of this subgroup interact with phytochromes but – except for ERF55 and ERF58 – are expressed in seedlings or adult plants and not in seeds. Therefore, in the second work package, we aim to identify the functions of these AP2/ERFs in light signalling in seedlings and adult plants, using CRISPR/Cas9 generated erf higher order mutants and high-throughput screening for potential target genes by DAP-seq. Phytochromes bind to the highly conserved DNA-binding domain of AP2/ERFs, suggesting that binding to – and possibly regulation by – phytochromes may be widespread among AP2/ERFs. Several randomly picked AP2/ERFs from different subgroups indeed interacted with phytochromes. In the third work package, we therefore want to screen the entire AP2/ERF family for members interacting with phytochromes. In summary, we have identified members of the AP2/ERF transcription family as novel interactors of phytochromes. In the proposed project, we want to investigate their function in phytochrome-mediated light responses and elucidate the underlying molecular mechanisms.

为了适应环境的生长和发育，植物使用专用的光感受器不断监测周围的光照条件。光敏色素是对光谱的红色和远红范围敏感的光感受器。并调节数百个基因的表达，这些基因控制种子发芽、幼苗建立、诱导开花以及生长和发育的许多其他方面。种子发芽和种子休眠是受光和光控制的重要生态和农艺性状。植物激素脱落酸 (ABA) 和赤霉素 (GA) 是两种密切相关的 AP2/ERF 转录因子，我们确定它们是相互作用的新型光敏色素蛋白，它们在种子中表达，我们发现光依赖性种子发芽在种子中得到增强。 erf55 erf58 突变体。光激活的光敏色素结合 ERF55/ERF58 并将其从发芽抑制的启动子中取代。基因，如 PIF1、SOM、ABI5 和编码 ABA 合成代谢或 GA 分解代谢酶的基因，从而促进发芽。根据初步数据，我们假设 ERF55 和 ERF58 在响应光的休眠深度方面也发挥着作用。在该项目的第一个工作包中，我们旨在测试这一假设并使用 DAP-seq 来识别具有功能的 ERF55 和 ERF58 的靶基因。 ERF55 和 ERF58 属于 AP2/ERF 转录因子家族的 A6 亚组，该亚组的所有成员均与光敏色素相互作用，但除 ERF55 和 ERF58 外，均在幼苗或成年植物中表达，因此不在种子中表达。 ，在第二个工作包中，我们的目标是使用 CRISPR/Cas9 生成的 erf 来识别这些 AP2/ERF 在幼苗和成年植物的光信号传导中的功能高阶突变体和通过 DAP-seq 对潜在靶基因的高通量筛选与 AP2/ERF 的高度保守的 DNA 结合域结合，表明光敏色素的结合以及可能的调控可能在 AP2/ERF 中广泛存在。来自不同亚组的几个随机挑选的 AP2/ERF 确实与光敏色素相互作用，因此，我们希望筛选整个 AP2/ERF 家族中与光敏色素相互作用的成员。总之，我们已经确定 AP2/ERF 转录家族的成员是光敏色素的新型相互作用子，在拟议的项目中，我们希望研究它们在光敏色素介导的光反应中的功能并阐明潜在的分子机制。