EAPSI: Investigating molecular connections between internal and external cues that affect seedling development

关于提高作物生产力的一个关键问题是，植物如何整合外部信号(如光)和内部信号(如激素信号)来改变生长和发育。之前在模式植物拟南芥上的工作发现了几种DNA结合蛋白，它们在抑制幼苗对光的反应中发挥着类似的作用。更多的证据表明，这些蛋白质也可能与植物体内的激素信号通路相互作用。根据这两条信息，这些基因很可能是影响幼苗发育的外部光信号和内部激素途径之间的分子集成点。这一假设将与位于日本横滨的理研可持续资源科学中心的杉本惠子博士合作进行验证。理研在植物激素研究领域享有盛誉，杉本博士和该研究所的其他研究人员拥有专门的尖端技术和专业知识，这将使两种独特但互补的方法被用于研究这一问题。AT-Hook基序核定位(AHL)基因家族是植物特有的，但在植物中普遍存在，调节光培养拟南芥幼苗的下胚轴生长。本研究将使用两种不同的生化技术，研究AHLS是否在光信号和植物激素途径之间作为控制下胚轴生长的遗传整合点。第一个特定目标将使用染色质免疫沉淀和测序(CHIP-SEQ)来测试AHL是否直接与与植物激素信号通路相关的DNA序列结合。在具体目标二，将使用质谱学来评估AHL基因是否影响各种植物激素的内源水平。具体地说，将从不同AHL突变体的幼苗中产生激素谱并进行比较。该NSF EAPSI奖是与日本科学促进会合作资助的。

A key question in regards to improving crop productivity is how plants integrate both external signals, such as light, and internal signals, such as cues from hormones, to alter growth and development. Previous work on the model plant Arabidopsis thaliana identified several DNA-binding proteins which play similar roles in suppressing seedling elongation in response to light. Additional evidence indicates that these proteins may also interact with internal plant hormone signaling pathways. Based on these two pieces of information, it seems likely that these genes serve as molecular integration points between external light signals and internal hormone pathways that influence seedling development. This hypothesis will be tested in collaboration with Dr. Keiko Sugimoto at the RIKEN Center for Sustainable Resource Science in Yokohama, Japan. RIKEN is renowned in the field of plant hormone research, and Dr. Sugimoto and other researchers at the institute possess specialized, cutting-edge technology and expertise which will allow two unique but complementary approaches to be used to investigate this question.The AT-HOOK MOTIF NUCLEAR LOCALIZED (AHL) gene family, specific to and yet ubiquitous in plants, modulates hypocotyl growth in light-grown Arabidopsis seedlings. This research will investigate if the AHLs serve as a genetic integration point between light signaling and phytohormone pathways in the control of hypocotyl growth, by using two different biochemical techniques. The first specific aim will test if AHLs bind directly to DNA sequences associated with plant hormone signaling pathways, using chromatin immunoprecipitation followed by sequencing (ChIP-SEQ). In specific aim two, mass spectrometry will be used to evaluate if AHL genes influence the endogenous levels of various plant hormones. Specifically, hormone profiles will be generated from the seedlings of various AHL mutants and compared. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.