Using natural variation for the investigation of the phytochrome A sequence/function relationship

植物使用不同种类的光感受器来测量周围环境的不同方面。通过将光谱转换为可转导的信号，这些受体控制核基因的表达，以改变生长，以响应不同的刺激，如光谱组成和光强度。光敏色素A是植物中唯一的远红光受体，对植物在荫蔽下的萌发和成苗起着至关重要的作用。在拟议的项目中，我们的目标是找到氨基酸多态性，这些多态性改变了植物对远红光的反应能力，并描述它们如何影响光敏色素a作为蛋白质支架的能力，在该蛋白质支架上整合了多种光依赖性途径。为此，我们将筛选1001基因组计划中的1135份拟南芥材料，找出对远红光响应能力受损的材料，并查明光敏色素A初级序列的特征变化。然后测试这些氨基酸取代对涉及光敏色素A的蛋白质-蛋白质相互作用的影响，并从对远红光响应改变的材料中表征不同光敏色素A变体的特性。该项目的目标将是建立一组重要的氨基酸取代，并将它们与蛋白质-蛋白质相互作用以及它们影响的光敏色素a的其他关键特性联系起来。

Plants use various classes of photoreceptors to measure diverse aspects of their ambient environment. By converting light spectra into transducible signals, these receptors control nuclear gene expression to modify growth in response to diverse stimuli such as spectral composition and light intensity. Phytochrome A is the only far-red light receptor in plants and plays a critical role for germination and seedling establishment in deep canopy shade. In the proposed project, we aim to find amino acid polymorphisms which alter a plant’s capacity to respond to far-red light and describe how they affect the ability of phytochrome A to function as a protein scaffold upon which diverse light dependent pathways are integrated. To this end, we will screen the 1135 Arabidopsis accessions of the 1001 Genomes Project for accessions that are compromised in their ability to respond to far-red light and pinpoint characteristic changes in the primary sequences of phytochrome A. We then test the effects these amino acid substitutions have on protein-protein interactions involving phytochrome A and characterise the properties of the different phytochrome A variants from accessions with altered response to far-red light. The goal of the project will be to establish a set of important amino acid substitutions and link them to the protein-protein interactions and other critical properties of phytochrome A which they influence.