PHR1家族转录因子调控植物低磷胁迫转录响应模式的系统分析

植物在缺磷条件下生长时，体内大量基因的表达会发生变化，以触发一系列的适应性反应。拟南芥中，PHR1是调控植物对低磷胁迫转录响应最重要的转录因子。除了PHR1，它的同源蛋白PHL1 (PHR1-like1)，PHL2, 及PHL3在调控低磷胁迫转录响应中也发挥着一定的作用。PHR1在调控低磷响应基因表达中的功能，在多种农作物中也已被证实。然而，自PHR1基因发现至今，近二十年过去了，我们对PHR1家族中各个成员究竟是如何各自发挥作用又一起协调来调控基因的表达并不清楚。本项目将通过对拟南芥中这四个PHR基因的单突变体及各种组合的多突变体的生理学表型和转录组学的比较分析，结合转基因技术，来系统地分析PHR1家族蛋白调控低磷转录响应的工作模式，并构建出它们调控低磷胁迫转录响应的基因网络。研究结果将为我们深入了解植物对低磷胁迫反应的分子机理提供重要线索，并为未来设计作物新品种提供理论依据。

When grown under phosphate (Pi) deficiency, plants undergo a dramatic change of gene expression to trigger an array of adaptive responses. In Arabidopsis, PHR1 is the most important transcription factor that regulates plant transcriptional responses to Pi deficiency. The other family members of PHR1, PHL1 (PHR1-like1), PHL2, and PHL3, play similar and redundant roles in regulating plant transcriptional responses to Pi deficiency. The functions of PHR genes in regulating Pi transcriptional responses have also been demonstrated in several crops. However, even almost 20 years have passed since the discovery of PHR1, how the different members of the PHR1 family orchestrate plant transcriptional response to Pi deficiency still remain unknow. In this work, we will perform comparative analyses of the Pi responses and transcriptomic changes of the single and various multiple mutants of these four PHR genes. Combined with the transgenic techniques to analyze the in vivo functions of some selected genes, we attempt to reveal the modes of action of these PHR transcription factors, which will ultimately lead us to construct a regulatory gene network which controls the plant transcriptional responses to Pi deficiency. The results obtained from this work will provide important clues to better understand the molecular mechanism of plant responses to Pi deficiency, and provide the basis for future design of the new crops with high P efficiency.