Transcriptional regulation of aluminum and phosphate stres-responsive genes in plants

酸性土壤是全世界农业生产的主要限制因素。限制植物在这些土壤上生长的因素包括铝(Al)毒性和磷(PI)缺乏。因此，植物对酸性土壤的适应需要增强对铝的耐受性的机制和促进磷的获得的机制。基因表达实验的初步分析(拟南芥中Al胁迫的转录组图谱和油菜中PI胁迫的转录组图谱)已经确定了一系列对这两种胁迫(共同表达，潜在共同调节)做出响应的基因。一个引人注目的观察结果是，铝和磷胁迫都导致了与碳代谢(糖酵解)有关的许多酶的编码基因表达的变化。一个耐人寻味的可能性是，通过糖酵解增加碳流不仅是为了提供胁迫特定的代谢物，不仅是为了抵抗铝和磷胁迫，也是为了其他需要大量碳资源分配的非生物胁迫。为了深入了解植物对铝和磷胁迫的反应，我们必须识别和描述参与这些胁迫反应的调控网络(S)。本研究的目的是利用现有的遗传、分子和计算工具来确定拟南芥A1和PI逆境反应系统(S)的调控成分，并深入了解这些途径的调控及其共有的关系。为了确定调控网络的组成部分(S)，我们将使用两种互补的技术来检测DNA结合蛋白(例如转录因子)和它们结合的DNA序列(例如顺式调控元件)之间的相互作用。从这项研究中获得的知识将有助于我们实现开发能够更好地耐受酸性土壤的作物品种的长期目标。

Acid soils are a major limitation to agricultural production worldwide. Factors that limit plant growth on these soils include aluminum (Al) toxicity and phosphate (Pi) deficiency. As a result, plant adaptation to acid soils requires mechanisms that confer tolerance to Al and mechanisms to enhance Pi acquisition. Preliminary analysis of gene expression experiments (transcriptome profiling of Al stress in Arabidopsis and Pi stress in canola) has identified an array of genes responsive to both stresses (co-expressed, potentially co-regulated). One striking observation was that both Al and Pi stress induced changes in expression of genes coding for many enzymes involved in carbon metabolism (glycolysis). An intriguing possibility is that increases in carbon flow through glycolysis are required to supply stress-specific metabolites not only for resistance to Al and Pi stress, but also for other abiotic stresses requiring a large allocation of carbon resources. To gain insight into plant responses to Al and Pi stress, we must identify and characterise the regulatory network(s) involved in these stress responses. The goal of the proposed research is to use current genetic, molecular, and computational tools to identify regulatory components of the Al and Pi stress response system(s) in Arabidopsis, and provide insight into the regulation of these pathways and the relationships they share. To identify components of the regulatory network(s), we will use two complementary techniques that detect interactions between DNA-binding proteins (e.g. transcription factors) and the DNA sequences to which they bind (e.g. cis-regulatory elements). The knowledge gained from this research will aid our long term goal of developing crop species better able to tolerate acid soils.