特殊细胞壁结构调控质外体与共质体离子运输途径的分子基础和作用机制

质外体和共质体途径是植物矿质元素运输的两个主要理论途径，但长期以来仅有生理学和解剖学的依据，而在分子遗传层面上缺乏证据支持。内皮层凯氏带和木栓质片层以及胞间连丝分别是控制矿质元素运输质外体途径与共质体途径的重要特殊细胞壁结构，然而不仅它们形成的分子基础存在着很多未知，而且人们对于它们之间的关系以及它们调控植物矿质元素的具体机制更是知之甚少。我们在前期研究中不仅综合利用利用离子组学、遗传学和反向遗传学鉴定了一系列的凯氏带、木栓质片层以及胞间连丝形成的突变体，并同时发现了一系列新的科学问题和深入阐明质外体途径和共质体运输的新切入点。因此，本项目拟在前期研究的基础上，综合利用分子生物学、细胞生物学、遗传学以及生理生化的研究，揭示调控植物矿质元素运输通路的特殊细胞壁结构凯氏带和木栓质片层以及胞间连丝形成的分子基础，以及它们调控矿质元素平衡的作用机制。

Apoplastic and symplatic pathways are two hypothesized pathways for mineral nutrient transportation. This old hypothesis mainly relies on evidences from physiological and anatomical studies, but lacks of molecular and genetic support. Endodermic Casparian strip and suberin lamella and plasmodesmata are special cell wall structures that regulate apoplastic and symplatic pathways, respecitively. However, not only the molecular basis underlying their formation remains largely unknown, the relationship between the three special structures and how they regulate ion homeostasis are also elusive. In our prophase research, we identified a series of mutants with defects in formation of Casparian strip, suberin lamella and plasmodesmata by a combined strategy of ionomics, forward genetics and reverse genetics, and also discovered a series of new scientic questions and new cut-in points to for deeply understanding apoplastic and symplastic pathways. Here we propose to uncover the molecular basis underlying the formation of these special cell wall structures and the mechanisms of them in regulation of ion homeostasis, through a series studies of molecular biology, cell biology, genetics, biochemystry and plant physiology.