The role of Vacuolar Hexose Exporters during Stress Response and Development

植物的亚细胞糖分配在适应发育线索和外部条件的过程中受到强烈的调节。我们已经确定了液泡葡萄糖出口ERD 6-like 6（ERDL 6），这对细胞葡萄糖稳态和种子储备的组成有显着的影响。ERDL 6表达响应于激活液泡葡萄糖池的因子而被诱导，并且在触发液泡中葡萄糖积累的条件下被降低。因此，erdl 6突变体具有升高的液泡葡萄糖水平，并且在胁迫条件下穿过液泡膜的葡萄糖通量受损。在拟议的资助期内，我们将阐明ERDL 6的进一步特征，包括运输活动的模式以及它在应对其他胁迫（渗透/干旱胁迫，抗冻性，光限制）和发育（花粉成熟/萌发，细胞壁组成）期间的作用，就其转录和转录后调控（磷酸化）。此外，我们将解决的作用，其他ERDLs在己糖出口的液泡的erdl突变体的高通量生长表型，分析多个erdl-KO增强损伤液泡葡萄糖分配，以及测试所描述的erdl 6-KO效应的其他ERDLs的互补。tmts和vha 2，3的组合突变体将有助于探索己糖输出蛋白和其他类型的液泡膜转运蛋白的功能网络，这些转运蛋白调节液泡中糖的分配，并决定植物在胁迫反应和发育过程中的表现。

Subcellular sugar partitioning in plants is strongly regulated in adaptation to developmental cues and external conditions. We have identified the vacuolar glucose exporter ERD6-like 6 (ERDL6), which has a significant impact on cellular glucose homeostasis and composition of seed reserves. ERDL6 expression is induced in response to factors that activate vacuolar glucose pools and reduced during conditions that trigger glucose accumulation in the vacuole. Accordingly, erdl6 mutants have elevated vacuolar glucose levels and glucose flux across the tonoplast is impaired under stress conditions. In the proposed funding period we will elucidate further characteristics of ERDL6 including the mode of transport activity as well as its role during response to other stresses (osmotic/drought stress, freezing tolerance, light limitation) and during development (pollen maturation/germination, cell wall composition) with respect to its transcriptional and post-transcriptional regulation (phosphorylation). In addition, we will address the role of other ERDLs in hexose export from the vacuole by high-throughput growth phenotyping of erdl mutants, analysis of multiple erdl-KOs for enhanced impairment of vacuolar glucose partitioning, as well as testing complementation of the described erdl6-KO effects by other ERDLs. Combinatorial mutants with tmts and vha2,3 will help to explore the functional network of hexose exporters and other types of tonoplast transporters, which regulates vacuolar sugar partitioning and determines the plants performance during stress response and development.