Functional characterization of a calcium-permeable cation channel in plants

为了对抗非生物和生物胁迫，植物中已经进化出控制防御和抗性反应启动的复杂信号网络。了解刺激-反应耦合的核心要素对于有针对性地改良作物至关重要。植物对大多数非生物和生物胁迫因子的非常早期的反应是胞质游离钙（[Ca 2 +]cyt）的升高，其由Ca 2+渗透性离子通道的激活介导。我们对这些通道蛋白的分子身份的知识仍然是非常初步的，这在我们理解植物的信号转导和胁迫反应中提出了一个主要的障碍。先前已经在液泡膜中鉴定了Ca 2+渗透性双孔通道1，并且初步分析表明其参与Ca 2+依赖性过程。该项目旨在阐明该通道在刺激反应中的作用，并分析该通道在产生[Ca 2 +]cyt信号时所需的情况。此外，通道的负反馈调节模式和第二信使分子的激活将通过电生理学和细胞生物学方法的组合进行分析，包括使用水母发光蛋白和黄色骆驼技术的[Ca 2 +]细胞成像。从这些实验中获得的知识将有助于我们理解Ca 2+稳态和信号传导，这可能最终用于设计具有更有效的胁迫反应的作物。

To counter abiotic and biotic stress, intricate signalling networks that govern the initation of defense and resistance responses have evolved in plants. The understanding of the central elements of stimulus-response coupling is vital for a targeted improvement of crops. A very early response of plants to most abiotic and biotic stress factors is an elevation of cytosolic free calcium ([Ca2+]cyt), which is mediated by the activation of Ca2+-permeable ion channels. Our knowledge on the molecular identity of those channel proteins is still very rudimentary, which presents a major obstacle in our understanding of signalling und stress responses in plants. The Ca2+-permeable Two Pore Channel 1 has previously been identified in the vacuolar membrane and initial analyses suggested its involvement in Ca2+-dependent processes. This project aims to elucidate the role of this channel in stimulus responses and to analyse the circumstances under which this channel is required in the generation of [Ca2+]cyt signals. Furthermore, the mode of negative feedback regulation of the channel and its activation by second messenger molecules will be analysed by a combination of electrophysiological and cell biological approaches, including [Ca2+]cyt imaging using aequorin and Yellow Cameleon techniques. The knowledge gained from those experiments will aid in our understanding of Ca2+ homeostasis and signalling, which may eventually be used in the design of crops with more efficient stress responses.