Defining functional components of the plasmodesmal proteome

在生物学中，复杂有机体的生长在一定程度上依赖于物质从一个细胞传递到下一个细胞，并受其控制。植物和动物在这方面的运作方式不同，因为在植物中，细胞被由纤维素和其他多糖分子组成的相对刚性的细胞壁包围，使得细胞与细胞的直接接触变得困难。植物通过穿过细胞壁建造专门的隧道来克服这一障碍。这些隧道被称为“plasmodesmata”（唱。'胞间连丝'）。胞间连丝由细胞膜排列，并含有分子可以从细胞质传递到细胞质的非常小的通道。这些通道也被病毒利用，作为病毒在组织中传播的途径。这种分子流动通过胞间连丝的过程是不受控制的，必须依赖于蛋白质复杂排列对特定分子运动的调节。值得注意的是，这些特定的分子控制植物发育的各个方面，以及植物对病原体攻击的防御。尽管这些结构对植物生长发育和防御非常重要，但我们对其结构或调节其工作方式的蛋白质知之甚少。该项目旨在分离胞间连丝，并使用最先进的蛋白质鉴定技术来分析其蛋白质成分。使用不太精细的方法，我们已经确定了一些胞间连丝蛋白。因此，我们还将分析这些和新发现的蛋白质如何有助于胞间连丝功能。我们将通过使用遗传技术来改变这些蛋白质在植物组织中积累的量，并记录这些变化对植物生长和植物防御的影响，并通过直接测量对通过胞间连丝从细胞到细胞移动的可见分子的影响来实现这一目标。这项工作将有助于解决植物生物学中最大的谜团之一，即植物细胞如何使用限制在细胞内环境中的分子进行通信。

In biology, the growth of complex organisms is dependent upon, and controlled to some degree by, substances being able to pass from one cell to the next. Plants and animals operate differently in this respect since, in plants, cells are surrounded by a relatively rigid cell wall composed of cellulose and other polysaccharide molecules making direct cell-to-cell contact difficult. Plants have overcome this hurdle by building specialised tunnels through the cell wall. These tunnels are called 'plasmodesmata' (sing. 'plasmodesma'). Plasmodesmata are lined by cell membrane and contain very small channels through which molecules can pass from cytoplasm to cytoplasm. These channels are also exploited by viruses as the pathway for virus spread through the tissues. This process of molecular flow through plasmodesmata is not uncontrolled and must depend upon regulation of the movement of specific molecules by complex arrangements of proteins. Notably, these specific molecules control aspects of plant development, and plant defence against pathogen attack. Despite the very great importance of these structures for plant growth and development and defence, we have very little knowledge of their structure or of the proteins that regulate the way they work. This project aims to isolate plasmodesmata and to use state-of-the-art protein identification techniques to analyse their protein constituents. Using less refined approaches, we have already identified a few plasmodesmal proteins. We will therefore also analyse how these and newly identified proteins contribute to plasmodesmal function. We will achieve this by using genetic techniques to change the amount of these proteins accumulating in plant tissues and recording the effect these changes have on plant growth and plant defence, and by directly measuring the effect on visible molecules moving through plasmodesmata from cell to cell. This work will contribute to solving one of the great mysteries in plant biology, how plant cells communicate using molecules restricted to the intracellular environment.