Defining functional components of the plasmodesmal proteome

点击翻译按钮获取中文摘要

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.