Mechanism of Plant Cell-To-Cell Communication

University Of Delaware, Newark DE

Investigators

Abstract

This project focuses on how cells communicate directly with each other to survive and develop as multicellular organisms. Plants have evolved a unique system to exchange molecular information between cells by producing specialized intercellular bridges termed plasmodesmata. A significant body of evidence now supports the concept that plasmodesmata establish a unique control system by allowing a special class of proteins, including transcription factors and RNA molecules, to pass through fields of cells. These findings suggest a crucial role that plasmodesmata may play in controlling developmental and physiological processes in plants. However, very little is known as to what molecular players are involved and how they control the exchange of information across cellular boundaries. The overall hypothesis is that the transport of information molecules through plasmodesmata is a highly selective and regulated process involving protein phosphorylation. As the first step toward testing this hypothesis, a protein kinase, plasmodesmal-associated protein kinase (PAPK) has been identified that might function in regulating macromolecular trafficking. The investigators believe that PAPK will serve as a key molecular handle to dissect the mechanisms involved in this process and will pursue the following specific research objectives using a multidisciplinary approach: (1) Determine the sequence element of PAPK that is required for plasmodesmal targeting. (2) Identify proteins that are involved in the targeting of PAPK to plasmodesmata. (3) Assess the role of PAPK in controlling macromolecular trafficking between cells. Broader impacts: The new discoveries resulting from this project could provide an important insight into elucidating cell-to-cell communication mediated by plasmodesmata. This will open the door for the dissection of the mechanisms and players by which the spread of viral infectious materials and exchange of information molecules involved in orchestrating developmental programs are controlled. As plasmodesmal function is essential for both cell-to-cell communication and long-distance signaling in plants, insights provided from this project could lead to development of new agricultural technology. It will also be possible to gain a fundamental insight into how different organisms including humans have independently evolved to meet the same goal of survival as multicellular organisms. The PI's educational goals can be summarized as: (i) training students to become scientists who are capable of crossing multiple disciplines and (ii) increasing the participation of minority students in modern plant biology which applies biological, biochemical, cell biological and genetic technologies. The PI is committed strongly to training both undergraduate and graduate students from underrepresented groups. The PI will co-ordinate with the staff of a university-wide program, the University of Delaware McNair Program, to interest minority students in internships, research, and scientific seminars and to provide mentorship.