Traffic lights signal to cars and buses when to stop, slow and go. Like traffic lights, plant cells send signals to each other to perform photosynthesis to grow or fight off destructive viruses and pathogens.
Plant cells produce plasmodesmata, tiny tubes that act as communication channels, allowing those signals to move from cell to cell. The plasmodesmata will open and close in response to various signals that activate protein regulators such as PDLP5.
“We knew that this protein is critical for plant defense,” said Jung-Youn Lee, a University of Delaware professor of plant molecular and cellular biology and the interim director of the Delaware Biotechnology Institute. “But how does this protein get to the plasmodesmata?”
The question — how these protein regulators find their destination to fulfill their purpose and help a cell function — had been plaguing scientists. Until the University of Delaware got involved.
In new research that made the cover of the journal The Plant Cell, UD researchers found that the protein — PDLP5 — that helps guard plants from the invasion of viruses and bacteria has not one, but two special targeting signals, or “zip codes'' as Lee calls them, unexpectedly stationed outside of cells.