Plant Biology

Human bodies defend themselves using a diverse set of immune cells that circulate from one organ to another, responding to everything from cuts to colds to cancer. But plants don’t have this luxury. Because plant cells are immobile, each cell is forced to manage its own immunity on top of its many other responsibilities. How these multitasking cells accomplish it all—detecting threats, responding to them, and warning others—has remained unclear. Research from Professor Joseph Ecker, postdoctoral researcher Tatsuya Nobori, and colleagues reveals that when plant cells encounter a pathogen, they enter a specialized immune state and temporarily become PRimary IMmunE Responder (PRIMER) cells, a new cell population that acts as a hub to initiate the immune response. The researchers also discovered that PRIMER cells are surrounded by another population of cells they call bystander cells, which seem to be important for transmitting the immune response throughout the plant. The findings bring us closer to understanding the plant immune system—an increasingly important task amid the growing threats of antimicrobial resistance and climate change, which both escalate the spread of infectious disease among crops.