Plants are fully sick right now - and not just because indoor plants are in fashion.  They have an immune system, they get infections, and can catch viruses... they just can't move away from their sick neighbours. While we depend on white blood cells to fight off and remember pathogens, plants rely on inherited knowledge of past threats in their DNA, plus the effective altruism of individual cells to sacrifice themselves rather than damage the whole.  Featuring: Associate Professor Andrew Geering, University of Queensland. Professor John Rathjen, Australian National University.  Dr Amy MacKenzie, University of Adelaide. Belinda Smith, ABC Science reporter. Production: Ann Jones, Presenter / Producer. Petria Ladgrove, Producer. Additional mastering:  Emrys Cronin This episode of What the Duck?! was produced on the land of the Wadawarrung and Kaurna people.