There is a good reason why many drugs are derived from plants. Unable to move away from their persecutors, plants fight back with an arsenal of biological compounds whose effects make animals think twice before eating. These substances may be painful, psychotropic or even lethal, but their general effect is one of deterrence.
Diatoms turn against herbivores in an entirely new way.
In the past Miralto's group has shown how diatoms produce substances that kill baby copepods before they even hatch. These substances are believed to work by interfering with the network of proteins within the cell that controls how it divides. Now Miralto's team have been looking at how diatoms and copepods interact in the wild. Back in the laboratory, the researchers isolated three of the substances responsible, from the diatom Thalassiosira rotula . They found that these substances halted embryonic development in copepods and sea urchins, and prevented human carcinoma cells from dividing.