Klatschmohn
During pollination, plants enforce self-incompatibility (SI) as an important means to prevent self-fertilization. Research on the corn poppy ("Papaver rhoeas") has revealed that proteins in the pistil on which the pollen lands, interact with pollen and trigger PCD in incompatible (i.e., "self") pollen. The researchers, Steven G. Thomas and Vernonica E. Franklin-Tong, also found that the response involves rapid inhibition of pollen-tube growth, followed by PCD.