Plants Sacrifice Cells to Survive

In a similar way to burning crops in front of an invading army, plants will kill off cells (shown above in brown) around an area infected by a pathogen (shown in purple).  Researchers recently discovered a gene that limits this so-called programmed cell death (PCD).

A biological process in both plants and animals, PCD occurs not only as an immune response, but also in embryonic development and the elimination of defective cells.  In certain plants, PCD is used to create a protective zone of dead cells that isolates an invaded site from the rest of the plant.

Savithramma Dinesh-Kumar from Yale University and his colleagues isolated a gene in tobacoo plants that normally propagates a "stay alive" signal in plant tissue.  When that input was removed, the PCD signal from an infected area moves out and damages the rest of the plant.

The discovery could help understand those instances where PCD malfunctions, such as cancer, Alzheimer's and AIDS.

The scientists describe their work, which was supported by the National Science Foundation, in the May 20 issue of the journal Cell.

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-- Michael Schirber

Credit: Nicolle Rager Fuller, National Science Foundation