25. Curing Crown Gall
Stephen C. Winans, Microbiology, discovered how a wound in plants like grapevines develops into a tumor. A soil bacterium, Agrobacterium tumefaciens, enters the wound, where it copies the genes required for infection, which can enter the plants’ cells and their nuclear DNA causing a cancer-like disease, crown gall. The cells of the crown gall tumor synthesize compounds called opines, which serve as food for the bacterial invaders. Crown gall attacks plants such as cherry and peach trees, raspberries, and chardonnay and cabernet sauvignon grapes. The disease stunts the growth or kills the plant, and there are no controls for it. The discovery leads the way for a cure. The finding could also be used for more effective delivery of DNA for biotechnology applications, since mutant forms of Agrobactrium are widely used in agricultural biotechnology for their ability to create transgenic plants containing new genes of scientific or economic interest.