The death stops here

Plants rely on a sensitive process of programmed cell death to curtail pathogenic infection by selectively executing infected cells. To prevent the death response from spreading to noninfected areas, cells near and at the site of infection activate autophagy, say Yule Liu, S. Dinesh-Kumar (Yale University, New Haven, CT), and colleagues. In virus-infected plants that are unable to turn on autophagy, cell death spreads from the site of infection to surrounding healthy tissues and even to adjacent leaves.

“The programmed cell death response is very discrete, and we were interested in answering the question of what makes death stop,” says Dinesh-Kumar. To that end, the team used RNAi to identify genes involved in disease resistance and the programmed cell death response. They struck death paydirt when they silenced BECLIN1...