The researchers identified the mechanism of one little-understood domain of plant resistance proteins called a "toll-interleukin-1 receptor," or TIR domain. They showed that during plant immune response, the TIR domain degrades a molecule called NAD+, which is essential for metabolism in all organisms. By cleaving NAD+, the plant self-destructs infected cells while leaving others unharmed.
"For 25 years, we didn't know what TIR domains did in plants. So these results were very interesting in terms of advancing our understanding of how TIR domains actually trigger immunity," said Colorado State University Assistant Professor of Biology Marc Nishimura, who is also the research team leader.
For more details, read the news release in the Colorado State University website.