Chinese scientists have discovered a possible “death switch” mechanism in plant’s immune system that triggers infected cells to self-destruct, thus limiting the spread of the disease and keeping other parts of the plant healthy. This is as per the findings published in the journal ‘Science’. Scientists said the discovery provides clues to cell death control and immunity for plants, and they hope further research can lead to a new generation of disease-resistant crops that use significantly less pesticide and are more environmentally friendly.
The research was done by scientists from Tsinghua University and the Chinese Academy of Sciences’ Institute of Genetics and Development Biology. About 20 years ago, scientists discovered that plants, like animals, have robust immune systems that can protect them from pathogens including viruses, fungi, bacteria and parasites. Plants also have a unique “lure and catch” immune response to deal with pathogens that have breached their cellular defence, but exactly how this worked remained unknown.
To probe this mystery, Zhou Jianmin, a researcher and his team investigated a protein called AvrAC, which is produced by a bacterial pathogen that causes black rot on cabbage. The bacterium injects AvrAC into plant cells, where it acts as a “biochemical weapon” weakening the plant’s immune system.
In addition to discovering this defence mechanism, Zhou and his associates from the Tsinghua University created structural models of the resistosome from their research. This allows other scientists to examine its composition and functions more closely. The ‘death switch’ is usually harmless to the plant because it only affects diseased cells, which are a tiny portion of the entire plant.