Crop diseases are a critical limiting factor for agricultural production and a serious threat to food security in China. Disease resistance proteins are the most prominent family of immune receptors in plants. They sense the invasion of pathogenic bacteria and fungi and trigger the immune response and disease resistance process. The study of the molecular mechanisms of how disease-resistant proteins trigger plant immunity and lead to disease resistance has been a major scientific question in the plant field.
Previously, a collaborative study revealed that the ZAR1 resistosome formed a Ca2+-permeable channel for triggering immune signals. However, it remains elusive whether the plant resistosome share a common mechanism for triggering plant immunity.
A joint team led by Dr. CHAI Jijie from Tsinghua University/University of Cologne, Paul Schulze-Lefert from the Max Planck Institute for Plant Breeding Research, and CHEN Yuhang from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences (CAS), have recently elucidated the molecular mechanisms of Sr35 resistosome using multidisciplinary approaches of structural biology, plant genetics, and electrophysiology.
Results were published in Nature
on Sept. 26.
In this study, the researchers revealed for the first time that the wheat disease resistance receptor protein Sr35 can be recognized and activated by AvrSr35, the effector of wheat stem rust pathogen Puccinia graminis f sp. tritici (Pgt), and further oligomerized to form Sr35 resistosome.
They found that the wheat Sr35 resistosome assembles into a Ca2+-permeable pentameric cation channel, similar to the ZAR1 resistosome. These findings suggest that the plant immune receptor channels share a conserved common mechanism to trigger the immune response and disease-resistant processes.
This work lays a foundation for the cross-species modification and utilization of CNL-like disease resistance proteins. This research has promising applications in agricultural production.
The researchers also precisely modified non-functional homologous proteins of disease susceptible crops to obtain disease resistance functions based on structural studies, providing a new strategy for designing disease-resistant crops.
The research was supported by the Strategic Priority Program of CAS and the National Key R&D Program of China.