Beijing, June 6 (Reporter Sun Zifa) The reporter learned from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences (Institute of Genetics and Development, Chinese Academy of Sciences) that the collaborative team of Chen Yuhang and Zhou Jianmin of the Institute recently successfully cloned the broad-spectrum anti-rhizomatous gene, elucidated its mechanism of action, and named the gene after Wei Tsing, a famous general of China's Western Han Dynasty (English name WTS).
This important research result paper in the field of plant disease resistance was published online in the internationally renowned academic journal Cell on the evening of June 6, Beijing time. This research not only has a good application prospect in the breeding of cruciferous crops resistant to rhizomatous disease, but more importantly, it has discovered a new calcium ion release channel and its mediated immune mechanism in plants for the first time, and has also become another major theoretical breakthrough made by Chinese scientists in this field after the discovery of plant disease-resistant bodies.
Symptoms of enlarged rape roots affected by rhizomatous disease. Photo courtesy of Yang Hui, associate professor of Sichuan Agricultural University
According to the Institute of Genetic Development of the Chinese Academy of Sciences, rhizomatous disease is the most harmful disease in the agricultural production of cruciferous crops such as rapeseed, in response to the major problem of root swelling disease prevention and control of cruciferous crops, Chen Yuhang and Zhou Jianmin's team comprehensively used genetics, biochemistry, structural biology and physiology to isolate, identify and successfully clone the high anti-rhizomatous gene "Weiqing", and also elucidated its molecular mechanism. The "Weiqing" gene encodes a transmembrane protein that has never been reported, and after being introduced into rape, it not only shows good resistance, but also completely normal growth and development; Rapeseed carrying the "Weiqing" gene showed high resistance to multiple rhizomatous bacteria, including highly pathogenic strains on existing resistant varieties, indicating that "Weiqing" is a broad-spectrum resistance gene, so the "Weiqing" gene has good application value in the molecular breeding of rapeseed against rhizomatous disease.
The collaborative team further found that the "Weiqing" gene formed a new pentameric structure with a transmembrane pore in the middle. Electrophysiology and calcium imaging studies have revealed that it is permeable to calcium ions. When rhizoma is infected, the "Weiqing" gene is specifically expressed in the middle column sheath cells and self-assembles into a calcium channel localized to the endoplasmic reticulum, which activates the downstream immune response process by mediating the release of calcium ions in the endoplasmic reticulum, thereby protecting the root vascular bundle system from pathogenic bacteria. The gene forms a protective barrier around the middle pillar, which is similar to the Qin and Han dynasties in establishing a defensive line in the northern mountains to fight the Xiongnu, so it was named after the famous Western Han general Wei Qing by the team.
The research team pointed out that their latest collaborative research results show that plants can not only activate calcium signaling by forming disease-resistant bodies through traditional immune receptor NLR family proteins, but also use non-NLR family proteins to assemble new ion channels to mediate calcium signaling and immune response. Unlike plasma membrane-localized disease-resistant bodies (such as ZAR1 and SR35), the "Weiqing" ion channel is localized to the endoplasmic reticulum. This is also the first new calcium ion release channel discovered in plants. In addition, the induction and mode of action of "Weiqing" gene in the root-specific cell layer have important reference significance for the study of the resistance mechanism of other soil-borne diseases.
It is understood that rape and other cruciferous crop rhizomatosis in China every year incidence area of 4800 million to 6000 million mu, rhizomatous bacteria in the soil can survive for 20 years, once the cultivated land is polluted, it will no longer be suitable for planting cruciferous crops. Since the discovery of rhizomatous in Taiwan and Fujian in the 20s of the 20th century, the occurrence area of rhizomatosis in China has been increasing. Especially in recent years, with the continuous development of agricultural mechanization, rhizomatosis has shown a rapid spread trend in China, so mining efficient broad-spectrum anti-rhizomatous disease genes is a great challenge for anti-rhizomatous disease breeding.
Field-grown canola. Photo courtesy of Hu Baocheng, researcher of Anhui Academy of Agricultural Sciences
The team of Zhou Jianmin and Chen Yuhang of the Institute of Genetics and Development of the Chinese Academy of Sciences has accumulated rich experience in the identification of plant disease resistance genes, functional research, structure elucidation and channel activity identification. Previously, through cooperation with Tsinghua University and other related teams, Zhou Jianmin's team discovered plant disease-resistant bodies for the first time in the world in 2019, revealing the core mechanism of plant NLR family disease-resistant proteins activating immunity and solving the problems that have plagued the field of plant immunity for more than 20 years. Subsequently, Zhou Jianmin's team cooperated with Chen Yuhang's team to reveal the ion channel function of the classical disease-resistant body ZAR2021 in 1, and clarified that calcium ions are the initial signal for plants to activate immunity. In 2022, the ion channel activity of wheat's disease-resistant body SR35 was resolved, which further supported the calcium signaling theory of plant immunity. (End)