Wheat powdery mildew is one of the diseases that threaten food security. Currently, improving the resistance of wheat to powdery mildew, especially broad-spectrum resistance, is the main task in the field of wheat disease resistance breeding. Wild two grain wheat is the wild ancestor species of common wheat, which has undergone long-term and complex environmental evolution, accumulated rich genetic diversity, and is a valuable resource for modern wheat disease resistance genetic improvement.
Liu Zhiyong, a researcher of the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences, and Zhao Yusheng's team cloned the broad-spectrum powdery mildew resistance gene Pm36 by using map based cloning, PacBio long reading genome re sequencing, mutant and transgenic function verification and other methods. Pm36 encodes a novel transmembrane domain tandem kinase (WTK7-TM) protein. Identification of multiple races of powdery mildew revealed that WTK7-TM exhibited immunity or high resistance to all 104 tested physiological races of powdery mildew in different ecological regions of China. Research has found that there is a significant phenomenon of genome expansion and the production of new genes at the Pm36 locus. EMS mutant experiments have found that the two kinase domains and transmembrane domains of WTK7-TM are crucial for disease resistance. Preliminary in vitro phosphorylation experiments have confirmed that the two kinase domains of the tandem kinase WTK7-TM are necessary for both self phosphorylation and substrate phosphorylation abilities. Evolutionary analysis shows that the two kinase domains may have been generated through repetitive forms and belong to the "serine/threonine" type kinase. Subcellular localization revealed that the tandem kinase WTK7-TM is localized on the cytoplasmic membrane. Genetic tracing analysis revealed that the Pm36 gene is rare and distributed in the southern population of wild two grain wheat, and is not involved in the evolutionary process of wheat, and is missing in the modern wheat gene pool. This study used molecular design breeding to introduce the Pm36 gene into the main wheat varieties in China's main production areas, creating a new wheat germplasm ZKPm36 with high yield and disease resistance. This provides genetic resources and lays a theoretical foundation for cultivating new wheat varieties with broad-spectrum resistance to powdery mildew.
On April 10th, the related research findings were published online in Nature Communications, titled A member associated tank kinase from wild emer while conferences broad spectrum resistance to powdery milk. The research work has received support from the National Key R&D Program, National Natural Science Foundation of China, Hebei Province Key R&D Program, and the "Unveiling and Leading" project of the Yazhou Bay Seed Laboratory in Hainan Province.
Paper link
Cloning of the Pm36 locus of the wheat broad-spectrum resistance gene to powdery mildew
