a rice gene of de novo origin negatively regulates pathogen-induced defense response新创的水稻基因起源负调节pathogen-induced防御反应.pdfVIP

A Rice Gene of De Novo Origin Negatively Regulates Pathogen-Induced Defense Response 1 1 1 1 1 2 1 Wenfei Xiao , Hongbo Liu , Yu Li , Xianghua Li , Caiguo Xu , Manyuan Long , Shiping Wang * 1 National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China, 2 Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America Abstract How defense genes originated with the evolution of their specific pathogen-responsive traits remains an important problem. It is generally known that a form of duplication can generate new genes, suggesting that a new gene usually evolves from an ancestral gene. However, we show that a new defense gene in plants may evolve by de novo origination, resulting in sophisticated disease-resistant functions in rice. Analyses of gene evolution showed that this new gene, OsDR10, had homologs only in the closest relative, Leersia genus, but not other subfamilies of the grass family; therefore, it is a rice tribe-specific gene that may have originated de novo in the tribe. We further show that this gene may evolve a highly conservative rice-specific function that contributes to the regulation difference between rice and other plant species in response to pathogen infections. Biologic analyses including gene silencing, pathologic analysis, and mutant characterization by transformation showed that the OsDR10-suppressed plants enhanced resistance to a broad spectrum of Xanthomonas oryzae pv. oryzae strains, which cause bacterial blight disease. This enhanced disease resistance was