Qujiang Wen, Yuling Meng and Weixing Shan
College of Plant Protection and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
Phytophthora species belong to a unique class of eukaryotic microorganisms called oomycetes that are morphologically similar to but phylogenetically distant from true fungi. Phytophthora species cause enormous crop losses and damages to natural ecosystems. For example, the Irish Famine causal agent Phytophthora infestans has still been a worldwide major threat to sustainable potato production, owing largely to capability of the pathogen in erasing efficiency of disease resistance genes. Disease resistance is usually achieved by plant recognition of pathogen effectors. Disruption of such recognition, more frequently by genetic or epigenetic changes of expression of recognized effector genes in the pathogen, leads to loss of disease resistance. In this report, we describe an approach for engineering disease resistance in plants against Phytophthora pathogens. Plants encode small secreted proteins in response to stresses, which potentially play a function in triggering resistance, similar to pathogen effectors. Global striking changes in host plant gene expression are well documented in response to pathogen infection. We show that engineered resistance genes based on combinations of a plant cis element highly and specifically responsive to Phytophthora infection and small defense related protein genes lead to high level of resistance to infections by Phytophthora pathogens. The engineered disease resistance to broad-spectrum and is potentially durable. Our results show a novel approach for exploring plant endogenous small proteins in engineering durable and broad-spectrum plant disease resistance against pathogens.