摘要
Study on the regulation of broad-spectrum resistance is an active area in plant biology. RESISTANCE TO POWDERY MILDEW 8.1(RPW8.1)is one of a few broad-spectrum resistance genes triggering the hypersensitive response(HR) to restrict multiple pathogenic infections. To address the question how RPW8.1 signaling is regulated,we performed a genetic screen and tried to identify mutations enhancing RPW8.1-mediated HR.Here, we provided evidence to connect an annexin protein with RPW8.1-mediated resistance in Arabidopsis against powdery mildew. We isolated and characterized Arabidopsis b7-6 mutant.A point mutation in b7-6 at the At5 g12380 locus resulted in an amino acid substitution in ANNEXIN8(AtANN8). Loss-of-function or RNA-silencing of AtANN8 led to enhanced expression of RPW8.1,RPW8.1-dependent necrotic lesions in leaves, and defense against powdery mildew. Conversely,over-expression of AtANN8 compromised RPW8.1-mediated disease resistance and cell death. Interestingly, the mutation in AtANN8 enhanced RPW8.1-triggered H2O2. In addition, mutation in AtANN8 led to hypersensitivity to salt stress. Together, our data indicate that AtANN8 is involved in multiple stress signaling pathways and negatively regulates RPW8.1-mediated resistance against powdery mildew and cell death, thus linking ANNEXIN’s function with plant immunity.
基金
supported by the National Natural Science Foundation of China (Grant numbers 31672090, 31430072 and 31371931 to W.-M.W.)
the National Science Foundation (Grant numbers IOS-1457033 and IOS-1901566 to S. X.)。
