title: Functional analysis of rice NPR1-like genes reveals that OsNPR1/NH1 is the rice orthologue conferring disease resistance with enhanced herbivore susceptibility.
abstract: The key regulator of salicylic acid (SA)-mediated resistance, NPR1, is functionally conserved in diverse plant species, including rice (Oryza sativa L.). Investigation in depth is needed to provide an understanding of NPR1-mediated resistance and a practical strategy for the improvement of disease resistance in the model crop rice. The rice genome contains five NPR1-like genes. In our study, three rice homologous genes, OsNPR1/NH1, OsNPR2/NH2 and OsNPR3, were found to be induced by rice bacterial blight Xanthomonas oryzae pv. oryzae and rice blast Magnaporthe grisea, and the defence molecules benzothiadiazole, methyl jasmonate and ethylene. We confirmed that OsNPR1 is the rice orthologue by complementing the Arabidopsis npr1 mutant. Over-expression of OsNPR1 conferred disease resistance to bacterial blight, but also enhanced herbivore susceptibility in transgenic plants. The OsNPR1-green fluorescent protein (GFP) fusion protein was localized in the cytoplasm and moved into the nucleus after redox change. Mutations in its conserved cysteine residues led to the constitutive localization of OsNPR1(2CA)-GFP in the nucleus and also abolished herbivore hypersensitivity in transgenic rice. Different subcellular localizations of OsNPR1 antagonistically regulated SA- and jasmonic acid (JA)-responsive genes, but not SA and JA levels, indicating that OsNPR1 might mediate antagonistic cross-talk between the SA- and JA-dependent pathways in rice. This study demonstrates that rice has evolved an SA-mediated systemic acquired resistance similar to that in Arabidopsis, and also provides a practical approach for the improvement of disease resistance without the penalty of decreased herbivore resistance in rice.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yuexing
authors.initials: Y
authors.lastname: Yuan
authors.forename: Sihui
authors.initials: S
authors.lastname: Zhong
authors.forename: Qun
authors.initials: Q
authors.lastname: Li
authors.forename: Zengrong
authors.initials: Z
authors.lastname: Zhu
authors.forename: Yonggen
authors.initials: Y
authors.lastname: Lou
authors.forename: Linyou
authors.initials: L
authors.lastname: Wang
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
authors.forename: Muyang
authors.initials: M
authors.lastname: Wang
authors.forename: Qiaoli
authors.initials: Q
authors.lastname: Li
authors.forename: Donglei
authors.initials: D
authors.lastname: Yang
authors.forename: Zuhua
authors.initials: Z
authors.lastname: He
mesh_terms: D000085:Acetates / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics; D002467:Cell Nucleus / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology; D017753:Ecosystem; D017343:Genes, Plant; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D054883:Oxylipins; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C072239:methyl jasmonate; D020156:Salicylic Acid