title: Sucrose-mediated priming of plant defense responses and broad-spectrum disease resistance by overexpression of the maize pathogenesis-related PRms protein in rice plants.
abstract: Expression of pathogenesis-related (PR) genes is part of the plant's natural defense response against pathogen attack. The PRms gene encodes a fungal-inducible PR protein from maize. Here, we demonstrate that expression of PRms in transgenic rice confers broad-spectrum protection against pathogens, including fungal (Magnaporthe oryzae, Fusarium verticillioides, and Helminthosporium oryzae) and bacterial (Erwinia chrysanthemi) pathogens. The PRms-mediated disease resistance in rice plants is associated with an enhanced capacity to express and activate the natural plant defense mechanisms. Thus, PRms rice plants display a basal level of expression of endogenous defense genes in the absence of the pathogen. PRms plants also exhibit stronger and quicker defense responses during pathogen infection. We also have found that sucrose accumulates at higher levels in leaves of PRms plants. Sucrose responsiveness of rice defense genes correlates with the pathogen-responsive priming of their expression in PRms rice plants. Moreover, pretreatment of rice plants with sucrose enhances resistance to M. oryzae infection. Together, these results support a sucrose-mediated priming of defense responses in PRms rice plants which results in broad-spectrum disease resistance.
authors.affiliation: Departamento de Genética Molecular, Laboratorio de Genética Molecular Vegetal, Consorcio CSIC-IRTA, Jordi Girona 18, 08034 Barcelona, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Gómez-Ariza
authors.forename: Sonia
authors.initials: S
authors.lastname: Campo
authors.forename: Mar
authors.initials: M
authors.lastname: Rufat
authors.forename: Montserrat
authors.initials: M
authors.lastname: Estopà
authors.forename: Joaquima
authors.initials: J
authors.lastname: Messeguer
authors.forename: Blanca
authors.initials: B
authors.lastname: San Segundo
authors.forename: María
authors.initials: M
authors.lastname: Coca
mesh_terms: D005670:Fusarium / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006375:Helminthosporium / Q000254:growth & development; D015151:Immunoblotting; D020082:Magnaporthe / Q000254:growth & development; D012275:Oryza / Q000235:genetics* / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology*; D003313:Zea mays / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D013395:Sucrose