title: Transcriptome analysis reveals regulatory networks underlying differential susceptibility to Botrytis cinerea in response to nitrogen availability in Solanum lycopersicum.
abstract: Nitrogen (N) is one of the main limiting nutrients for plant growth and crop yield. It is well documented that changes in nitrate availability, the main N source found in agricultural soils, influences a myriad of developmental programs and processes including the plant defense response. Indeed, many agronomical reports indicate that the plant N nutritional status influences their ability to respond effectively when challenged by different pathogens. However, the molecular mechanisms involved in N-modulation of plant susceptibility to pathogens are poorly characterized. In this work, we show that Solanum lycopersicum defense response to the necrotrophic fungus Botrytis cinerea is affected by plant N availability, with higher susceptibility in nitrate-limiting conditions. Global gene expression responses of tomato against B. cinerea under contrasting nitrate conditions reveals that plant primary metabolism is affected by the fungal infection regardless of N regimes. This result suggests that differential susceptibility to pathogen attack under contrasting N conditions is not only explained by a metabolic alteration. We used a systems biology approach to identify the transcriptional regulatory network implicated in plant response to the fungus infection under contrasting nitrate conditions. Interestingly, hub genes in this network are known key transcription factors involved in ethylene and jasmonic acid signaling. This result positions these hormones as key integrators of nitrate and defense against B. cinerea in tomato plants. Our results provide insights into potential crosstalk mechanisms between necrotrophic defense response and N status in plants.
authors.affiliation: Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile Santiago, Chile ; Millennium Nucleus Center for Plant Systems and Synthetic Biology Santiago, Chile.
authors.forename: Andrea
authors.initials: A
authors.lastname: Vega
authors.affiliation: Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile ; Millennium Nucleus for Fungal Integrative and Synthetic Biology Santiago, Chile.
authors.forename: Paulo
authors.initials: P
authors.lastname: Canessa
authors.affiliation: Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile Santiago, Chile ; Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Hoppe
authors.affiliation: Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile Santiago, Chile.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Retamal
authors.affiliation: Millennium Nucleus Center for Plant Systems and Synthetic Biology Santiago, Chile ; Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile.
authors.forename: Tomas C
authors.initials: TC
authors.lastname: Moyano
authors.affiliation: Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile Valdivia, Chile.
authors.forename: Javier
authors.initials: J
authors.lastname: Canales
authors.affiliation: Millennium Nucleus Center for Plant Systems and Synthetic Biology Santiago, Chile ; Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile.
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Gutiérrez
authors.affiliation: Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile Santiago, Chile.
authors.forename: Joselyn
authors.initials: J
authors.lastname: Rubilar
keywords: defense mechanisms; ethylene signaling; gene network analysis; jasmonic acid; microarray analysis; nitrate nutrition; tomato