Alternative Polyadenylation and Salicylic Acid Modulate Root Responses to Low Nitrogen Availability
Carlos M. Conesa,
Angela Saez,
Sara Navarro-Neila,
Laura de Lorenzo,
Arthur G. Hunt,
Edgar B. Sepúlveda,
Roberto Baigorri,
Jose M. Garcia-Mina,
Angel M. Zamarreño,
Soledad Sacristán,
Juan C. del Pozo
Affiliations
Carlos M. Conesa
Centro de Biotecnología y Genómica de Plantas (CBGP), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
Angela Saez
DTD Development and Technical Department, Timac Agro Spain, 31580 Lodosa, Navarra, Spain
Sara Navarro-Neila
Centro de Biotecnología y Genómica de Plantas (CBGP), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
Laura de Lorenzo
Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312, USA
Arthur G. Hunt
Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312, USA
Edgar B. Sepúlveda
Departamento de Biotecnología y Bioingeniería CINVESTAV Instituto Politécnico Nacional, 07360 Ciudad de Mexico, Mexico
Roberto Baigorri
DTD Development and Technical Department, Timac Agro Spain, 31580 Lodosa, Navarra, Spain
Jose M. Garcia-Mina
Environmental Biology Department, University of Navarra, 31008 Navarra, Spain
Angel M. Zamarreño
Environmental Biology Department, University of Navarra, 31008 Navarra, Spain
Soledad Sacristán
Centro de Biotecnología y Genómica de Plantas (CBGP) and Escuela Técnica Superior de Ingeniería Agronómica, Agroambiental y de Biosistemas (ETSIAAB), Universidad Polictécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
Juan C. del Pozo
Centro de Biotecnología y Genómica de Plantas (CBGP), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
Nitrogen (N) is probably the most important macronutrient and its scarcity limits plant growth, development and fitness. N starvation response has been largely studied by transcriptomic analyses, but little is known about the role of alternative polyadenylation (APA) in such response. In this work, we show that N starvation modifies poly(A) usage in a large number of transcripts, some of them mediated by FIP1, a component of the polyadenylation machinery. Interestingly, the number of mRNAs isoforms with poly(A) tags located in protein-coding regions or 5′-UTRs significantly increases in response to N starvation. The set of genes affected by APA in response to N deficiency is enriched in N-metabolism, oxidation-reduction processes, response to stresses, and hormone responses, among others. A hormone profile analysis shows that the levels of salicylic acid (SA), a phytohormone that reduces nitrate accumulation and root growth, increase significantly upon N starvation. Meta-analyses of APA-affected and fip1-2-deregulated genes indicate a connection between the nitrogen starvation response and salicylic acid (SA) signaling. Genetic analyses show that SA may be important for preventing the overgrowth of the root system in low N environments. This work provides new insights on how plants interconnect different pathways, such as defense-related hormonal signaling and the regulation of genomic information by APA, to fine-tune the response to low N availability.