title: Salt stress response triggers activation of the jasmonate signaling pathway leading to inhibition of cell elongation in Arabidopsis primary root.
abstract: Salinity is a severe abiotic stress that affects irrigated croplands. Jasmonate (JA) is an essential hormone involved in plant defense against herbivory and in responses to abiotic stress. However, the relationship between the salt stress response and the JA pathway in Arabidopsis thaliana is not well understood at molecular and cellular levels. In this work we investigated the activation of JA signaling by NaCl and its effect on primary root growth. We found that JA-responsive JAZ genes were up-regulated by salt stress in a COI1-dependent manner in the roots. Using a JA-Ile sensor we demonstrated that activation of JA signaling by salt stress occurs in the meristematic zone and stele of the differentiation zone and that this activation was dependent on JAR1 and proteasome functions. Another finding is that the elongation zone (EZ) and its cortical cells were significantly longer in JA-related mutants (AOS, COI1, JAZ3 and MYC2/3/4 genes) compared with wild-type plants under salt stress, revealing the participation of the canonical JA signaling pathway. Noteworthy, osmotic stress - a component of salt stress - inhibited cell elongation in the EZ in a COI1-dependent manner. We propose that salt stress triggers activation of the JA signaling pathway followed by inhibition of cell elongation in the EZ. We have shown that salt-inhibited root growth partially involves the jasmonate signaling pathway in Arabidopsis.
authors.affiliation: Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3465548, Chile.
authors.forename: Camilo E
authors.initials: CE
authors.lastname: Valenzuela
authors.affiliation: Escuela de Biotecnología, Facultad de Ciencias, Universidad Santo Tomás, Santiago 8370003, Chile.
authors.forename: Orlando
authors.initials: O
authors.lastname: Acevedo-Acevedo
authors.affiliation: Escuela de Biotecnología, Facultad de Ciencias, Universidad Santo Tomás, Santiago 8370003, Chile.
authors.forename: Giovanna S
authors.initials: GS
authors.lastname: Miranda
authors.affiliation: Escuela de Biotecnología, Facultad de Ciencias, Universidad Santo Tomás, Santiago 8370003, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Vergara-Barros
authors.affiliation: Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331010, Chile.
authors.forename: Loreto
authors.initials: L
authors.lastname: Holuigue
authors.affiliation: Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3465548, Chile.
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Figueroa
authors.affiliation: Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3465548, Chile pabfigueroa@utalca.cl.
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Figueroa
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D054883:Oxylipins / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D055049:Salt Tolerance / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; C011006:jasmonic acid; D046988:Proteasome Endopeptidase Complex
keywords: Arabidopsis; jasmonate; osmotic stress; root; salt; signaling.