title: Jasmonoyl isoleucine accumulation is needed for abscisic acid build-up in roots of Arabidopsis under water stress conditions.
abstract: Phytohormones are central players in sensing and signalling numerous environmental conditions like drought. In this work, hormone profiling together with gene expression of key enzymes involved in abscisic acid (ABA) and jasmonate biosynthesis were studied in desiccating Arabidopsis roots. Jasmonic acid (JA) content transiently increased after stress imposition whereas progressive and concomitant ABA and Jasmonoyl Isoleucine (JA-Ile) accumulations were detected. Molecular data suggest that, at least, part of the hormonal regulation takes place at the biosynthetic level. These observations also point to a possible involvement of jasmonates on ABA biosynthesis under stress. To test this hypothesis, mutants impaired in jasmonate biosynthesis (opr3, lox6 and jar1-1) and in JA-dependent signalling (coi1) were employed. Results showed that the early JA accumulation leading to JA-Ile build up was necessary for an ABA increase in roots under two different water stress conditions. Signal transduction between water stress-induced JA-Ile accumulation and COI1 is necessary for a full induction of the ABA biosynthesis pathway and subsequent hormone accumulation in roots of Arabidopsis plants. The present work adds a level of interaction between jasmonates and ABA at the biosynthetic level.
authors: Departamento de Ciencias Agrarias y del Medio Natural, Universitat Jaume I, Campus Riu Sec, Castelló de la Plana, E-12071, Spain.
authors: Carlos
authors: C
authors: de Ollas
authors: Departamento de Ciencias Agrarias y del Medio Natural, Universitat Jaume I, Campus Riu Sec, Castelló de la Plana, E-12071, Spain.
authors: Vicent
authors: V
authors: Arbona
authors: Departamento de Ciencias Agrarias y del Medio Natural, Universitat Jaume I, Campus Riu Sec, Castelló de la Plana, E-12071, Spain.
authors: Aurelio
authors: A
authors: Gómez-Cadenas
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D003681:Dehydration; D055864:Droughts; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D014867:Water / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; D014867:Water; C011006:jasmonic acid; D000040:Abscisic Acid
keywords: coi1-16; drought; hormone signal transduction; jar1-1; jasmonates