title: Expression profiling of Chondrus crispus (Rhodophyta) after exposure to methyl jasmonate.
abstract: Methyl jasmonate (MeJA) is a plant hormone important for the mediation of signals for developmental processes and defence reactions in higher plants. The effects of MeJA and the signalling pathways on other photosynthetic organism groups are largely unknown, even though MeJA may have very important roles. Therefore the effects of MeJA in a red alga were studied. A medium-scale expression profiling approach to identify genes regulated by MeJA in the red seaweed Chondrus crispus is described here. The expression profiles were studied 0, 2, 4, 6, 12, and 24 h after the addition of MeJA to the seawater surrounding the algae. The changes in the transcriptome were monitored using cDNA microarrays with 1920 different cDNA representing 1295 unique genes. The responses of selected genes were verified with real-time PCR and the correlation between the two methods was generally satisfying. The study showed that 6% of genes studied showed a response to the addition of MeJA and the most dynamic response was seen after 6 h. Genes that showed up-regulation included several glutathione S-transferases, heat shock protein 20, a xenobiotic reductase, and phycocyanin lyase. Down-regulated transcripts included glucose kinase, phosphoglucose isomerase, and a ribosomal protein. A comparison between different functional groups showed an up-regulation of stress-related genes and a down-regulation of genes involved in energy conversion and general metabolism. It is concluded that MeJA, or a related compound, has a physiological role as a stress hormone in red algae. This study represents to our knowledge the first analysis of gene expression using cDNA microarrays in a red macroalga.
authors.affiliation: Centre National de la Recherche Scientifique, Université Pierre et Marie Curie-Paris 6, Laboratoire International Associé-Dispersal and Adaptation in Marine Species, Unité Mixte de Recherche 7139, France. collen@sb.roscoff.fr
authors.forename: Jonas
authors.initials: J
authors.lastname: Collén
authors.forename: Cécile
authors.initials: C
authors.lastname: Hervé
authors.forename: Isabelle
authors.initials: I
authors.lastname: Guisle-Marsollier
authors.forename: Jean J
authors.initials: JJ
authors.lastname: Léger
authors.forename: Catherine
authors.initials: C
authors.lastname: Boyen
mesh_terms: D000085:Acetates / Q000494:pharmacology*; D020418:Algal Proteins / Q000235:genetics* / Q000378:metabolism; D044723:Chondrus / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D016000:Cluster Analysis; D003517:Cyclopentanes / Q000494:pharmacology*; D020869:Gene Expression Profiling; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins; D010937:Plant Growth Regulators / Q000494:pharmacology*; D016133:Polymerase Chain Reaction
chemical_list: D000085:Acetates; D020418:Algal Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; C072239:methyl jasmonate