title: Lemna minor plants chronically exposed to ionising radiation: RNA-seq analysis indicates a dose rate dependent shift from acclimation to survival strategies.
abstract: Ecotoxicological research provides knowledge on ionising radiation-induced responses in different plant species. However, the sparse data currently available are mainly extracted from acute exposure treatments. To provide a better understanding of environmental exposure scenarios, the response to stress in plants must be followed in more natural relevant chronic conditions. We previously showed morphological and biochemical responses in Lemna minor plants continuously exposed for 7days in a dose-rate dependent manner. In this study responses on molecular (gene expression) and physiological (photosynthetic) level are evaluated in L. minor plants exposed to ionising radiation. To enable this, we examined the gene expression profiles of irradiated L. minor plants by using an RNA-seq approach. The gene expression data reveal indications that L. minor plants exposed at lower dose rates, can tolerate the exposure by triggering acclimation responses. In contrast, at the highest dose rate tested, a high number of genes related to antioxidative defense systems, DNA repair and cell cycle were differentially expressed suggesting that only high dose rates of ionising radiation drive L. minor plants into survival strategies. Notably, the photosynthetic process seems to be unaffected in L. minor plants among the tested dose rates. This study, supported by our earlier work, clearly indicates that plants shift from acclimation responses towards survival responses at increasing dose rates of ionising radiation.
authors.affiliation: SCK●CEN, Boeretang, 200 2400, Mol, Belgium; Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium. Electronic address: Arne.vanhoeck@sckcen.be.
authors.forename: Arne
authors.initials: A
authors.lastname: Van Hoeck
authors.affiliation: SCK●CEN, Boeretang, 200 2400, Mol, Belgium; Centre for Environmental Research, University of Hasselt, Universiteitslaan 1, 3590 Diepenbeek, Belgium. Electronic address: nele.horemans@sckcen.be.
authors.forename: Nele
authors.initials: N
authors.lastname: Horemans
authors.affiliation: SCK●CEN, Boeretang, 200 2400, Mol, Belgium. Electronic address: robin.nauts@sckcen.be.
authors.forename: Robin
authors.initials: R
authors.lastname: Nauts
authors.affiliation: SCK●CEN, Boeretang, 200 2400, Mol, Belgium. Electronic address: may.vanhees@sckcen.be.
authors.forename: May
authors.initials: M
authors.lastname: Van Hees
authors.affiliation: SCK●CEN, Boeretang, 200 2400, Mol, Belgium. Electronic address: hildegarde.vandenhove@sckcen.be.
authors.forename: Hildegarde
authors.initials: H
authors.lastname: Vandenhove
authors.affiliation: Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium. Electronic address: ronny.blust@uantwerpen.be.
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
mesh_terms: D000064:Acclimatization / Q000235:genetics* / Q000528:radiation effects*; D029064:Araceae / Q000235:genetics* / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects*; D030541:Databases, Genetic; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D063990:Gene Ontology; D017343:Genes, Plant; D008027:Light; D015201:Meta-Analysis as Topic; D008954:Models, Biological; D010788:Photosynthesis / Q000235:genetics / Q000528:radiation effects; D010860:Pigments, Biological / Q000378:metabolism; D011839:Radiation, Ionizing; D017423:Sequence Analysis, RNA; D015398:Signal Transduction / Q000235:genetics / Q000528:radiation effects
chemical_list: D010860:Pigments, Biological
keywords: DNA damage; Duckweed; Ionising radiation; Oxidative stress; Radiation effects