title: Cesium Toxicity Alters MicroRNA Processing and AGO1 Expressions in Arabidopsis thaliana.
abstract: MicroRNAs (miRNAs) are short RNA fragments that play important roles in controlled gene silencing, thus regulating many biological processes in plants. Recent studies have indicated that plants modulate miRNAs to sustain their survival in response to a variety of environmental stimuli, such as biotic stresses, cold, drought, nutritional starvation, and toxic heavy metals. Cesium and radio-cesium contaminations have arisen as serious problems that both impede plant growth and enter the food chain through contaminated plants. Many studies have been performed to define plant responses against cesium intoxication. However, the complete profile of miRNAs in plants during cesium intoxication has not been established. Here we show the differential expression of the miRNAs that are mostly down-regulated during cesium intoxication. Furthermore, we found that cesium toxicity disrupts both the processing of pri-miRNAs and AGONOUTE 1 (AGO1)-mediated gene silencing. AGO 1 seems to be especially destabilized by cesium toxicity, possibly through a proteolytic regulatory pathway. Our study presents a comprehensive profile of cesium-responsive miRNAs, which is distinct from that of potassium, and suggests two possible mechanisms underlying the cesium toxicity on miRNA metabolism.
authors.affiliation: Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon, 305-353, Republic of Korea.
authors.forename: Il Lae
authors.initials: IL
authors.lastname: Jung
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Copenhagen, Denmark.
authors.forename: Moonyoung
authors.initials: M
authors.lastname: Ryu
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Copenhagen, Denmark.
authors.forename: Seok Keun
authors.initials: SK
authors.lastname: Cho
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Copenhagen, Denmark.
authors.forename: Pratik
authors.initials: P
authors.lastname: Shah
authors.affiliation: Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon, 305-353, Republic of Korea.
authors.forename: Ju Hye
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Copenhagen, Denmark.
authors.forename: Hansol
authors.initials: H
authors.lastname: Bae
authors.affiliation: Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon, 305-353, Republic of Korea.
authors.forename: In Gyu
authors.initials: IG
authors.lastname: Kim
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg, Copenhagen, Denmark.
authors.forename: Seong Wook
authors.initials: SW
authors.lastname: Yang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics; D060565:Argonaute Proteins / Q000096:biosynthesis* / Q000235:genetics; D002586:Cesium / Q000633:toxicity*; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics*; D018517:Plant Roots / Q000254:growth & development; D011188:Potassium / Q000633:toxicity*
chemical_list: C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D035683:MicroRNAs; D002586:Cesium; D011188:Potassium