Cesium Toxicity Alters MicroRNA Processing and AGO1 Expressions in Arabidopsis thaliana

• Published in: PloS one Vol. 10; no. 5; p. e0125514
• Main Authors: Jung, Il Lae, Ryu, Moonyoung, Cho, Seok Keun, Shah, Pratik, Lee, Ju Hye, Bae, Hansol, Kim, In Gyu, Yang, Seong Wook
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.05.2015; Public Library of Science (PLoS)
• Subjects: Arabidopsis; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - biosynthesis; Arabidopsis Proteins - genetics; Arabidopsis thaliana; Argonaute Proteins - biosynthesis; Argonaute Proteins - genetics; Binding sites; Biological activity; Biology; Cesium; Cesium - toxicity; Drought; Environmental aspects; Environmental effects; Environmental science; Food chains; Food contamination; Food plants; Gene expression; Gene Expression Regulation, Plant; Gene silencing; Genomes; Genomics; Health aspects; Heavy metals; Homeostasis; Identification; Intoxication; Metabolism; MicroRNA; MicroRNAs; MicroRNAs - genetics; miRNA; Physiological aspects; Physiology; Phytotoxicity; Plant growth; Plant Roots - growth & development; Plants (botany); Potassium; Potassium - toxicity; Proteins; Proteolysis; Ribonucleic acid; Risk factors; RNA; Soil contamination; Starvation; Toxicity; Trace elements; Denmark; South Korea
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0125514

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.