title: Expression and functional analyses of microRNA417 in Arabidopsis thaliana under stress conditions.
abstract: MicroRNAs (miRNAs) are 20-25 nucleotides-long RNA transcripts that are capable of suppressing target gene expression by either mRNA cleavage or translational repression. Although many recent reports propose that miRNAs play diverse roles in growth, development, morphogenesis, and stress responses of plants, the biological roles of many miRNAs remain to be verified. Here, we investigated stress-responsive expression patterns and functional roles of miRNA417 in seed germination and seedling growth of Arabidopsis thaliana under various abiotic stress conditions. miRNA417 was expressed constantly throughout the entire growth stages and ubiquitously in all organs including stems, roots, leaves, and flowers. The expression of miRNA417 was regulated by salt stress, dehydration stress, or abscisic acid treatment. To examine the biological roles of miRNA417 in stress responses, the transgenic Arabidopsis plants that constitutively overexpress miRNA417 under the control of cauliflower mosaic virus 35S promoter were generated, and their phenotypes were analyzed under stress conditions. Results showed that seed germination of the transgenic plants was retarded compared with the wild-type plants in the presence of high salt or abscisic acid. These results imply that miRNA417 plays a role as a negative regulator of seed germination in Arabidopsis plants under salt stress conditions.
authors.affiliation: Department of Plant Biotechnology, Agricultural Plant Stress Research Center and Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Jung
authors.forename: Hunseung
authors.initials: H
authors.lastname: Kang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D015152:Blotting, Northern; D004190:Disasters; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D010937:Plant Growth Regulators / Q000494:pharmacology; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature
chemical_list: D035683:MicroRNAs; D010937:Plant Growth Regulators; D018749:RNA, Plant; D012965:Sodium Chloride; D000040:Abscisic Acid