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Author Sunkar, Ramanjulu ♦ Kapoor, Avnish ♦ Zhu, Jian-Kang
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Oxidative Stress Tolerance ♦ Cu Zn Superoxide Dismutase Gene ♦ Oxidative Stress ♦ Posttranscriptional Induction ♦ Important Role ♦ Mrna Cleavage ♦ Translational Inhibition ♦ Csd2 Transcript ♦ Diverse Physiological Process ♦ Cytosolic Csd1 ♦ Heavy Metal ♦ Mir398-resistant Form Ofcsd2 Accumulatemorecsd2mrna ♦ Oxidative Stress Condition ♦ Evidence Point ♦ Transgenic Arabidopsis Thaliana Plant ♦ Posttranscriptional Csd1 ♦ High Light ♦ Thatcsd1 Andcsd2 Expression ♦ Temporal Expression Pattern ♦ Fine-tuned Bymir398-directed Mrna Cleavage ♦ Potential Role ♦ Related Cu Zn Superoxide Dismutases ♦ Effective New Approach ♦ Mir398 Target ♦ Classof Regulatoryrnasof ♦ Transgenic Plant ♦ Superoxide Radical ♦ Plant Productivity ♦ Csd2mrna Accumulation ♦ Relievingmir398-guided Suppression Ofcsd2 ♦ Chloroplastic Csd2 ♦ Thatmir398 Expression
Abstract MicroRNAs (miRNAs) are a classof regulatoryRNAsof;21nucleotides that posttranscriptionally regulate gene expressionby directing mRNA cleavage or translational inhibition. Increasing evidence points to a potential role of miRNAs in diverse physiological processes. miR398 targets two closely related Cu/Zn superoxide dismutases (cytosolic CSD1 and chloroplastic CSD2) that can detoxify superoxide radicals. CSD1 and CSD2 transcripts are induced in response to oxidative stress, but the regulatorymechanism of the induction is unknown. Here, we show thatmiR398 expression is downregulated transcriptionally by oxidative stresses, and this downregulation is important for posttranscriptional CSD1 and CSD2mRNA accumulation and oxidative stress tolerance. We also provide evidence for an important role of miR398 in specifying the spatial and temporal expression patterns ofCSD1 andCSD2mRNAs. Our results suggest thatCSD1 andCSD2 expression is fine-tuned bymiR398-directed mRNA cleavage. Additionally, we show that transgenic Arabidopsis thaliana plants overexpressing a miR398-resistant form ofCSD2 accumulatemoreCSD2mRNA than plants overexpressing a regularCSD2 and are consequently much more tolerant to high light, heavy metals, and other oxidative stresses. Thus, relievingmiR398-guided suppression ofCSD2 in transgenic plants is an effective new approach to improving plant productivity under oxidative stress conditions.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Publisher Date 2006-01-01