title: Regulation of auxin response by miR393-targeted transport inhibitor response protein                      1 is involved in normal development in Arabidopsis.
abstract: miR393, which is encoded by MIR393a and MIR393b in Arabidopsis, post-transcriptionally regulates mRNAs for the F-box auxin receptors TIR1 (Transport Inhibitor Response Protein 1), AFB1 (Auxin Signaling F-box Protein 1), AFB2 and AFB3. However, biological functions of the miR393-TIR1/AFBs module in auxin response and plant development is not fully understood. In the study herein, we demonstrate that miR393 accumulated in response to exogenous IAA treatment, and its induction was due to enhanced MIR393b transcription but not MIR393a. Overexpression of a miR393-resistant form of TIR1 (mTIR1) enhanced auxin sensitivity and led to pleiotropic effects on plant development including inhibition of primary root growth, overproduction of lateral roots, altered leave phenotype and delayed flowering. Furthermore, miR393 level was increased in 35S:mTIR1 plant, suggesting that TIR1 promoted the expression of miR393 by a feedback loop. The interaction between miR393 and its target indicates a fine adjustment to the roles of the miR393-TIR1 module, which is required for auxin responses in plant development.
authors: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
authors: Zhe-Hao
authors: ZH
authors: Chen
authors: Mao-Lin
authors: ML
authors: Bao
authors: Yu-Zhe
authors: YZ
authors: Sun
authors: Yan-Jun
authors: YJ
authors: Yang
authors: Xiao-Hong
authors: XH
authors: Xu
authors: Jun-Hui
authors: JH
authors: Wang
authors: Ning
authors: N
authors: Han
authors: Hong-Wu
authors: HW
authors: Bian
authors: Mu-Yuan
authors: MY
authors: Zhu
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D044783:F-Box Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D007210:Indoleacetic Acids / Q000494:pharmacology*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D044783:F-Box Proteins; D007210:Indoleacetic Acids; C559857:MIRN393 microRNA, Arabidopsis; D035683:MicroRNAs; D011956:Receptors, Cell Surface; C501405:TIR1 protein, Arabidopsis