title: 'Evidence of an auxin signal pathway, microRNA167-ARF8-GH3, and its response to exogenous auxin in cultured rice cells'.
abstract: MicroRNA167 (miR167) was shown to cleave auxin responsive factor 8 (ARF8) mRNA in cultured rice cells. MiR167 level was found to be controlled by the presence of auxin in the growth medium. When cells grew in auxin-free medium, miR167 level decreased, resulting in an increase in the level of ARF8 mRNA. Cells growing in the normal growth medium containing auxin showed a reversed trend. It was also shown that expression of OsGH3-2, an rice IAA-conjugating enzyme, was positively regulated by ARF8. Delivery of synthesized miR167 into cells led to decrease of both ARF8 mRNA and OsGH3-2 mRNA. This study provides an evidence in which the exogeneous auxin signal is transduced to OsGH3-2 through miR167 and ARF8 in sequence. This proposed auxin signal transduction pathway, auxin-miR167-ARF8-OsGH3-2, could be, in conjunction with the other microRNA-mediated auxin signals, an important one for responding to exogeneous auxin and for determining the cellular free auxin level which guides appropriate auxin responses.
authors.affiliation: Department of Biological Science and the Basic Science Research Institute, Sungkyunkwan University, Suwon, Korea 440-746.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Yang
authors.forename: So Jeong
authors.initials: SJ
authors.lastname: Han
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Yoon
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Lee
mesh_terms: D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000494:pharmacology*; D035683:MicroRNAs / Q000378:metabolism*; D012275:Oryza / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D035683:MicroRNAs; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors