'Evidence of an auxin signal pathway, microRNA167-ARF8-GH3, and its response to exogenous auxin in cultured rice cells'.
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.
Yang
Ji Hyun
JH
Department of Biological Science and the Basic Science Research Institute, Sungkyunkwan University, Suwon, Korea 440-746.
Han
So Jeong
SJ
Yoon
Eun Kyung
EK
Lee
Woo Sung
WS
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
D007210:Indoleacetic Acids; D035683:MicroRNAs; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors