201. 'Evidence of an auxin signal pathway, microRNA167-ARF8-GH3, and its response to exogenous auxin in cultured rice cells'
- Author
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Eun Kyung Yoon, So Jeong Han, Ji Hyun Yang, and Woo Sung Lee
- Subjects
Biology ,Gene Expression Regulation, Enzymologic ,Article ,chemistry.chemical_compound ,Plant Growth Regulators ,Auxin ,Gene Expression Regulation, Plant ,microRNA ,Genetics ,heterocyclic compounds ,RNA, Messenger ,Transcription factor ,Cells, Cultured ,Plant Proteins ,chemistry.chemical_classification ,Regulation of gene expression ,Messenger RNA ,Growth medium ,Indoleacetic Acids ,fungi ,RNA ,food and beverages ,Oryza ,MicroRNAs ,chemistry ,Biochemistry ,Signal transduction ,Signal Transduction ,Transcription Factors - 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.
- Published
- 2006