Identification of MicroRNA 395a in 24-Epibrassinolide-Regulated Root Growth of Arabidopsis thaliana Using MicroRNA Arrays

International Journal of Molecular Sciences

Li-Ling Lin²  Chia-Chi Wu⁴  Hsuan-Cheng Huang³  Huai-Ju Chen¹  Hsu-Liang Hsieh¹ 

[1] Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan; E-Mail:;Department of Life Science, National Taiwan University, Taipei 106, Taiwan; E-Mail:;Institute of Biomedical Informatics, Center for Systems and Synthetic Biology, National Yang-Ming University, Taipei 112, Taiwan;Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 106, Taiwan; E-Mail:

关键词: brassinosteroids;    miR395a;    root growth;    Arabidopsis thaliana;    microRNA array;   

DOI  :  10.3390/ijms140714270

来源: mdpi

【 摘 要 】

Brassinosteroids (BRs) are endogenous plant hormones and are essential for normal plant growth and development. MicroRNAs (miRNAs) of Arabidopsis thaliana are involved in mediating cell proliferation in leaves, stress tolerance, and root development. The specifics of BR mechanisms involving miRNAs are unknown. Using customized miRNA array analysis, we identified miRNAs from A. thaliana ecotype Columbia (Col-0) regulated by 24-epibrassinolide (EBR, a highly active BR). We found that miR395a was significantly up-regulated by EBR treatment and validated its expression under these conditions. miR395a was over expressed in leaf veins and root tissues in EBR-treated miR395a promoter::GUS plants. We integrated bioinformatics methods and publicly available DNA microarray data to predict potential targets of miR395a. GUN5—a multifunctional protein involved in plant metabolic functions such as chlorophyll synthesis and the abscisic acid (ABA) pathway—was identified as a possible target. ABI4 and ABI5, both genes positively regulated by ABA, were down-regulated by EBR treatment. In summary, our results suggest that EBR regulates seedling development and root growth of A. thaliana through miR395a by suppressing GUN5 expression and its downstream signal transduction.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland