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Plant Cell Rep (2013) 32:733740 DOI 10.1007/s00299-013-1425-2
REVIEW
Micro-regulators of auxin action
Neeti Sanan-Mishra Srichakradhar P. R. M. Varanasi
Sunil K. Mukherjee
Received: 31 December 2012 / Revised: 11 March 2013 / Accepted: 13 March 2013 / Published online: 31 March 2013 Springer-Verlag Berlin Heidelberg 2013
Abstract microRNAs (miRs) are 21- to 24-nucleotide-long RNA molecules that are mainly involved in regulating the gene expression at the post-transcriptional levels. They are present in a variety of organisms from algae to plants and play an important role in gene regulation. The identication of several diverging and converging functions of miRs indicates that they play versatile roles in regulating plant development including differentiation, organ development, phase change, signalling, disease resistance and response to environmental stresses. This article provides a concise update on the plant miR functions and their targets in the auxin pathway with focus on the interactions between miRs and auxin signalling to intricately regulate the plant responses.
Keywords MicroRNAs Auxin Plant Biogenesis
Mirtrons Functions Interaction
Introduction
The discovery of the RNAi pathway and endogenous non-coding RNA molecules has made the regulatory role for
RNA sonorously clear. These 19- to 24-nt-long, small RNAs (sRNAs) regulate growth and development as well as offer cellular protection against stressful environment and parasitic nucleic acid sequences. The sRNAs are implicated in modulating gene regulation through chromatin modication, transcript cleavage and translational repression (Carrington and Ambros 2003; Mallory and Vaucheret 2006; Vazquez et al. 2010). They carry out genetic as well as epigenetic alterations on the one hand and maintain the integrity of genomes to govern organism architecture and organ development on the other (Agrawal et al. 2003; Feng et al. 2010).
The microRNAs (miRs) constitute a major class of the sRNAs. Several citations are now available on the role of miRs in regulating the environmental adaptations in plants. The discovery of lin-4 and let-7, as post-transcriptional regulators of the heterochronic gene, lin-14, involved in controlling developmental timing and cellular differentiation in Caenorhabditis elegans marked the identication of miRs (Lee et al. 1993; Reinhart et al. 2000). Although these ndings initiated the discovery of miRs, their presence in plants was rst reported in 2002 simultaneously by different groups (Llave et al. 2002; Park et al. 2002; Reinhart et al. 2002). Since then...