PLANT BIOLOGY MicroRNA and Innate Immune Responses in Plants

Plants mount an innate immune response when they detect pathogen-associated molecular markers such as bacterial flagellin. Navarro et al. now show that in Arabidopsis, bacterial flagellin induces the expression of the microRNA miR393, which in turn reduces the expression of three auxin receptors and eventually leads to the down-regulation of auxin signaling pathways that are implicated in disease susceptibility. This down-regulation then increases the plant's resistance to infection. This miRNA expression seems to act in parallel with independent transcriptional repression of the auxin receptors to ensure that an immune response is generated.

L. Navarro, P. Dunoyer, F. Jay, B. Arnold, N. Dharmasiri, M. Estelle, O. Voinnet, J. D. G. Jones, A plant miRNA contributes to antibacterial resistance by repressing auxin signaling. Science 312, 436-439 (2006). [Abstract] [Full Text]

The editors suggest the following Related Resources on Science sites:

In Science Signaling

TEACHING RESOURCES
Model of the TIR1 Pathway for Auxin-Mediated Gene Expression

Marta Laskowski (14 February 2006)
Sci. STKE 2006 (322), tr1. [DOI: 10.1126/stke.3222006tr1]
 |  Abstract »  |  Full Text »  |  PDF »  |  Animation »

PERSPECTIVES
MicroRNA-Dependent Trans-Acting siRNA Production

Hervé Vaucheret (6 September 2005)
Sci. STKE 2005 (300), pe43. [DOI: 10.1126/stke.3002005pe43]
 |  Abstract »  |  Full Text »  |  PDF »