Plant biology

MicroRNA and Innate Immune Responses in Plants

Science's STKE  25 Apr 2006:
Vol. 2006, Issue 332, pp. tw141
DOI: 10.1126/stke.3322006tw141

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]