Editors' ChoiceMOLECULAR BIOLOGY

RNA Interference and Plant Defenses

Science Signaling  19 Aug 2008:
Vol. 1, Issue 33, pp. ec297
DOI: 10.1126/scisignal.133ec297

RNA interference plays an important role in innate immunity in plants and in animals. Specific microRNAs have also been implicated in pathways that sense pathogen-associated molecular patterns (PAMPs). Now, Navarro et al. examine in more detail the role of microRNAs in innate immunity in Arabidopsis. MicroRNAs were found to be more broadly required for PAMP sensing. Pathogenic bacteria appear to have evolved various effectors that are secreted into the host that suppress the microRNA pathway at various points. Infection with turnip mosaic virus, which produces a suppressor of both the small interfering RNA and microRNA pathways, promotes infection by nonpathogenic bacteria, which may explain the observed synergy between viral and bacterial pathogens seen in the field.

L. Navarro, F. Jay, K. Nomura, S. Y. He, O. Voinnet, Suppression of the microRNA pathway by bacterial effector proteins. Science 321, 964-967 (2008). [Abstract] [Full Text]