Plant biology

Infections and Defense

Science Signaling  12 May 2009:
Vol. 2, Issue 70, pp. ec163
DOI: 10.1126/scisignal.270ec163

Bacteria secrete effectors to suppress immunity in plant and animal hosts, resulting in an evolutionary arms race between bacteria and their eukaryotic hosts. One important aspect of plant immunity against bacteria is based on disease resistance protein complexes, which recognize specific bacterial effectors and activate signal transduction. A strain of the bacteria Pseudomonas that infects tomato and Arabidopsis plants injects its effector protein, AvrPtoB, into plant cells. Two plant protein kinases, Fen and Pto, then stimulate disease defense responses that may restrain or halt the infection. Ntoukakis et al. show that the balance between resistance and susceptibility triggered by AvrPtoB is determined by the kinase activity Pto within a disease resistance complex.

V. Ntoukakis, T. S. Mucyn, S. Gimenez-Ibanez, H. C. Chapman, J. R. Gutierrez, A. L. Balmuth, A. M. E. Jones, J. P. Rathjen, Host inhibition of a bacterial virulence effector triggers immunity to infection. Science 324, 784–787 (2009). [Abstract] [Full Text]