Plant biology

Indirect Defenses

Science's STKE  21 Jun 2005:
Vol. 2005, Issue 289, pp. tw230
DOI: 10.1126/stke.2892005tw230

Some plants defend against fungal infection by using the hypersensitive response, in which plant cells at the site of invasion are killed off to retard spread of the infection. The process relies upon an elicitor from the pathogen and a corresponding resistance gene in the plant. When Cladosporium fulvum infects tomato leaves, these two factors do not, however, seem to interact directly. Rooney et al. analyze the function of the plant protease Rcr3 in mediating the defense response. The pathogen avirulence factor, Avr, is secreted extracellularly, where it interacts with the tomato plant Rcr3 protease. Together, this interaction signals to the membrane-bound host resistance factor, Cf-2, to initiate plant defense responses.

H. C. E. Rooney, J. W. van 't Klooster, R. A. L. van der Hoorn, M. H. A. J. Joosten, J. D. G. Jones, P. J. G. M. de Wit, Cladosporium Avr2 inhibits tomato Rcr3 protease required for Cf-2-dependent disease resistance. Science 308, 1783-1786 (2005). [Abstract] [Full Text]