Editors' ChoicePlant biology

Keeping Fungal Invaders at Bay

Science Signaling  06 Jan 2009:
Vol. 2, Issue 52, pp. ec5
DOI: 10.1126/scisignal.252ec5

Plant cells mobilize a cell-autonomous response to the sites of attempted fungal penetration, resulting in the polarization of the peroxisome. The mechanism driving this polarization has remained unclear. Now Clay et al. and Bednarek et al. show that the preinvasion resistance mechanism is due to the coordinated and infection-induced biosynthesis of a specific glucosinolate molecule. This molecule is made and delivered to the outside of the cell through the action of the peroxisomal proteins (PEN2 and PEN3) and is produced via a biochemical reaction that uses myrosinase products as a substrate. Bednarek et al. show that derived compounds of PEN2 play a key role as antifungal compounds and that this route of synthesis occurs in living cells and only in response to infection. Clay et al. have discovered how these myrosinases and their related breakdown products act as signaling molecules in the Arabidopsis defense response. Thus, a family of metabolites controls this nonhost resistance pathway.

P. Bednarek, M. Piślewska-Bednarek, A. Svatoš, B. Schneider, J. Doubský, M. Mansurova, M. Humphry, C. Consonni, R. Panstruga, A. Sanchez-Vallet, A. Molina, P. Schulze-Lefert, A glucosinolate metabolism pathway in living plant cells mediates broad-spectrum antifungal defense. Science 323, 101–106 (2009). [Abstract] [Full Text]

N. K. Clay, A. M. Adio, C. Denoux, G. Jander, F. M. Ausubel, Glucosinolate metabolites required for an Arabidopsis innate immune response. Science 323, 95–101 (2009). [Abstract] [Full Text]