Xanthomonas campestris attenuates virulence by sensing light through a bacteriophytochrome photoreceptor

Bonomi, Hernán Ruy
Toum, Laila
Sycz, Gabriela
Sieira, Rodrigo
Toscani, Andrés Martin
Gudesblat, Gustavo Eduardo
Leskow, Federico C.
Goldbaum, Fernando Alberto
Vojnov, Adrián Alberto
Malamud, Florencia

Open link

Publication date

September 2016

DOI

10.15252/embr.201541691

Publisher

EMBO

Journal

EMBO Reports

Abstract

Phytochromes constitute a major photoreceptor family found in plants, algae, fungi, and prokaryotes, including pathogens. Here, we report that Xanthomonas campestris pv. campestris (Xcc), the causal agent of black rot disease which affects cruciferous crops worldwide, codes for a functional bacteriophytochrome (XccBphP). XccBphP possesses an N-terminal PAS2-GAF-PHY photosensory domain triad and a C-terminal PAS9 domain as its output module. Our results show that illumination of Xcc, prior to plant infection, attenuates its virulence in an XccBphP-dependent manner. Moreover, in response to light, XccBphP downregulates xanthan exopolysaccharide production and biofilm formation, two known Xcc virulence factors. Furthermore, the XccbphP null mu...