Shedding light on the role of photosynthesis in pathogen colonization and host defense.
The role of photosynthesis in plant defense is a fundamental question awaiting further molecular and physiological elucidation. To this end we investigated host responses to infection with the bacterial pathogen Xanthomonas axonopodis pv. citri, the pathogen responsible for citrus canker. This pathogen encodes a plant-like natriuretic peptide (XacPNP) that is expressed specifically during the infection process and prevents deterioration of the physiological condition of the infected tissue. Proteomic assays of citrus leaves infected with a XacPNP deletion mutant (DeltaXacPNP) resulted in a major reduction in photosynthetic proteins such as Rubisco, Rubisco activase and ATP synthase as a compared with infection with wild type bacteria. In contrast, infiltration of citrus leaves with recombinant XacPNP caused an increase in these host proteins and a concomitant increase in photosynthetic efficiency as measured by chlorophyll fluorescence assays. Reversion of the reduction in photosynthetic efficiency in citrus leaves infected with DeltaXacPNP was achieved by the application of XacPNP or Citrus sinensis PNP lending support to a case of molecular mimicry. Finally, given that DeltaXacPNP infection is less successful than infection with the wild type, it appears that reducing photosynthesis is an effective plant defense mechanism against biotrophic pathogens.
Garavaglia
Betiana S
BS
Thomas
Ludivine
L
Gottig
Natalia
N
Zimaro
Tamara
T
Garofalo
Cecilia G
CG
Gehring
Chris
C
Ottado
Jorgelina
J
Proteomics. 2005 Jan;5(1):212-21
15593128
BMC Plant Biol. 2010 Mar 21;10:51
20302677
Cell Mol Life Sci. 1998 Mar;54(3):272-6
9575339
Plant Cell Physiol. 2004 Aug;45(8):1093-8
15356335
BMC Plant Biol. 2008 Feb 29;8:24
18307823
Int J Biochem Cell Biol. 2003 Sep;35(9):1318-22
12798346
Proc Natl Acad Sci U S A. 2008 Nov 25;105(47):18631-6
19015524
J Exp Bot. 2003 Jun;54(387):1553-64
12730261
Mol Cell Biol Res Commun. 1999 Jul;2(1):53-7
10527892
FEBS Lett. 2004 Jan 2;556(1-3):99-103
14706834
PLoS One. 2010 Jan 28;5(1):e8950
20126632
BMC Evol Biol. 2004 Mar 24;4:10
15038836
Commun Integr Biol. 2009;2(2):89-90
19704897
Mol Plant Microbe Interact. 2009 May;22(5):487-97
19348567
J Exp Bot. 2007;58(15-16):4019-26
18182420