TY - JOUR
T1 - Chloroplasts play a central role in plant defence and are targeted by pathogen effectors
AU - Zabala, Marta de Torres
AU - Littlejohn, George
AU - Jayaraman, Siddharth
AU - Studholme, David
AU - Bailey, Trevor
AU - Lawson, Tracy
AU - Tillich, Michael
AU - Licht, Dirk
AU - Bölter, Bettina
AU - Delfino, Laura
AU - Truman, William
AU - Mansfield, John
AU - Smirnoff, Nicholas
AU - Grant, Murray
N1 - Funding Information:
This work was funded by BBSRC grants BB/E010334/1 to M.G. and BB/F005903/1 to M.G. and N.S. M.T. and D.L. thank R. Bock and the Max Planck Society (MPG) for their support. We are indebted to members of the PRESTA consortium for their efforts in generating the microarray data. We thank J. Greenberg for the Pma4326 hopI1 strain and E. Lopez-Solanilla for the HopN1 derivatives. We are indebted to K. Polanski for generating the images for Fig. 1b and Alan Collmer for Pf55, CUCPB6032 and ΔfliC strains.
Publisher Copyright:
© 2015 Macmillan Publishers Limited. All rights reserved.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - Microbe associated molecular pattern (MAMP) receptors in plants recognize MAMPs and activate basal defences; however a complete understanding of the molecular and physiological mechanisms conferring immunity remains elusive. Pathogens suppress active defence in plants through the combined action of effector proteins. Here we show that the chloroplast is a key component of early immune responses. MAMP perception triggers the rapid, large-scale suppression of nuclear encoded chloroplast-targeted genes (NECGs). Virulent Pseudomonas syringae effectors reprogramme NECG expression in Arabidopsis, target the chloroplast and inhibit photosynthetic CO2 assimilation through disruption of photosystem II. This activity prevents a chloroplastic reactive oxygen burst. These physiological changes precede bacterial multiplication and coincide with pathogen-induced abscisic acid (ABA) accumulation. MAMP pretreatment protects chloroplasts from effector manipulation, whereas application of ABA or the inhibitor of photosynthetic electron transport, DCMU, abolishes the MAMP-induced chloroplastic reactive oxygen burst, and enhances growth of a P. syringae hrpA mutant that fails to secrete effectors.
AB - Microbe associated molecular pattern (MAMP) receptors in plants recognize MAMPs and activate basal defences; however a complete understanding of the molecular and physiological mechanisms conferring immunity remains elusive. Pathogens suppress active defence in plants through the combined action of effector proteins. Here we show that the chloroplast is a key component of early immune responses. MAMP perception triggers the rapid, large-scale suppression of nuclear encoded chloroplast-targeted genes (NECGs). Virulent Pseudomonas syringae effectors reprogramme NECG expression in Arabidopsis, target the chloroplast and inhibit photosynthetic CO2 assimilation through disruption of photosystem II. This activity prevents a chloroplastic reactive oxygen burst. These physiological changes precede bacterial multiplication and coincide with pathogen-induced abscisic acid (ABA) accumulation. MAMP pretreatment protects chloroplasts from effector manipulation, whereas application of ABA or the inhibitor of photosynthetic electron transport, DCMU, abolishes the MAMP-induced chloroplastic reactive oxygen burst, and enhances growth of a P. syringae hrpA mutant that fails to secrete effectors.
UR - http://www.scopus.com/inward/record.url?scp=84958852350&partnerID=8YFLogxK
U2 - 10.1038/NPLANTS.2015.74
DO - 10.1038/NPLANTS.2015.74
M3 - Article
AN - SCOPUS:84958852350
SN - 2055-026X
VL - 1
JO - Nature Plants
JF - Nature Plants
IS - 6
M1 - 15074
ER -