The differential spatial distribution of secondary metabolites in Arabidopsis leaves reacting hypersensitively to Pseudomonas syringae pv. tomato is dependent on the oxidative burst.
Secondary metabolites (SMs) play key roles in pathogen responses, although knowledge of their precise functions is limited by insufficient characterization of their spatial response. The present study addressed this issue in Arabidopsis leaves by non-targeted and targeted metabolite profiling of Pseudomonas syringae pv. tomato (Pst-AvrRpm1) infected and adjacent uninfected leaf tissues. While overlap was observed between infected and uninfected areas, the non-targeted metabolite profiles of these regions differed quantitatively and clustering analysis underscores a differential distribution of SMs within distinct metabolic pathways. Targeted metabolite profiling revealed that infected tissues accumulate more salicylic acid and the characteristic phytoalexin of Arabidopsis, camalexin, than uninfected adjacent areas. On the contrary, the antioxidant coumarin derivative, scopoletin, was induced in infected tissues while its glucoside scopolin predominated in adjacent tissues. To elucidate the still unclear relationship between the accumulation of SMs and reactive oxygen species (ROS) accumulation and signalling, a catalase-deficient line (cat2) in which ROS signalling is up-regulated, was used. Metabolic analysis of cat2 suggests that some SMs have important interactions with ROS in redox homeostasis during the hypersensitive response to Pst-AvrRpm1. Overall, the study demonstrates that ROS availability influences both the amount and the pattern of infection-induced SM accumulation.
Institut de Biologie des Plantes, CNRS-Université Paris-Sud 11, UMR 8618, Bâtiment 630, 91405 Orsay Cedex, France.
Clara
C
Simon
Mathilde
M
Langlois-Meurinne
Floriant
F
Bellvert
Marie
M
Garmier
Laure
L
Didierlaurent
Kamal
K
Massoud
Sejir
S
Chaouch
Arul
A
Marie
Bernard
B
Bodo
Serge
S
Kauffmann
Graham
G
Noctor
Patrick
P
Saindrenan
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D003374:Coumarins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005960:Glucosides / Q000378:metabolism; D007211:Indoles / Q000378:metabolism; D055442:Metabolome; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000472:pathogenicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction; D013844:Thiazoles / Q000378:metabolism; D000094162:Phytoalexins
D003374:Coumarins; D005960:Glucosides; D007211:Indoles; D017382:Reactive Oxygen Species; D020156:Salicylic Acid; D013844:Thiazoles; C102405:camalexin; D000094162:Phytoalexins; C417572:scopolin