Rabea Schweiger1,2, Anna-Maria Heise1, Marcus Persicke2, Caroline Müller1,2
1Department of Chemical Ecology,1,2Center for Biotechnology (CeBiTec),
Bielefeld University
Specificity of metabolic plant responses to salicylic and jasmonic acid and impacts on chewing and sucking herbivores
Herbivores
Piercing-sucking
Chewing-biting
Pathway interference metabolic outcome ?
JA-mediated defences
Jasmonic acid (JA)
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Feedback onherbivores?
SA-mediated defences
Salicylic acid (SA)
Theoretical effects of phytohormones on plant chemistry
JA-mediated pathway SA-mediated pathway
JA-specific targets
SA-specific targets
Interaction targets
Common targets
-
SA targets inhibited by JA
JA targets inhibited by
SA
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Theoretical effects of phytohormones on plant chemistry
JA-mediated pathway SA-mediated pathway
JA-specific targets
SA-specific targets
Interaction s
Common targets
-
SA targets inhibited by JA
JA targets inhibited by
SA
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Analyses of leaf AND phloem exudate metabolites
Plantago lanceolata
Daily application of phytohormones Control (0.01% Triton, pH 3.1) JA (0.5 mM) SA (0.5 mM) JA + SA (0.5 mM each) JA + SA (0.25 mM each)
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
JA (0.5 mM)
Effects of phytohormones on leaf / phloem metabolomeafter 72 h (2 treatments)
significance (U test, P < 0.05)
Volcano plots
fold change (<0.5, >2)
Leaves: 1,414 features, phloem: 36 metabolites N = 10; Mann-Whitney U-tests
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
JA (0.5 mM)
SA (0.5 mM)
Phytohormone-specific modulation of metabolic pool sizes
Effects of phytohormones on leaf / phloem metabolomeafter 72 h (2 treatments)
Some overlap in responses
Leaves: 1,414 features, phloem: 36 metabolites N = 10; Mann-Whitney U-tests
Effects of phytohormones on leaf / phloem metabolomeafter 72 h (2 treatments)
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
JA + SA (0.25 mM)
JA + SA (0.5 mM)
• Changes in metabolite pool sizes depend on applied conc.
Leaves: 1,414 features, phloem: 36 metabolites N = 10; Mann-Whitney U-tests
No effects on typical targets (iridoid glycosides)
Effects of phytohormones on leaf / phloem metabolomeafter 72 h (2 treatments with 0.5 mM concentrations)
Increased
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Effects of phytohormones on leaf / phloem metabolomeafter 72 h (2 treatments with 0.5 mM concentrations)
Increased
Decreased
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
• Induction pattern fits to theoretical framework• In phloem exudates mainly down-regulation
-
Effects of phytohormones on leaf / phloem metabolomeafter 72 h (2 treatments with 0.5 mM concentrations)
Down-regulated
Effects on chewing / sucking herbivores
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Daily application of phytohormones 0.5 mM (150 pmol)
Heliothis virescens
Effects of phytohormone-treatmentson survival of chewing herbivore
Kaplan-Meier, log-rank tests + Bonferroni , N = 10
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
X - censoring
• Negative impact of both JA and SA• Attenuation of negative effects when hormones applied simultaneously
Myzus persicae
• Negative impact of JA and SA on herbivores of both feeding types• Intermediate survival on plants treated with both phytohormones
Effects of phytohormone-treatmentson survival of sucking herbivore
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
X - censoring
Kaplan-Meier, log-rank tests + Bonferroni , N = 10
Summary• Responses of Plantago lanceolata are highly treatment-specific
• Complementary, synergistic and antagonistic phytohormone effects fine-tune the plant metabolome
-
• Partial attenuation of effects when hormones applied together → strong interactions between both phytohormone pathways
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
• Herbivores of both feeding types negatively affected by both phytohormones when applied individually → complementary effects of the hormones
Schweiger et al. (2014) Plant Cell Environ 37: 1574-1585
Thanks Chemical Ecology group, Bielefeld University
Karsten Niehaus, CeBiTec, Bielefeld University
Effects of phytohormone-treatmentson population dynamics of aphids
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Start: N = 10 x 10 adults
• negative impact of JA and SA on population growth
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Start: N = 10 x 10 adults
Effects of phytohormone-treatmentson population dynamics of aphids
partial attenuation of negative effects when hormones applied simultaneously
→ No induction of iridoid glycosides
Schweiger, Heise, Persicke, Müller - Chemical Ecology - Bielefeld University, Germany
Kruskal-Wallis test, X² = 8.254, df = 4, P = 0.935, N = 10
Effects of phytohormones on target compoundsafter 72 h (2 treatments)
JA/SA pathway crosstalk
Adapted from Pieterse et al. (2009) Nat Chem Biol