Herbivore-Induced Plant Volatiles:
Plant Defence Against Herbivory
May 10, 2012
Darija Muharemagic
Supervisor: Maxim Berezovski
Outline
• Introduction to plant volatiles
– Biosynthetic pathways
– Functions
• Plant defence
– Stimuli
– Jasmonate signalling
• Integrated pest management
– Synthesis of methyl jasmonate
• Conclusion
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Fight-or-flight response
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Plant volatiles
• Volatile organic compounds
released by plants
– 1000 tera-grams of carbon
per year for terpenoids
– e.g. essential oil in rose
petals ~0.02–0.03% of plant’s
weight
Qualley, A. and Dudareva, N. 2010. Plant Volatiles. eLS.
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Plant volatiles
• Complex variety of volatile chemicals
– Essential oils, etheral oils or essences
• Numerous organic structures
– Saturated and unsaturated hydrocarbons
– Esters, aldehydes, ketones and amines
• Secondary metabolites
– No assigned role in growth, development or
reproduction
• Numerous functions
– In plants
– For mankind
Qualley, A. and Dudareva, N. 2010. Plant Volatiles. eLS.
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Network of interactions
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Categories of PVOCs
Sulfides, indoles and amines
Aliphatics and aromatics
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Volatile sulfides, indoles and amines
• Garlic-released volatile
• Allicin
– Antimicrobial, insecticide
– Inhibit blood clotting and lower blood pressure
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Volatile aliphatics and aromatics
• Great esthetical and commercial importance
– Distinctive odours associated with fruits and flowers
• Primary ecological function as pollinator
attractants in flowers
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Biosynthesis of plant volatiles:
Amino acid-derived volatiles
• Catabolism of branched chain amino acids gives rise to
constituents of banana, apple, strawberry and tomato
aromas.
Kochevenko, A., Araújo, W.L., Maloney, G.S., Tieman, D.M., Do, P.T., Taylor, M.G., Klee, H.J. & Fernie, A.R Mol Plant. 2012
Mar;5(2):366-75. Epub 2011
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Biosynthesis of plant volatiles:
Terpenes
• Responsible for several characteristic odours
– Citrus, mint and conifers
• Nonspecific toxins
– Plant pathogens
– Insects
– Growth inhibition of competing plants
• Formed by two or more isoprenes
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Biosynthesis of plant volatiles:
Isoprenes (terpene building blocks)
Roberts SC. Nature Chemical Biology 3, 387 - 395 (2007)
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Biosynthesis of plant volatiles:
Fatty acid-derived plant volatiles
• Originate from C18 unsaturated fatty acids
Hans Weber. Trends in plant science. Volume 7, Issue 5, 1 May 2002, Pages 217-224
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Biosynthesis of plant volatiles:
Phenylpropanoids
Qualley AV, Dudareva N, Methods Mol Bio. 2009;553:329-43
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Plant volatiles
• Generalized pathways for the synthesis of plant
volatiles
– Deterring predators and attracting pollinators
Qualley, A. and Dudareva, N. 2010. Plant Volatiles. eLS.
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Pollinators and volatiles
• Plant emits volatiles to attract
pollinators
• Orchid Ophrys sphegodes
– Solitary bee species Andrena
nigroaenea
– Flower mimics appearance and
odours of a female bee
– After pollination, compounds of
non-receptive bees
F.P Schiestl, M Ayasse, H.F Paulus, C Lofstedt, B.S Hansson, F Ibarra, W Francke, Nature, 399 (1999), pp. 421–422
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Plant defences
• Constitutive defence
– Physical and chemical barriers
• Peptides, cellulose, lignin, cuticular waxes, toxins
• Induced defence
– Up-regulation of constitutively synthesized
compounds
– De novo compound synthesis
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Response induction by herbivores
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‘Cry for help’
• >25 predator species are known to be attracted to
HIPVs
• Herbivorous attack
– Induction of volatiles
– Attraction of carnivorous insects that prey on herbivores
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Response induction
‘If you know your enemies and know yourself, you can win a hundred
battles without a single loss’
Sun Tzu, The Art of War
Volatile emission stimuli
Mechanical
Oral
secretion
Oviposition
Walking
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Response induction: Mechanical
• Effect on lima bean leaves
• MecWorm for mechanical treatment of leaves
• Comparison of 4 volatiles from
different biosynthetic pathways
– Varying time of treatment
– Varying area of damage
• Pattern wheel and razor blade did not induce
any substantial volatile emission
Mithöfer, A., Wanner, G. & Boland, W. Plant Physiology 137 (3): 1160–8
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Response induction: Mechanical
Time (h) and area
(mm2) treated
2.9 hours
313 mm2
Mithöfer, A., Wanner, G. & Boland, W. 2005, Plant Physiology 137 (3): 1160–8
16 hours
313 mm2
16 hours
733 mm2
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Response induction: Oviposition
• Spotted stemborer, a major pest of maize
• Volatiles induced by oviposition
– Attraction of egg and larval parasitoids
Tamiru, A., Bruce, T.J.A., Woodcock, C.M., Caulfield, J.C., Midega, C.A.O., Ogol, C.K.P.O., Mayon, P., Birkett, M.A., Pickett, J.A. & Khan,
Z.R. , Ecology Letters, (2011) 14: 1075–1083
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Response induction: Oviposition
• Attraction of egg and larval parasitoids
– Leaves with egg deposition
– Leaves from the same plant without egg deposition
– Treatment with adhesive substance underneath eggs
• Attraction of parasitoids to DMNT and TMTT, as
well as caryophyllene at higher doses
Tamiru, A., Bruce, T.J.A., Woodcock, C.M., Caulfield, J.C., Midega, C.A.O., Ogol, C.K.P.O., Mayon, P., Birkett, M.A., Pickett, J.A. & Khan,
Z.R. , Ecology Letters, (2011) 14: 1075–1083
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Jasmonate pathway
• Biosynthesis of jasmonic acid
Schaller F, SchallerA,Stintzi A Biosynthesis and Metabolism of Jasmonates J Plant Growth Regul (2005) 23:179–199
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Jasmonate pathway:
wound response
• Proteinase inhibitors
– Insects: proteolytic digestion of proteins
– Defence against proteolytic enzymes
• Localized cell death
– Defence against biotic challenges
– Limiting spread of infection
• Jasmonate-derived compounds
– Defence against herbivory
– Plant communication
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Jasmonate-Isoleucine
• JA activation upon specific conjugation to isoleucine
• JA metabolite with known molecular mechanism of action
• JA-Ile functions by relieving repression of genes involved
in jasmonate response
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Reception of JA-Ile
• Jasmonate ZIM domain (JAZ) protein represses
transcription of jasmonate-response genes by binding to
MYC2 transcription factor
Pauwels, L. & Goossens, A. 2011, Plant Cell, vol. 23, no. 9, pp. 3089-3100.
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Reception of JA-Ile
• Jasmonate-isoleucine recruits JAZ to SCFCOI1 complex
Pauwels, L. & Goossens, A. 2011, Plant Cell, vol. 23, no. 9, pp. 3089-3100.
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Reception of JA-Ile
• Poly-ubiquitylation in presence of JA-Ile
Pauwels, L. & Goossens, A. 2011, Plant Cell, vol. 23, no. 9, pp. 3089-3100.
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Reception of JA-Ile
• Poly-ubiquitylated JAZ
• Degradation
• Results in expression of jasmonate-responsive genes
Pauwels, L. & Goossens, A. 2011, Plant Cell, vol. 23, no. 9, pp. 3089-3100.
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Methyl Jasmonate (MeJA)
• Volatile JA derivative
• Induces synthesis of protease inhibitors
• Induces accumulation of other chemicals
involved in plant defence
– Sagebrush releases MeJA
• Tomato plants in proximity synthesize PIs
• Potential in pest management
– Low concentrations
Farmer, E.E. & Ryan, C.A. 1990, Proceedings of the National Academy of Sciences of the United States of America, vol. 87, no. 19,
pp. 7717-77
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Integrated pest management
• Persimmon trees infested by Japanese wax scales
• Ladybeetle is a natural predator of Japanese wax
scales
• Persimmon trees produce volatiles induced by
MeJA
Zhang, Y., Xie, Y., Xue, J., Peng, G. & Wang, X. 2009, Environmental Entomol
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Integrated pest management
• Tested ladybeetle attraction to different groups
– Scale-infested group
– MeJA-treated group
• Ladybeetle response similar for scale-infested
and MeJA-treated groups
• Total of 23 volatile chemical compounds
detected in these groups (9 terpenoids, α-pinene
being the most abundant)
Zhang, Y., Xie, Y., Xue, J., Peng, G. & Wang, X. 2009, Environmental Entomol
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Total synthesis of methyl jasmonate
• (-)-Methyl jasmonate
– Stereogenic centers
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Synthesis of methyl jasmonate
• 83% ee
• Ethyl and isopropyl substituents on the ligand
gave the best enantioselectivity
TAKEDA, H., WATANABE, H. and NAKADA, M., 2006. Tetrahedron, 62(34), pp. 8054-8063.
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Synthesis of methyl jasmonate
TAKEDA, H., WATANABE, H. and NAKADA, M., 2006. Tetrahedron, 62(34), pp. 8054-8063.
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Conclusion
• Plants use sophisticated mechanisms to
overcome stresses
• Production of volatile organic compounds
– Various metabolic pathways
– Array of chemical structures
• Protection against herbivores
– Jasmonate and its derivatives
– Integrated pest management
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Acknowledgements
Berezovski Lab
Special thank you to Dr. Durst and
Christine Choueiri
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Thank you!
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