Effects of feeding Spodoptera littoralis on lima bean leaves: IV. Diurnal and nocturnal damage differentially initiate plant volatile emission.
Continuous mechanical damage initiates the rhythmic emission of volatiles in lima bean (Phaseolus lunatus) leaves; the emission resembles that induced by herbivore damage. The effect of diurnal versus nocturnal damage on the initiation of plant defense responses was investigated using MecWorm, a robotic device designed to reproduce tissue damage caused by herbivore attack. Lima bean leaves that were damaged by MecWorm during the photophase emitted maximal levels of beta-ocimene and (Z)-3-hexenyl acetate in the late photophase. Leaves damaged during the dark phase responded with the nocturnal emission of (Z)-3-hexenyl acetate, but with only low amounts of beta-ocimene; this emission was followed by an emission burst directly after the onset of light. In the presence of (13)CO(2), this light-dependent synthesis of beta-ocimene resulted in incorporation of 75% to 85% of (13)C, demonstrating that biosynthesis of beta-ocimene is almost exclusively fueled by the photosynthetic fixation of CO(2) along the plastidial 2-C-methyl-D-erythritol 4-P pathway. Jasmonic acid (JA) accumulated locally in direct response to the damage and led to immediate up-regulation of the P. lunatus beta-ocimene synthase gene (PlOS) independent of the phase, that is, light or dark. Nocturnal damage caused significantly higher concentrations of JA (approximately 2-3 times) along with enhanced expression levels of PlOS. Transgenic Arabidopsis thaliana transformed with PlOS promoter :: beta-glucuronidase fusion constructs confirmed expression of the enzyme at the wounded sites. In summary, damage-dependent JA levels directly control the expression level of PlOS, regardless of light or dark conditions, and photosynthesis is the major source for the early precursors of the 2-C-methyl-D-erythritol 4-P pathway.
Arimura
Gen-ichiro
G
Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany.
Köpke
Sabrina
S
Kunert
Maritta
M
Volpe
Veronica
V
David
Anja
A
Brand
Peter
P
Dabrowska
Paulina
P
Maffei
Massimo E
ME
Boland
Wilhelm
W
D000085:Acetates / Q000378:metabolism; D000080462:Acyclic Monoterpenes; D000475:Alkenes / Q000378:metabolism*; D000818:Animals; D002247:Carbon Isotopes / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology; D003517:Cyclopentanes / Q000378:metabolism; D004896:Erythritol / Q000031:analogs & derivatives / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006790:Host-Parasite Interactions / Q000502:physiology*; D007814:Larva / Q000502:physiology; D008027:Light; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000378:metabolism; D027805:Phaseolus / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D018411:Spodoptera / Q000502:physiology*; D013403:Sugar Phosphates / Q000378:metabolism; D015854:Up-Regulation; D014835:Volatilization
C114232:2-C-methylerythritol 4-phosphate; D000085:Acetates; D000080462:Acyclic Monoterpenes; D000475:Alkenes; D002247:Carbon Isotopes; D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D013403:Sugar Phosphates; C443996:beta-ocimene; C425828:3-hexenylacetate; C011006:jasmonic acid; D004896:Erythritol