cis-Jasmone

Proceedings of the National Academy of Sciences of the United States of America, 01 Aug 2000, 97(16):9329-9334

New roles for cis-jasmone as an insect semiochemical and in plant defense.[Pubmed: 10900270 ]

cis-Jasmone, or (Z)-jasmone, is well known as a component of plant volatiles, and its release can be induced by damage, for example during insect herbivory.
METHODS AND RESULTS:
Using the olfactory system of the lettuce aphid to investigate volatiles from plants avoided by this insect, (Z)-jasmone was found to be electrophysiologically active and also to be repellent in laboratory choice tests. In field studies, repellency from traps was demonstrated for the damson-hop aphid, and with cereal aphids numbers were reduced in plots of winter wheat treated with (Z)-jasmone. In contrast, attractant activity was found in laboratory and wind tunnel tests for insects acting antagonistically to aphids, namely the seven-spot ladybird and an aphid parasitoid. When applied in the vapor phase to intact bean plants, (Z)-jasmone induced the production of volatile compounds, including the monoterpene (E)-beta-ocimene, which affect plant defense, for example by stimulating the activity of parasitic insects. These plants were more attractive to the aphid parasitoid in the wind tunnel when tested 48 h after exposure to (Z)-jasmone had ceased.
CONCLUSIONS:
This possible signaling role of (Z)-jasmone is qualitatively different from that of the biosynthetically related methyl jasmonate and gives a long-lasting effect after removal of the stimulus. Differential display was used to compare mRNA populations in bean leaves exposed to the vapor of (Z)-jasmone and methyl jasmonate. One differentially displayed fragment was cloned and shown by Northern blotting to be up-regulated in leaf tissue by (Z)-jasmone. This sequence was identified by homology as being derived from a gene encoding an alpha-tubulin isoform.

Birkett M A , Campbell C A M , Chamberlain K , et al. New roles for cis-jasmone as an insect semiochemical and in plant defense[J]. Proceedings of the National Academy of ences of the United States of

cis-Jasmone induces Arabidopsis genes that affect the chemical ecology of multitrophic interactions with aphids and their parasitoids[Pubmed: 18356298]

It is of adaptive value for a plant to prepare its defenses when a threat is detected, and certain plant volatiles associated with insect damage, such as cis-Jasmone (CJ), are known to switch-on defense metabolism.
METHODS AND RESULTS:
We used aphid and aphid parasitoid responses to Arabidopsis thaliana as a model system for studying gene expression and defense chemistry and its impact at different trophic levels. Differential responses to volatiles of induced Arabidopsis occurred for specialist and generalist insects: the generalist aphid, Myzus persicae, was repelled, whereas the specialist, Lipaphis erysimi, was attracted; the generalist aphid parasitoid Aphidius ervi was attracted, but the specialist parasitoid Diaeretiella rapae was not affected. A. ervi also spent longer foraging on induced plants than on untreated ones. Transcriptomic analyses of CJ-induced Arabidopsis plants revealed that a limited number of genes, including a gene for a cytochrome P450, CYP81D11, were strongly up-regulated in the treated plants.
CONCLUSIONS:
We examined transgenic Arabidopsis lines constitutively overexpressing this gene in bioassays and found insect responses similar to those obtained for wild-type plants induced with CJ, indicating the importance of this gene in the CJ-activated defense response. Genes involved in glucosinolate biosynthesis and catabolism are unaffected by CJ and, because these genes relate to interactions with herbivores and parasitoids specific to this family of plants (Brassicaceae), this finding may explain the differences in behavioral response of specialist and generalist insects.

Planta,2010,232:1163–1180.

The transcriptome of cis-jasmone-induced resistance in Arabidopsis thaliana and its role in indirect defence.[Reference: WebLink]

cis-Jasmone (CJ) is a plant-derived chemical that enhances direct and indirect plant defence against herbivorous insects. To study the signalling pathway behind this defence response, we performed microarray-based transcriptome analysis of CJ-treated Arabidopsis plants.
METHODS AND RESULTS:
CJ influenced a different set of genes from the structurally related oxylipin methyl jasmonate (MeJA), suggesting that CJ triggers a distinct signalling pathway. CJ is postulated to be biosynthetically derived from jasmonic acid, which can boost its own production through transcriptional up-regulation of the octadecanoid biosynthesis genes LOX2,AOS and OPR3. However, no effect on these genes was detected by treatment with CJ. Furthermore, CJ-responsive genes were not affected by mutations in COI1 or JAR1, which are critical signalling components in MeJA response pathway. Conversely, a significant proportion of CJ-inducible genes required the three transcription factors TGA2, TGA5 and TGA6, as well as the GRAS regulatory protein SCARECROW-like 14 (SCL14), indicating regulation by a different pathway from the classical MeJA response. Moreover, the biological importance was demonstrated in that mutations in TGA2, 5, 6, SCL14 and the CJ-inducible gene CYP81D11 blocked CJ-induced attraction of the aphid parasitoid Aphidius ervi, demonstrating that these components play a key role in CJ-induced indirect defence.
CONCLUSIONS:
Collectively, our results identify CJ as a member of the jasmonates that controls indirect plant defence through a distinct signalling pathway.