Airborne Methyl Jasmonate Research Articles

Airborne Methyl Jasmonate is Metabolized to Jasmonic Acid and 12‐Hydroxyjasmonic Acid, and Induces Jasmonate Biosynthesis in Marchantia polymorpha

AbstractMethyl jasmonate (MeJA) is a volatile jasmonate compound commonly used to induce defense responses in spermatophytes. This study reports that airborne MeJA‐d3, deuterated MeJA, increases the levels of (dinor‐)12‐oxo‐phytodienoic acids [(dn‐)OPDAs] and jasmonic acid (JA) as well as JA‐d3 and 12‐hydroxyjasmonic acid‐d2 (12‐OH‐JA‐d2), MeJA‐d3 metabolites, in the model bryophyte Marchantia polymorpha. Enhancement of JA biosynthesis was substantiated by the expression of JA biosynthetic genes induced by airborne MeJA. Additionally, each of enantiomers, (+)‐MeJA and (−)‐MeJA, was observed to induce the accumulation of JA and (dn‐)OPDAs in M. polymorpha. This study demonstrates that airborne MeJA is metabolized to JA and 12‐OH‐JA, and induces JA biosynthesis in M. polymorpha. Moreover, the transient increase in endogenous JA level after airborne MeJA treatment provides concrete evidence that M. polymorpha biosynthesizes JA.

Ability of plant pathogenic fungi Gibberella fujikuroi and Fusarium commune to react with airborne methyl jasmonate.

The pathogenic fungi Gibberella fujikuroi and Fusarium commune produce jasmonic acid. The application of volatile deuterium-labeled methyl jasmonate increased the amount of nonlabeled JA present in G. fujikuroi and F. commune. These results indicate that the fungi have the ability to react with airborne methyl jasmonate in a manner similar to a plant.

12OHJA, 12OGlcJA, and JA-l-Val as airborne MeJA metabolites

It has been reported that airborne methyl jasmonate (MeJA) was metabolized into jasmonic acid (JA) and jasmonoyl isoleucine (JA-L-Ile). In this report, jasmonoyl valine (JA-L-Val), 12-hydroxy JA (12OHJA), and 12-glucosyloxy JA (12OGlcJA) were identified as metabolites originating from airborne MeJA using tomato (Solanum lycopersicum). Furthermore, the preferable conversion of (-)-MeJA (natural form) into 12OHJA, 12OGlcJA, JA-L-Ile, and JA-L-Val was observed.

Herbivore-induced phenylacetonitrile is biosynthesized from de novo-synthesized l-phenylalanine in the giant knotweed, Fallopia sachalinensis

Plants emit a series of characteristic volatile blends when damaged by insect feeding. Phenylacetonitrile is one of the volatiles from the leaves of the giant knotweed, Fallopia sachalinensis, infested by the Japanese beetle, Popillia japonica, or treated with exogenous airborne methyl jasmonate (MeJA). We examined the precursor of the nitrile and its origin in this system. l-Phenylalanine was determined to be a precursor of the nitrile in F. sachalinensis leaves, and the phenylalanine was also induced by beetle feeding and MeJA treatment. We also found that exogenous MeJA enhanced the biosynthesis of several amino acids in F. sachalinensis leaves.

Interplant communication: Airborne methyl jasmonate is essentially converted into JA and JA-Ile activating jasmonate signaling pathway and VOCs emission

Methyl jasmonate (MeJA) was identified as an airborne signal involved in mediating interplant defense response communications over a decade ago. However, how MeJA activates plant defense systems and what becomes of the compound after it has done so has, thus far, remained unknown. To investigate this, Achyranthes bidentata plants were exposed to deuterated methyl jasmonate (d 2MeJA) followed by absolute quantification of metabolic products of d 2MeJA, and emissions of volatile organic compound (VOC) as defensive markers. We found that d 2MeJA was metabolized mainly into deuterated jasmonic acid (d 2JA) and jasmonoyl isoleucine (d 2JA-Ile), and to a much lesser extent, deuterated jasmonoyl leucine (d 2JA-Leu). Increases in d 2JA-Ile/Leu and also endogenous JA-Ile/Leu were tightly co-related with, and significantly influenced the pattern and amount of, VOC emissions. The amount of accumulated d 2JA-IIe was 13.1-fold higher than d 2JA-Leu, whereas the amounts of JA-IIe and JA-Leu accumulated were almost identical. This study demonstrates that exogenous MeJA activates defensive systems (such as VOC emissions) in receiver plants by essentially converting itself into JA and JA-IIe and initiating a signal transduction leading to VOC emissions and induction of endogenous JA-IIe and JA-Leu, which in turn cause further amplification of VOC emissions.

Airborne Methyl Jasmonate Induces Stilbene Accumulation in Leaves and Berries of Grapevine Plants

The study investigated whether gaseous methyl jasmonate (MeJa) can induce stilbene accumulation and synthesis potential in response to an abiotic stress (ultraviolet light) in grapevine leaves and berries. It was found that a very low level of atmospheric MeJa (400 nmol/L) can increase stilbene contents in these two organs, although response to MeJa is different between leaves and berries. In leaves MeJa mainly enhances <i>trans</i>-piceid accumulation, while in berries it stimulates <i>trans</i>-resveratrol synthesis. Moreover, during ripening, berries rapidly lose their capacity to respond to MeJa while leaves conserve it. It was also demonstrated that MeJa pretreatment is able to trigger stilbene synthesis potential in response to ultraviolet light, particularly in leaves.

Molecular interactions between the specialist herbivore Manduca sexta (Lepidoptera, Sphingidae) and its natural host Nicotiana attenuata. I. Large-scale changes in the accumulation of growth- and defense-related plant mRNAs.

Plants respond to herbivore attack with a dramatic functional reorganization that involves the activation of direct and indirect defenses and tolerance, which in turn make large demands on primary metabolism. Here we provide the first characterization of the transcriptional reorganization that occurs after insect attack in a model plant-herbivore system: Nicotiana attenuata Torr. ex Wats.-Manduca sexta. We used mRNA differential display to characterize one-twentieth of the insect-responsive transcriptome of N. attenuata and verified differential expression for 27 cDNAs. Northern analyses were used to study the effects of folivory and exposure to airborne methyl jasmonate and for kinetic analyses throughout a 16-h- light/8-h-dark cycle. Sequence similarity searches allowed putative functions to be assigned to 15 transcripts. Genes were related to photosynthesis, electron transport, cytoskeleton, carbon and nitrogen metabolism, signaling, and a group responding to stress, wounding, or invasion of pathogens. Overall, transcripts involved in photosynthesis were strongly down-regulated, whereas those responding to stress, wounding, and pathogens and involved in shifting carbon and nitrogen to defense were strongly up-regulated. The majority of transcripts responded similarly to airborne methyl jasmonate and folivory, and had tissue- and diurnal-specific patterns of expression. Transcripts encoding Thr deaminase (TD) and a putative retrotransposon were absent in control plants, but were strongly induced after herbivory. Full-length sequences were obtained for TD and the pathogen-inducible alpha-dioxygenase, PIOX. Effects of abiotic and biotic stimuli were investigated for transcripts encoding TD, importin alpha, PIOX, and a GAL83-like kinase cofactor.

Induction of chalcone synthase expression in white spruce by wounding and jasmonate.

The phenylpropanoid pathway has important functions in angiospermous plants following exposure to environmental stresses, such as wounding and pathogen attack, that lead to production of compounds including lignin, flavonoids and phytoalexins. Chalcone synthase (CHS) is a key enzyme in this pathway, catalyzing the first step in flavonoid biosynthesis, whose expression can be induced in response to environmental stress. To explore the response of conifers to environmental stress, expression of spruce CHS and its inducibility were investigated. A partial spruce CHS cDNA clone was isolated using PCR. Examination of the expression patterns of the CHS gene family in white spruce revealed accumulation of CHS mRNA in needle tissue following mechanical wounding, or application of signal molecules like jasmonic acid or methyl jasmonate. Repeated mechanical wounding or jasmonate applications had an enhancing effect on transcript accumulation in needles. A systemic accumulation of CHS mRNAs following wounding was also observed. Conifers thus appear to possess a general wound response similar to that found for angiosperms, which includes CHS induction as well as its inducibility by jasmonic acid and airborne methyl jasmonate.

Interactions of airborne methyl jasmonate with vegetative storage protein gene and protein accumulation and biomass partitioning inPopulusplants

In young poplar (Populus nigra Muench × Populus maximowiczii A. Henry) plants, vegetative storage proteins (VSPs), the bark storage protein (BSP), and (or) wound-inducible 4 protein (WIN4) mRNAs were present in the apical and basal leaves and in the basal leaves, respectively. VSPs accumulated in the apical leaves and to a lesser extent in the stem. The response of the plants to 20 µM airborne methyl jasmonate (MJ) was examined in four parts ( apical and basal leaves, stem, and roots) in both short-term (within 72 h) and long-term (1, 2, 3, and 4 weeks) experiments. In the short-term, MJ-treated plants either induced or increased the part-specific expression of win4 and bsp, and accumulation of BSP and (or) WIN4. In the long-term, MJ treatment resulted in part-specific alterations in protein and nitrogen concentration and further altered BSP and WIN4 accumulation. The MJ-treated plants increased both the biomass allocation to the stem, without a change in the relative growth rate, and the tolerance low temperature (-2°C). Together, these results suggest the BSP and WIN4 are both involved in short-term N cycling and that exogenous MJ treatment promotes changes in nitrogen metabolism in poplar.

Interactions of airborne methyl jasmonate with vegetative storage protein gene and protein accumulation and biomass partitioning in &lt;i&gt;Populus&lt;/i&gt; plants

In young poplar (Populus nigra Muench × Populus maximowiczii A. Henry) plants, vegetative storage proteins (VSPs), the bark storage protein (BSP), and (or) wound-inducible 4 protein (WIN4) mRNAs were present in the apical and basal leaves and in the basal leaves, respectively. VSPs accumulated in the apical leaves and to a lesser extent in the stem. The response of the plants to 20 µM airborne methyl jasmonate (MJ) was examined in four parts ( apical and basal leaves, stem, and roots) in both short-term (within 72 h) and long-term (1, 2, 3, and 4 weeks) experiments. In the short-term, MJ-treated plants either induced or increased the part-specific expression of win4 and bsp, and accumulation of BSP and (or) WIN4. In the long-term, MJ treatment resulted in part-specific alterations in protein and nitrogen concentration and further altered BSP and WIN4 accumulation. The MJ-treated plants increased both the biomass allocation to the stem, without a change in the relative growth rate, and the tolerance low te...

Enhanced Degreening of Apple Fruit by Jasmonates

Airborne methyl jasmonate (MJ) can modulate apple fruit ripening, including the degreening process. Degreening of `Fuji' and `Golden Delicious' apples by jasmonates [jasmonic acid (JA) and MJ] in aqueous solution was investigated. JA and MJ applied by dipping apples in solutions of jasmonates for 2 min enhanced degreening during ripening at 20C. MJ was more effective at promoting degreening compared to JA. The minimum concentration of jasmonates required to promote significant degreening during the 2-week ripening period was 1 mM. Degreening of jasmonate-treated apples ripened at 4C progressed slower compared to apples ripened at 20°C. JA stimulated apple fruit ethylene production at concentrations as low as 10 μM. Jasmonates at 1 or 10 mM were more effective at accelerating the degreening process compared to 0.35 or 3.5 mM ethephon. Firmness, soluble solids content, and titratable acidity of `Fuji' apples were not significantly affected by jasmonate treatments. Peel injury occurred on apples treated with 10 mM JA or 3.5 mM ethephon.

Airborne methyl jasmonate stimulates the biosynthesis of furanocoumarins in the leaves of celery plants (Apium graveolens)

When leaves ofApium graveolens are exposed to vapours of methyl jasmonate (MeJa) or fed through the petiole with aqueous solutions of jasmonic acid (Ja), the levels of natural furanocoumarins, in particular xanthotoxin and bergapten, are greatly increased. The induction becomes manifest after application of ≥20 nmol of either Meja or Ja. Levels of xanthotoxin and bergapten begin to increase approximately 24 h after application of the inducer. Maximum concentration of the two furanocoumarins (40–70 fold increase) is reached after 4–6 days. This pronounced effect of volatile MeJa on the physiological status of the celery leaf may be considered as representative of a build-up of chemical defenses, in an undamaged plant, after receipt of airborne signals from damaged or undamaged, but fragrant plants.

Expansion of potato cells in response to jasmonic acid

Since jasmonic acid (JA) has strong potato tuber-inducing activity and tuberization of potato plants is initiated mainly by expansion of cells, it is highly likely that JA is capable of inducing expansion of potato cells. When disks cut from potato tubers were cultured on medium that contained JA, the disks began to swell markedly after 1 day in culture. Within 5 days in culture, the fresh weight of the disks doubled in the presence of JA at 3 × 10 −5 M. Light microscopy revealed that the swelling was due to the expansion and not the division of cells. JA exhibited this expansion-inducing activity at concentrations above 10 −5 M. Air-borne methyl jasmonate (JA-Me) also exhibited this activity. The cells that expanded in response to JA in the medium or to airborne JA-Me were localized on the lower side of each disk. The localization seemed to be a result of the greater availability of water. Sucrose in the culture medium was not necessary for the expansion of cells. The expansion-inducing activity appeared to be specific to JA and related compounds, since various plant hormones and a precursor of ethylene had no appreciable effects on the size of cells. Abscisic acid at concentrations above 10 −5 M and benzyl adenine at concentrations above 10 −4 M markedly inhibited the JA-induced expansion of cells. The expansion-inducing activities of JA and JA-Me seem to be associated with their tuber-inducing activities.

Regulation of Expression of Proteinase Inhibitor Genes by Methyl Jasmonate and Jasmonic Acid

Gel electrophoretic analysis of the proteinase inhibitor proteins induced in tomato leaves by airborne methyl jasmonate (EE Farmer, CA Ryan [1990] Proc Natl Acad Sci USA 87: 7713-7716) revealed the new appearance of inhibitors I and II and two other, higher molecular mass proteins (63.5 and 87 kilodaltons). Northern analysis of methyl jasmonate-induced inhibitors I and II mRNAs in tomato (Lycopersicon esculentum) leaves, and of alfalfa trypsin inhibitor (a Bowman-Birk family inhibitor) mRNA in alfalfa (Medicago sativa) leaves, indicated that nascent inhibitor mRNAs were regulated in a manner similar to wounding, that is, at the transcriptional level. In tobacco (Nicotiana tabacum), transformed with a fused gene composed of the 5' and 3' regions of a wound-inducible potato inhibitor II and a chloramphenicol acetyl transferase (CAT) gene coding region, CAT activity was induced in leaves by methyl jasmonate, consistent with a transcriptional regulation of the inhibitor II gene. In tomato leaves, inhibitor I and II mRNAs and proteins accumulated in leaves distal to those exposed to methyl jasmonate or jasmonic acid to similar levels as in exposed leaves. We suggest that in response to wound signals generated by insect or pathogen attacks, linolenic acid is released into the cytoplasm from plant cell membrane lipids and is rapidly converted in cells to jasmonic acid (or perhaps a closely related derivative such as methyl jasmonate), which serves as a signal to regulate the expression of proteinase inhibitor genes.

Interplant communication: airborne methyl jasmonate induces synthesis of proteinase inhibitors in plant leaves.

Inducible defensive responses in plants are known to be activated locally and systemically by signaling molecules that are produced at sites of pathogen or insect attacks, but only one chemical signal, ethylene, is known to travel through the atmosphere to activate plant defensive genes. Methyl jasmonate, a common plant secondary compound, when applied to surfaces of tomato plants, induces the synthesis of defensive proteinase inhibitor proteins in the treated plants and in nearby plants as well. The presence of methyl jasmonate in the atmosphere of chambers containing plants from three species of two families, Solanaceae and Fabaceae, results in the accumulation of proteinase inhibitors in leaves of all three species. When sagebrush, Artemisia tridentata, a plant shown to possess methyl jasmonate in leaf surface structures, is incubated in chambers with tomato plants, proteinase inhibitor accumulation is induced in the tomato leaves, demonstrating that interplant communication can occur from leaves of one species of plant to leaves of another species to activate the expression of defensive genes.