The Experts below are selected from a list of 141 Experts worldwide ranked by ideXlab platform
Naoki Mori - One of the best experts on this subject based on the ideXlab platform.
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N-(18-hydroxylinolenoyl)-L-glutamine: a newly discovered analog of Volicitin in Manduca sexta and its elicitor activity in plants.
Journal of chemical ecology, 2014Co-Authors: Naoko Yoshinaga, Takako Aboshi, Chihiro Ishikawa, James H. Tumlinson, Irmgard H. Seidl-adams, Elizabeth James Bosak, Naoki MoriAbstract:Plants attacked by insect herbivores release a blend of volatile organic compounds (VOCs) that serve as chemical cues for host location by parasitic wasps, natural enemies of the herbivores. Volicitin, N-(17-hydroxylinolenoyl)-l-glutamine, is one of the most active VOC elicitors found in herbivore regurgitants. Our previous study revealed that hydroxylation on the 17th position of the linolenic acid moiety of N-linolenoyl-l-glutamine increases by more than three times the elicitor activity in corn plants. Here, we identified N-(18-hydroxylinolenoyl)-l-glutamine (18OH-Volicitin) from larval gut contents of tobacco hornworm (THW), Manduca sexta. Eggplant and tobacco, two solanaceous host plants of THW larvae, and corn, a non-host plant, responded differently to this new elicitor. Eggplant and tobacco seedlings emitted twice the amount of VOCs when 18OH-Volicitin was applied to damaged leaf surfaces compared to N-linolenoyl-l-glutamine, while both these fatty acid amino acid conjugates (FACs) elicited a similar response in corn seedlings. In both solanaceous plants, there was no significant difference in the elicitor activity of 17OH- and 18OH-Volicitin. Interestingly, other lepidopteran species that have 17OH-type Volicitin also attack solanaceous plants. These data suggest that plants have developed herbivory-detection systems customized to their herbivorous enemies.
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function and evolutionary diversity of fatty acid amino acid conjugates in insects
Journal of Plant Interactions, 2011Co-Authors: Naoki Mori, Naoko YoshinagaAbstract:Abstract Some plants recognize herbivore attack and distinguish it from mechanical wounding because of the chemical components in caterpillar regurgitants. Volicitin and its related compounds, collectively called fatty acid amino acids conjugates (FACs), are such elicitors that function as key compounds to trigger volatile emissions in several plants and ironically help foraging parasitoids. But we do not know if the chemical structural differences of FACs in caterpillars can explain the complicated plant responses which sometimes vary depending on the caterpillar species. It is even unclear why caterpillars make a variety of FACs. Previously, we proposed a hypothesis that FACs might be an intermediate that enhance nitrogen assimilation in insects. Also we reported a broad range of lepidopteran species which synthesize different FACs in different compositions. Based on these works together with the recent publications about FACs in a plant–herbivore interaction, we discuss the variation in FAC patterns in...
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efficient incorporation of free oxygen into Volicitin in spodoptera litura common cutworm larvae
Bioscience Biotechnology and Biochemistry, 2009Co-Authors: Chihiro Ishikawa, Naoko Yoshinaga, Takako Aboshi, Ritsuo Nishida, Naoki MoriAbstract:Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] has previously been identified from the lepidopteran larval regurgitant as an elicitor of plant volatile emission. The efficient incorporation of free oxygen into Volicitin by Spodoptera litura larvae is demonstrated here by rearing them under 18O2 for three days. 18O-labeling of the hydroxyl group of Volicitin was confirmed by liquid chromatography/mass spectrometry-ion trap-time-of-flight (LC/MS-IT-TOF) and suggests the activity of a monooxygenase in Volicitin biosynthesis.
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active role of fatty acid amino acid conjugates in nitrogen metabolism in spodoptera litura larvae
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Naoko Yoshinaga, Hans T Alborn, Takako Aboshi, Ritsuo Nishida, J H Tumlinson, Naoki MoriAbstract:Since the first fatty acid amino acid conjugate (FAC) was isolated from regurgitant of Spodoptera exigua larvae in 1997 [Volicitin: N-(17-hydroxylinolenoyl)-l-glutamine], their role as elicitors of induced responses in plants has been well documented. However, studies of the biosyntheses and the physiological role of FACs in the insect have been minimal. By using 14C-labeled glutamine, glutamic acid, and linolenic acid in feeding studies of Spodoptera litura larvae, combined with tissue analyses, we found glutamine in the midgut cells to be a major source for biosynthesis of FACs. Furthermore, 20% of the glutamine moiety of FACs was derived from glutamic acid and ammonia through enzymatic reaction of glutamine synthetase (GS). To determine whether FACs improve GS productivity, we studied nitrogen assimilation efficiency of S. litura larvae fed on artificial diets containing 15NH4Cl and glutamic acid. When the diet was enriched with linolenic acid, the nitrogen assimilation efficiency improved from 40% to >60%. In the lumen, the biosynthesized FACs are hydrolyzed to fatty acids and glutamine, which are reabsorbed into tissues and hemolymph. These results strongly suggested that FACs play an active role in nitrogen assimilation in Lepidoptera larva and that glutamine containing FACs in the gut lumen may function as a form of storage of glutamine, a key compound of nitrogen metabolism.
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fatty acid amides previously identified in caterpillars found in the cricket teleogryllus taiwanemma and fruit fly drosophila melanogaster larvae
Journal of Chemical Ecology, 2007Co-Authors: Naoko Yoshinaga, Takako Aboshi, Chihiro Ishikawa, Masao Fukui, Masami Shimoda, Ritsuo Nishida, James H. Tumlinson, Cameron G. Lait, Naoki MoriAbstract:Fatty acid amides (FAAs) are known elicitors that induce plants to release volatile compounds that, in turn, attract foraging parasitoids. Since the discovery of Volicitin [N-(17-hydroxylinolenoyl)-l-glutamine] in the regurgitant of larval Spodoptera exigua, a series of related FAAs have been identified in several other species of lepidopteran caterpillars. We screened 13 non-lepidopteran insects for the presence of FAAs and found that these compounds were present in adults of two closely related cricket species, Teleogryllus taiwanemma and T. emma (Orthoptera: Gryllidae), and larvae of the fruit fly, Drosophila melanogaster (Diptera: Drosophilidae). When analyzed by liquid chromatography/mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF), the gut contents of both crickets had nearly identical FAA composition, the major FAAs comprising N-linolenoyl-l-glutamic acid and N-linoleoyl-l-glutamic acid. There were also two previously uncharacterized FAAs that were thought to be hydroxylated derivatives of these glutamic acid conjugates, based on their observed fragmentation patterns. In addition to these four FAAs containing glutamic acid, N-linolenoyl-l-glutamine and a small amount of Volicitin were detected. In D. melanogaster, N-linolenoyl-l-glutamic acid and N-linoleoyl-l-glutamic acid were the major FAAs found in larval extracts, while hydroxylated glutamic acid conjugates, Volicitin and N-linolenoyl-l-glutamine, were detected as trace components. Although these FAAs were not found in ten of the insects studied here, their identification in two additional orders of insects suggests that FAAs are more common than previously reported and may have physiological roles in a wide range of insects besides caterpillars.
Hans T Alborn - One of the best experts on this subject based on the ideXlab platform.
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phytohormone based activity mapping of insect herbivore produced elicitors
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Eric A Schmelz, Hans T Alborn, James H. Tumlinson, Jurgen Engelberth, Peter E A TealAbstract:In response to insect attack, many plants exhibit dynamic biochemical changes, resulting in the induced production of direct and indirect defenses. Elicitors present in herbivore oral secretions are believed to positively regulate many inducible plant defenses; however, little is known about the specificity of elicitor recognition in plants. To investigate the phylogenic distribution of elicitor activity, we tested representatives from three different elicitor classes on the time course of defense-related phytohormone production, including ethylene (E), jasmonic acid (JA), and salicylic acid, in a range of plant species spanning angiosperm diversity. All families examined responded to at least one elicitor class with significant increases in E and JA production within 1 to 2 h after treatment, yet elicitation activity among species was highly idiosyncratic. The fatty-acid amino acid conjugate Volicitin exhibited the widest range of phytohormone and volatile inducing activity, which spanned maize (Zea mays), soybean (Glycine max), and eggplant (Solanum melongena). In contrast, the activity of inceptin-related peptides, originally described in cowpea (Vigna unguiculata), was limited even within the Fabaceae. Similarly, caeliferin A16:0, a disulfooxy fatty acid from grasshoppers, was the only elicitor with demonstrable activity in Arabidopsis thaliana. Although precise mechanisms remain unknown, the unpredictable nature of elicitor activity between plant species supports the existence of specific receptor-ligand interactions mediating recognition. Despite the lack of an ideal plant model for studying the action of numerous elicitors, E and JA exist as highly conserved and readily quantifiable markers for future discoveries in this field.
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active role of fatty acid amino acid conjugates in nitrogen metabolism in spodoptera litura larvae
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Naoko Yoshinaga, Hans T Alborn, Takako Aboshi, Ritsuo Nishida, J H Tumlinson, Naoki MoriAbstract:Since the first fatty acid amino acid conjugate (FAC) was isolated from regurgitant of Spodoptera exigua larvae in 1997 [Volicitin: N-(17-hydroxylinolenoyl)-l-glutamine], their role as elicitors of induced responses in plants has been well documented. However, studies of the biosyntheses and the physiological role of FACs in the insect have been minimal. By using 14C-labeled glutamine, glutamic acid, and linolenic acid in feeding studies of Spodoptera litura larvae, combined with tissue analyses, we found glutamine in the midgut cells to be a major source for biosynthesis of FACs. Furthermore, 20% of the glutamine moiety of FACs was derived from glutamic acid and ammonia through enzymatic reaction of glutamine synthetase (GS). To determine whether FACs improve GS productivity, we studied nitrogen assimilation efficiency of S. litura larvae fed on artificial diets containing 15NH4Cl and glutamic acid. When the diet was enriched with linolenic acid, the nitrogen assimilation efficiency improved from 40% to >60%. In the lumen, the biosynthesized FACs are hydrolyzed to fatty acids and glutamine, which are reabsorbed into tissues and hemolymph. These results strongly suggested that FACs play an active role in nitrogen assimilation in Lepidoptera larva and that glutamine containing FACs in the gut lumen may function as a form of storage of glutamine, a key compound of nitrogen metabolism.
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nitrogen deficiency increases Volicitin induced volatile emission jasmonic acid accumulation and ethylene sensitivity in maize
Plant Physiology, 2003Co-Authors: Eric A Schmelz, Hans T Alborn, Jurgen Engelberth, J H TumlinsonAbstract:Insect herbivore-induced plant volatile emission and the subsequent attraction of natural enemies is facilitated by fatty acid-amino acid conjugate (FAC) elicitors, such as Volicitin [N-(17-hydroxylinolenoyl)-l-glutamine], present in caterpillar oral secretions. Insect-induced jasmonic acid (JA) and ethylene (E) are believed to mediate the magnitude of this variable response. In maize (Zea mays) seedlings, we examined the interaction of Volicitin, JA, and E on the induction of volatile emission at different levels of nitrogen (N) availability that are known to influence E sensitivity. N availability and Volicitin-induced sesquiterpene emission are inversely related as maximal responses were elicited in N-deficient plants. Plants with low N availability demonstrated similar volatile responses to Volicitin (1 nmol plant-1) and JA (100 nmol plant-1). In contrast, plants with medium N availability released much lower amounts of Volicitin-induced sesquiterpenes compared with JA, suggesting an alteration in Volicitin-induced JA levels. As predicted, low N plants exhibited greater sustained increases in wound- and Volicitin-induced JA levels compared with medium N plants. N availability also altered Volicitin-E interactions. In low N plants, E synergized Volicitin-induced sesquiterpene and indole emission 4- to 12-fold, with significant interactions first detected at 10 nL L-1 E. Medium N plants demonstrated greatly reduced Volicitin-E interactions. Volicitin-induced sesquiterpene emission was increased by E and was decreased by pretreatment the E perception inhibitor 1-methylcyclopropene without alteration in Volicitin-induced JA levels. N availability influences plant responses to insect-derived elicitors through changes in E sensitivity and E-independent JA kinetics.
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synergistic interactions between Volicitin jasmonic acid and ethylene mediate insect induced volatile emission in zea mays
Physiologia Plantarum, 2003Co-Authors: Eric A Schmelz, Hans T Alborn, James H. TumlinsonAbstract:Plants display differential responses following mechanical damage and insect herbivory. Both caterpillar attack and the application of caterpillar oral secretions (OS) to wounded leaves stimulates volatile emission above mechanical damage alone. Volicitin (N-17-hydroxylinolenoyl-l-glutamine), present in beet armyworm (BAW, Spodoptera exigua) OS, is a powerful elicitor of volatiles in excised maize seedlings (Zea mays cv. Delprim). We consider some of the mechanistic differences between wounding and insect herbivory in maize by examining the activity of Volicitin, changes in jasmonic acid (JA) levels, and volatile emission from both intact plant and excised leaf bioassays. Compared to mechanical damage alone, Volicitin stimulated increases in both JA levels and sesquiterpene volatiles when applied to intact plants. In a bioassay comparison, excised leaves were more sensitive and produced far greater volatile responses than intact plants following applications of both Volicitin and JA. In the excised leaf bioassay, Volicitin applications (10-500 pmol) to wounded leaves resulted in dose dependent JA increases and a direct positive relationship between JA and sesquiterpene volatile emission. Interestingly, Volicitin-induced JA levels did not differ between intact and excised bioassays, suggesting a possible interaction of JA with other regulatory signals in excised plants. In addition to JA, insect herbivory is known to stimulate the production of ethylene. Significant increases in ethylene were induced only by BAW herbivory and not by either wounding or Volicitin treatments. Using intact plant bioassays, ethylene (at 1 micro l l-1 or less) greatly promoted volatile emission induced by Volicitin and JA but not mechanical damage alone. For intact plants, wounding, elicitor-induced JA and insect-induced ethylene appear to be important interacting components in the stimulation of insect-induced volatile emission.
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induction of volatile emissions in maize by different larval instars of spodoptera littoralis
Journal of Chemical Ecology, 2003Co-Authors: Sandrine Gouinguene, Hans T Alborn, Ted C J TurlingsAbstract:Maize plants under attack by caterpillars emit a specific blend of volatiles that is highly attractive to parasitic wasps. The release of these signals is induced by elicitors in the caterpillar regurgitant. Studies suggest that plants respond differently to different herbivore species and even to different herbivore stages, thus providing parasitoids and predators with specific signals. We tested if this is the case for different larval instars of the noctuid moth Spodoptera littoralis when they feed on maize plants. Cut maize plants were incubated in diluted regurgitant from second, third, or fifth instar caterpillars. There were no differences in total amount released after these treatments, but there were small differences in the release of the minor compounds phenethyl acetate and α-humulene. Regurgitant of all three instars contained the elicitor Volicitin. To test the effect of actual feeding by the larvae, potted plants were infested with caterpillars of one of the three instars, and volatiles were collected the following day. The intensity of the emissions was correlated with the number of larvae feeding on a plant, and with the amount of damage inflicted, but was independent of the instar that caused the damage. We also used artificial damage to mimic the manner of feeding of each instar to test the importance of physical aspects of damages for the odor emission. The emission was highly variable, but no differences were found among the different types of damage. In olfactometer tests, Microplitis rufiventris, a parasitoid that can only successfully parasitize second and early third instar S. littoralis, did not differentiate among the odors of maize plants attacked by different instar larvae. The odor analyses as well as the parasitoid's responses indicate that maize odors induced by S. littoralis provide parasitoids with poor information on the larval developmental stage. We discuss the results in the context of variability and lack of specificity in odorous plant signals.
Paul W Pare - One of the best experts on this subject based on the ideXlab platform.
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Elicitors and priming agents initiate plant defense responses.
Photosynthesis Research, 2005Co-Authors: Paul W Pare, Mohamed A. Farag, Venkat Krishnamachari, Huiming Zhang, Choong-min Ryu, Joseph W. KloepperAbstract:Biotic elicitors produced by plant pathogens or herbivore pests rapidly activate a range of plant chemical defenses when translocated to plant tissue. The fatty acid conjugate Volicitin has proven to be a robust elicitor model for studying herbivore-induced plant defense responses. Here we review the role of insect-derived Volicitin (N-[17-hydroxylinolenoyl]-L-glutamine) as an authentic elicitor of defense responses, specifically as an activator of signal volatiles that attract natural enemies of herbivore pests. Comparisons are drawn between Volicitin as an elicitor of plant defenses and two other classes of signaling molecules, C6 green-leaf volatiles and C4 bacterial volatiles that appear to prime plant defenses thereby enhancing the capacity to mobilize cellular defense responses when a plant is faced with herbivore or pathogen attack.
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in situ translocation of Volicitin by beet armyworm larvae to maize and systemic immobility of the herbivore elicitor in planta
Planta, 2004Co-Authors: Christopher L Truitt, Paul W PareAbstract:Volicitin (N-[17-hydroxylinolenoyl]-l glutamine) present in the regurgitant of beet armyworm (Spodoptera exigua) activates the emissions of volatile organic compounds (VOCs) when in contact with damaged corn (Zea mays L.) leaves. VOC emission in turn serves as a signaling defense for the plant by attracting female parasitic wasps that prey on herbivore larvae. Chemical tracking of Volicitin within plants has yet to be reported. Here we present biochemical data that beet armyworm regurgitant serves as a vector for the introduction of Volicitin to the site of leaf damage under natural feeding conditions. Corn seedlings were 14CO2-labeled in situ, and beet armyworm larvae were allowed to feed on the labeled leaves. Herbivore oral secretions collected from late-third-instar larvae contained approximately 120 pmol Volicitin (0.05 nCi pmol−1) per larva. When radiochemically labeled larvae were placed on unlabeled leaves, the amount of Volicitin introduced to the damaged site was approximately 5.0 nCi (calc. 100 pmol/larvae). The mobility of Volicitin in leaves was examined by allowing radiolabeled beet armyworms to feed on unlabeled plants. In such tracking experiments, radioactivity was not detected in the upper leaves; however, the exogenous application of 5 nCi of [U-14C]sucrose to the lower leaf did result in subsequent radioactivity being detected in the upper portion of the plant. The detection of labeled sucrose with the same radioactivity as that of administered Volicitin indicated that Volicitin was not readily transported to undamaged leaves and that Volicitin may not directly serve as a mobile messenger in triggering the emissions of VOCs systemically.
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a plasma membrane protein from zea mays binds with the herbivore elicitor Volicitin
The Plant Cell, 2004Co-Authors: Christopher L Truitt, Hanxun Wei, Paul W PareAbstract:Volicitin (17-hydroxylinolenoyl-L-Gln) present in the regurgitant of Spodoptera exigua (beet armyworm caterpillars) activates the emission of volatile organic compounds (VOCs) when in contact with damaged Zea mays cv Delprim (maize) leaves. VOC emissions in turn serve as a signaling defense for the plant by attracting female parasitic wasps that prey on herbivore larvae. A tritiated form of Volicitin was synthesized and shown to induce volatiles in the same fashion as the biological form. [3H]-L-Volicitin rapidly, reversibly, and saturably bound to enriched plasma membrane fractions isolated from Z. mays leaves with an apparent Kd of 1.3 nM and a Hill coefficient of 1.07. Analog studies showed that the L-Gln and hydroxy moieties of Volicitin play an important role in binding. Treatment of plants with methyl jasmonate (MeJA) increased the total binding of [ 3 H]-L-Volicitin to the enriched plasma membrane more than threefold, suggesting that MeJA activates transcription of the gene encoding the binding protein. S. exigua feeding also increased total binding fourfold. Cycloheximide pretreatment of plants significantly decreased binding of radiolabeled Volicitin to the enriched plasma membrane. These data provide the first experimental evidence that initiation of plant defenses in response to herbivore damage can be mediated by a binding protein–ligand interaction.
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synthesis of hydroxy substituted unsaturated fatty acids and the amino acid insect derivative Volicitin
Tetrahedron Letters, 2003Co-Authors: Hanxun Wei, Christopher L Truitt, Paul W PareAbstract:Abstract An efficient synthesis of N -(17 S -hydroxylinolenoyl)- l -glutamine (Volicitin), a chemical elicitor from the herbivore-pest beet armyworm is presented. The synthesis, which utilizes a copper-catalyzed acetylene coupling, links ( S )-3,6-heptadiyne-2-ol with a C-8 propargylic iodine methyl ester to form the ( S )-17-hydroxylinolenate skeleton. By substituting different heptadiyne-2-ol groups, a series of methylene interrupted polyacetylene analogues were generated.
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lygus hesperus feeding and salivary gland extracts induce volatile emissions in plants
Journal of Chemical Ecology, 2002Co-Authors: Cesar Rodriguezsaona, Livy Williams, Steven J Craftsbrandner, Paul W PareAbstract:Induction of plant volatiles by leaf-chewing caterpillars is well documented. However, there is much less information about volatile induction by insects with different feeding habits. We studied the induction of plant volatiles by a piercing–sucking insect, the western tarnished plant bug Lygus hesperus Knight. Adults of both genders and nymphs of Lygus induced the local emission of a blend of volatiles from both cotton and maize. Feeding by Lygus also induced the systemic emission of volatiles that was similar but less complex than the blend emitted at the site of feeding. Infestation by mated, mature adult females (>4 days old), but not by nymphs or mature males, caused detectable emission of α-pinene, myrcene, and (E)-β-caryophyllene, compounds that are stored in the glands of cotton tissue. This indicated that damage to glands in the petiole and leaf by the female ovipositor, rather than feeding, contributed significantly to the emission of these volatiles. Girdling the plant stem to disrupt phloem transport markedly decreased the movement of 14C-labeled photosynthetic products to the apex of the plant, and this treatment also markedly reduced the amount of systemically induced volatiles caused by Lygus feeding. Lygus salivary gland extracts were capable of inducing emission of the same volatile blend as measured for plants infested by feeding insects or treated with Volicitin, an elicitor isolated from caterpillar regurgitant. The results indicate that L. hesperus is capable of inducing the emission of plant volatiles and that induction is caused by an elicitor that is contained in the insect salivary gland.
Naoko Yoshinaga - One of the best experts on this subject based on the ideXlab platform.
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N-(18-hydroxylinolenoyl)-L-glutamine: a newly discovered analog of Volicitin in Manduca sexta and its elicitor activity in plants.
Journal of chemical ecology, 2014Co-Authors: Naoko Yoshinaga, Takako Aboshi, Chihiro Ishikawa, James H. Tumlinson, Irmgard H. Seidl-adams, Elizabeth James Bosak, Naoki MoriAbstract:Plants attacked by insect herbivores release a blend of volatile organic compounds (VOCs) that serve as chemical cues for host location by parasitic wasps, natural enemies of the herbivores. Volicitin, N-(17-hydroxylinolenoyl)-l-glutamine, is one of the most active VOC elicitors found in herbivore regurgitants. Our previous study revealed that hydroxylation on the 17th position of the linolenic acid moiety of N-linolenoyl-l-glutamine increases by more than three times the elicitor activity in corn plants. Here, we identified N-(18-hydroxylinolenoyl)-l-glutamine (18OH-Volicitin) from larval gut contents of tobacco hornworm (THW), Manduca sexta. Eggplant and tobacco, two solanaceous host plants of THW larvae, and corn, a non-host plant, responded differently to this new elicitor. Eggplant and tobacco seedlings emitted twice the amount of VOCs when 18OH-Volicitin was applied to damaged leaf surfaces compared to N-linolenoyl-l-glutamine, while both these fatty acid amino acid conjugates (FACs) elicited a similar response in corn seedlings. In both solanaceous plants, there was no significant difference in the elicitor activity of 17OH- and 18OH-Volicitin. Interestingly, other lepidopteran species that have 17OH-type Volicitin also attack solanaceous plants. These data suggest that plants have developed herbivory-detection systems customized to their herbivorous enemies.
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function and evolutionary diversity of fatty acid amino acid conjugates in insects
Journal of Plant Interactions, 2011Co-Authors: Naoki Mori, Naoko YoshinagaAbstract:Abstract Some plants recognize herbivore attack and distinguish it from mechanical wounding because of the chemical components in caterpillar regurgitants. Volicitin and its related compounds, collectively called fatty acid amino acids conjugates (FACs), are such elicitors that function as key compounds to trigger volatile emissions in several plants and ironically help foraging parasitoids. But we do not know if the chemical structural differences of FACs in caterpillars can explain the complicated plant responses which sometimes vary depending on the caterpillar species. It is even unclear why caterpillars make a variety of FACs. Previously, we proposed a hypothesis that FACs might be an intermediate that enhance nitrogen assimilation in insects. Also we reported a broad range of lepidopteran species which synthesize different FACs in different compositions. Based on these works together with the recent publications about FACs in a plant–herbivore interaction, we discuss the variation in FAC patterns in...
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efficient incorporation of free oxygen into Volicitin in spodoptera litura common cutworm larvae
Bioscience Biotechnology and Biochemistry, 2009Co-Authors: Chihiro Ishikawa, Naoko Yoshinaga, Takako Aboshi, Ritsuo Nishida, Naoki MoriAbstract:Volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] has previously been identified from the lepidopteran larval regurgitant as an elicitor of plant volatile emission. The efficient incorporation of free oxygen into Volicitin by Spodoptera litura larvae is demonstrated here by rearing them under 18O2 for three days. 18O-labeling of the hydroxyl group of Volicitin was confirmed by liquid chromatography/mass spectrometry-ion trap-time-of-flight (LC/MS-IT-TOF) and suggests the activity of a monooxygenase in Volicitin biosynthesis.
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active role of fatty acid amino acid conjugates in nitrogen metabolism in spodoptera litura larvae
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Naoko Yoshinaga, Hans T Alborn, Takako Aboshi, Ritsuo Nishida, J H Tumlinson, Naoki MoriAbstract:Since the first fatty acid amino acid conjugate (FAC) was isolated from regurgitant of Spodoptera exigua larvae in 1997 [Volicitin: N-(17-hydroxylinolenoyl)-l-glutamine], their role as elicitors of induced responses in plants has been well documented. However, studies of the biosyntheses and the physiological role of FACs in the insect have been minimal. By using 14C-labeled glutamine, glutamic acid, and linolenic acid in feeding studies of Spodoptera litura larvae, combined with tissue analyses, we found glutamine in the midgut cells to be a major source for biosynthesis of FACs. Furthermore, 20% of the glutamine moiety of FACs was derived from glutamic acid and ammonia through enzymatic reaction of glutamine synthetase (GS). To determine whether FACs improve GS productivity, we studied nitrogen assimilation efficiency of S. litura larvae fed on artificial diets containing 15NH4Cl and glutamic acid. When the diet was enriched with linolenic acid, the nitrogen assimilation efficiency improved from 40% to >60%. In the lumen, the biosynthesized FACs are hydrolyzed to fatty acids and glutamine, which are reabsorbed into tissues and hemolymph. These results strongly suggested that FACs play an active role in nitrogen assimilation in Lepidoptera larva and that glutamine containing FACs in the gut lumen may function as a form of storage of glutamine, a key compound of nitrogen metabolism.
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fatty acid amides previously identified in caterpillars found in the cricket teleogryllus taiwanemma and fruit fly drosophila melanogaster larvae
Journal of Chemical Ecology, 2007Co-Authors: Naoko Yoshinaga, Takako Aboshi, Chihiro Ishikawa, Masao Fukui, Masami Shimoda, Ritsuo Nishida, James H. Tumlinson, Cameron G. Lait, Naoki MoriAbstract:Fatty acid amides (FAAs) are known elicitors that induce plants to release volatile compounds that, in turn, attract foraging parasitoids. Since the discovery of Volicitin [N-(17-hydroxylinolenoyl)-l-glutamine] in the regurgitant of larval Spodoptera exigua, a series of related FAAs have been identified in several other species of lepidopteran caterpillars. We screened 13 non-lepidopteran insects for the presence of FAAs and found that these compounds were present in adults of two closely related cricket species, Teleogryllus taiwanemma and T. emma (Orthoptera: Gryllidae), and larvae of the fruit fly, Drosophila melanogaster (Diptera: Drosophilidae). When analyzed by liquid chromatography/mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF), the gut contents of both crickets had nearly identical FAA composition, the major FAAs comprising N-linolenoyl-l-glutamic acid and N-linoleoyl-l-glutamic acid. There were also two previously uncharacterized FAAs that were thought to be hydroxylated derivatives of these glutamic acid conjugates, based on their observed fragmentation patterns. In addition to these four FAAs containing glutamic acid, N-linolenoyl-l-glutamine and a small amount of Volicitin were detected. In D. melanogaster, N-linolenoyl-l-glutamic acid and N-linoleoyl-l-glutamic acid were the major FAAs found in larval extracts, while hydroxylated glutamic acid conjugates, Volicitin and N-linolenoyl-l-glutamine, were detected as trace components. Although these FAAs were not found in ten of the insects studied here, their identification in two additional orders of insects suggests that FAAs are more common than previously reported and may have physiological roles in a wide range of insects besides caterpillars.
James H. Tumlinson - One of the best experts on this subject based on the ideXlab platform.
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N-(18-hydroxylinolenoyl)-L-glutamine: a newly discovered analog of Volicitin in Manduca sexta and its elicitor activity in plants.
Journal of chemical ecology, 2014Co-Authors: Naoko Yoshinaga, Takako Aboshi, Chihiro Ishikawa, James H. Tumlinson, Irmgard H. Seidl-adams, Elizabeth James Bosak, Naoki MoriAbstract:Plants attacked by insect herbivores release a blend of volatile organic compounds (VOCs) that serve as chemical cues for host location by parasitic wasps, natural enemies of the herbivores. Volicitin, N-(17-hydroxylinolenoyl)-l-glutamine, is one of the most active VOC elicitors found in herbivore regurgitants. Our previous study revealed that hydroxylation on the 17th position of the linolenic acid moiety of N-linolenoyl-l-glutamine increases by more than three times the elicitor activity in corn plants. Here, we identified N-(18-hydroxylinolenoyl)-l-glutamine (18OH-Volicitin) from larval gut contents of tobacco hornworm (THW), Manduca sexta. Eggplant and tobacco, two solanaceous host plants of THW larvae, and corn, a non-host plant, responded differently to this new elicitor. Eggplant and tobacco seedlings emitted twice the amount of VOCs when 18OH-Volicitin was applied to damaged leaf surfaces compared to N-linolenoyl-l-glutamine, while both these fatty acid amino acid conjugates (FACs) elicited a similar response in corn seedlings. In both solanaceous plants, there was no significant difference in the elicitor activity of 17OH- and 18OH-Volicitin. Interestingly, other lepidopteran species that have 17OH-type Volicitin also attack solanaceous plants. These data suggest that plants have developed herbivory-detection systems customized to their herbivorous enemies.
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phytohormone based activity mapping of insect herbivore produced elicitors
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Eric A Schmelz, Hans T Alborn, James H. Tumlinson, Jurgen Engelberth, Peter E A TealAbstract:In response to insect attack, many plants exhibit dynamic biochemical changes, resulting in the induced production of direct and indirect defenses. Elicitors present in herbivore oral secretions are believed to positively regulate many inducible plant defenses; however, little is known about the specificity of elicitor recognition in plants. To investigate the phylogenic distribution of elicitor activity, we tested representatives from three different elicitor classes on the time course of defense-related phytohormone production, including ethylene (E), jasmonic acid (JA), and salicylic acid, in a range of plant species spanning angiosperm diversity. All families examined responded to at least one elicitor class with significant increases in E and JA production within 1 to 2 h after treatment, yet elicitation activity among species was highly idiosyncratic. The fatty-acid amino acid conjugate Volicitin exhibited the widest range of phytohormone and volatile inducing activity, which spanned maize (Zea mays), soybean (Glycine max), and eggplant (Solanum melongena). In contrast, the activity of inceptin-related peptides, originally described in cowpea (Vigna unguiculata), was limited even within the Fabaceae. Similarly, caeliferin A16:0, a disulfooxy fatty acid from grasshoppers, was the only elicitor with demonstrable activity in Arabidopsis thaliana. Although precise mechanisms remain unknown, the unpredictable nature of elicitor activity between plant species supports the existence of specific receptor-ligand interactions mediating recognition. Despite the lack of an ideal plant model for studying the action of numerous elicitors, E and JA exist as highly conserved and readily quantifiable markers for future discoveries in this field.
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fatty acid amides previously identified in caterpillars found in the cricket teleogryllus taiwanemma and fruit fly drosophila melanogaster larvae
Journal of Chemical Ecology, 2007Co-Authors: Naoko Yoshinaga, Takako Aboshi, Chihiro Ishikawa, Masao Fukui, Masami Shimoda, Ritsuo Nishida, James H. Tumlinson, Cameron G. Lait, Naoki MoriAbstract:Fatty acid amides (FAAs) are known elicitors that induce plants to release volatile compounds that, in turn, attract foraging parasitoids. Since the discovery of Volicitin [N-(17-hydroxylinolenoyl)-l-glutamine] in the regurgitant of larval Spodoptera exigua, a series of related FAAs have been identified in several other species of lepidopteran caterpillars. We screened 13 non-lepidopteran insects for the presence of FAAs and found that these compounds were present in adults of two closely related cricket species, Teleogryllus taiwanemma and T. emma (Orthoptera: Gryllidae), and larvae of the fruit fly, Drosophila melanogaster (Diptera: Drosophilidae). When analyzed by liquid chromatography/mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF), the gut contents of both crickets had nearly identical FAA composition, the major FAAs comprising N-linolenoyl-l-glutamic acid and N-linoleoyl-l-glutamic acid. There were also two previously uncharacterized FAAs that were thought to be hydroxylated derivatives of these glutamic acid conjugates, based on their observed fragmentation patterns. In addition to these four FAAs containing glutamic acid, N-linolenoyl-l-glutamine and a small amount of Volicitin were detected. In D. melanogaster, N-linolenoyl-l-glutamic acid and N-linoleoyl-l-glutamic acid were the major FAAs found in larval extracts, while hydroxylated glutamic acid conjugates, Volicitin and N-linolenoyl-l-glutamine, were detected as trace components. Although these FAAs were not found in ten of the insects studied here, their identification in two additional orders of insects suggests that FAAs are more common than previously reported and may have physiological roles in a wide range of insects besides caterpillars.
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synergistic interactions between Volicitin jasmonic acid and ethylene mediate insect induced volatile emission in zea mays
Physiologia Plantarum, 2003Co-Authors: Eric A Schmelz, Hans T Alborn, James H. TumlinsonAbstract:Plants display differential responses following mechanical damage and insect herbivory. Both caterpillar attack and the application of caterpillar oral secretions (OS) to wounded leaves stimulates volatile emission above mechanical damage alone. Volicitin (N-17-hydroxylinolenoyl-l-glutamine), present in beet armyworm (BAW, Spodoptera exigua) OS, is a powerful elicitor of volatiles in excised maize seedlings (Zea mays cv. Delprim). We consider some of the mechanistic differences between wounding and insect herbivory in maize by examining the activity of Volicitin, changes in jasmonic acid (JA) levels, and volatile emission from both intact plant and excised leaf bioassays. Compared to mechanical damage alone, Volicitin stimulated increases in both JA levels and sesquiterpene volatiles when applied to intact plants. In a bioassay comparison, excised leaves were more sensitive and produced far greater volatile responses than intact plants following applications of both Volicitin and JA. In the excised leaf bioassay, Volicitin applications (10-500 pmol) to wounded leaves resulted in dose dependent JA increases and a direct positive relationship between JA and sesquiterpene volatile emission. Interestingly, Volicitin-induced JA levels did not differ between intact and excised bioassays, suggesting a possible interaction of JA with other regulatory signals in excised plants. In addition to JA, insect herbivory is known to stimulate the production of ethylene. Significant increases in ethylene were induced only by BAW herbivory and not by either wounding or Volicitin treatments. Using intact plant bioassays, ethylene (at 1 micro l l-1 or less) greatly promoted volatile emission induced by Volicitin and JA but not mechanical damage alone. For intact plants, wounding, elicitor-induced JA and insect-induced ethylene appear to be important interacting components in the stimulation of insect-induced volatile emission.
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the influence of intact plant and excised leaf bioassay designs on Volicitin and jasmonic acid induced sesquiterpene volatile release in zea mays
Planta, 2001Co-Authors: Eric A Schmelz, Hans T Alborn, James H. TumlinsonAbstract:Induced plant responses to insect attack include the release of volatile chemicals. These volatiles are used as host-location signals by foraging parasitoids, which are natural enemies of insect herbivores. A plant's response to herbivory can be influenced by factors present in insect oral secretions. Volicitin (N-(17-hydroxylinolenoyl)-L-glutamine), identified in beet armyworm (Spodoptera exigua) oral secretions, stimulates volatile release in corn (Zea mays L.) seedlings in a manner similar to beet armyworm herbivory. Volicitin is hypothesized to trigger release of induced volatiles, at least in part, by modulating levels of the wound hormone, jasmonic acid (JA). We compare the sesquiterpene volatile release of damaged leaves treated with aqueous buffer only or with the same buffer containing Volicitin or JA. Leaves were damaged by scratching with a razor and test solutions were applied to the scratched area. The leaves were either excised from the plant or left intact shortly after this treatment. Plants were treated at three different times (designated as Evening, Midnight, and Morning) and volatiles were collected in the subsequent photoperiod. JA and Volicitin treatments stimulated the release of volatile sesquiterpenes, namely β-caryophyllene, (E)-α-bergamotene, and (E)-β-farnesene. In all cases, JA stimulated significant sesquiterpene release above mechanical damage alone. Volicitin induced an increase in sesquiterpene volatiles for all excised-leaf bioassays and the Midnight intact plants. Volicitin treatments in the Evening and Morning intact plants produced more sesquiterpenes than the untreated controls, while mechanical damage alone produced an intermediate response that did not differ from either treatment group. Excised leaves produced a 2.5- to 8.0-fold greater volatile response than similarly treated intact plants. Excision also altered the ratio of JA-and Volicitin-induced sesquiterpene release by preferentially increasing (E)-β-farnesene levels relative to β-caryophyllene. The inducibility of volatile release varied with time of treatment. On average, sesquiterpene release was highest in the Midnight excised leaves and lowest in the Morning intact plants. The duration of induced volatile release also differed between treatments. On average, JA produced a sustained release of sesquiterpenes over time, with over 20% of the combined sesquiterpenes released in the third and final volatile collection period. In contrast, less than 8% of the combined sesquiterpenes induced by Volicitin were emitted during this period. The large quantitative differences between intact plants and detached leaves suggest that the results of assays using excised tissues should be cautiously interpreted when considering intact-plant models.
