31 results on '"Niinemets, Ülo"'
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2. The Capacity for Thermal Protection of Photosynthetic Electron Transport Varies for Different Monoterpenes in Quercus ilex
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Filella, Iolanda, Llusià, Joan, Niinemets, Ülo, and Peñuelas, Josep
- Published
- 2005
3. Stomatal Constraints May Affect Emission of Oxygenated Monoterpenoids from the Foliage of Pinus pinea
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Niinemets, Ülo, Reichstein, Markus, Staudt, Michael, Seufert, Günther, and Tenhunen, John D.
- Published
- 2002
4. Monoterpene Emissions in Relation to Foliar Photosynthetic and Structural Variables in Mediterranean Evergreen Quercus Species
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Niinemets, Ülo, Hauff, Karin, Bertin, Nadia, Tenhunen, John D., Steinbrecher, Rainer, and Seufert, Günther
- Published
- 2002
5. A Model Coupling Foliar Monoterpene Emissions to Leaf Photosynthetic Characteristics in Mediterranean Evergreen Quercus Species
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Niinemets, Ülo, Seufert, Günther, Steinbrecher, Rainer, and Tenhunen, John D.
- Published
- 2002
6. Measurement of volatile terpene emissions in 70 dominant vascular plant species in Hawaii: aliens emit more than natives
- Author
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Llusià, Joan, Peñuelas, Josep, Sardans, Jordi, Owen, Susan M., and Niinemets, Ülo
- Published
- 2010
- Full Text
- View/download PDF
7. Leaf rust induced volatile organic compounds signalling in willow during the infection
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Toome, Merje, Randjärv, Pille, Copolovici, Lucian, Niinemets, Ülo, Heinsoo, Katrin, Luik, Anne, and Noe, Steffen M.
- Published
- 2010
8. Foliar Mono- and Sesquiterpene Contents in Relation to Leaf Economic Spectrum in Native and Alien Species in Oahu (Hawai’i)
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Sardans, Jordi, Llusià, Joan, Niinemets, Ülo, Owen, Sue, and Peñuelas, Josep
- Published
- 2010
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9. Lethal heat stress-dependent volatile emissions from tobacco leaves: what happens beyond the thermal edge?
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Turan, Satpal, Kask, Kaia, Kanagendran, Arooran, Li, Shuai, Anni, Rinaldo, Talts, Eero, Rasulov, Bahtijor, Kännaste, Astrid, and Niinemets, Ülo
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SHOCK therapy ,HEAT ,QUANTUM efficiency ,LEAVES ,HIGH temperatures ,TOBACCO - Abstract
Natural vegetation is predicted to suffer from extreme heat events as a result of global warming. In this study, we focused on the immediate response to heat stress. Photosynthesis and volatile emissions were measured in the leaves of tobacco (Nicotiana tabacum cv. Wisconsin 38) after exposure to heat shock treatments between 46 °C and 55 °C. Exposure to 46 °C decreased photosynthetic carbon assimilation rates (A) by >3-fold. Complete inhibition of A was observed at 49 °C, together with a simultaneous decrease in the maximum quantum efficiency of PSII, measured as the F
v / Fm ratio. A large increase in volatile emissions was observed at 52 °C. Heat stress resulted in only minor effects on the emission of monoterpenes, but volatiles associated with membrane damage such as propanal and (E)-2-hexenal+(Z)-3-hexenol were greatly increased. Heat induced changes in the levels of methanol and 2-ethylfuran that are indicative of modification of cell walls. In addition, the oxidation of metabolites in the volatile profiles was strongly enhanced, suggesting the acceleration of oxidative processes at high temperatures that are beyond the thermal tolerance limit. [ABSTRACT FROM AUTHOR]- Published
- 2019
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10. Nutrient‐rich plants emit a less intense blend of volatile isoprenoids.
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Fernández‐Martínez, Marcos, Llusià, Joan, Filella, Iolanda, Niinemets, Ülo, Arneth, Almut, Wright, Ian J., Loreto, Francesco, and Peñuelas, Josep
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ISOPENTENOIDS ,BIOMES ,PLANT phylogeny ,MONOTERPENES ,ISOPRENE - Abstract
Summary: The emission of isoprenoids (e.g. isoprene and monoterpenes) by plants plays an important defensive role against biotic and abiotic stresses. Little is known, however, about the functional traits linked to species‐specific variability in the types and rates of isoprenoids emitted and about possible co‐evolution of functional traits with isoprenoid emission type (isoprene emitter, monoterpene emitter or both).We combined data for isoprene and monoterpene emission rates per unit dry mass with key functional traits (foliar nitrogen (N) and phosphorus (P) concentrations, and leaf mass per area) and climate for 113 plant species, covering the boreal, wet temperate, Mediterranean and tropical biomes.Foliar N was positively correlated with isoprene emission, and foliar P was negatively correlated with both isoprene and monoterpene emission rate. Nonemitting plants generally had the highest nutrient concentrations, and those storing monoterpenes had the lowest concentrations. Our phylogenetic analyses found that the type of isoprenoid emission followed an adaptive, rather than a random model of evolution.Evolution of isoprenoids may be linked to nutrient availability. Foliar N and P are good predictors of the type of isoprenoid emission and the rate at which monoterpenes, and to a lesser extent isoprene, are emitted. See also the Editorial by Kessler, 220: 655–658. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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11. Methyl jasmonate-induced emission of biogenic volatiles is biphasic in cucumber: a high-resolution analysis of dose dependence.
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Yifan Jiang, Jiayan Ye, Shuai Li, and Niinemets, Ülo
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JASMONATE ,PROTON transfer reactions ,METHANOL ,LIPOXYGENASES ,MONOTERPENES - Abstract
Methyl jasmonate (MeJA) is a key airborne elicitor activating jasmonate-dependent signaling pathways, including induction of stress-related volatile emissions, but how the magnitude and timing of these emissions scale with MeJA dose is not known. Treatments with exogenous MeJA concentrations ranging from mild (0.2 mM) to lethal (50 mM) were used to investigate quantitative relationships among MeJA dose and the kinetics and magnitude of volatile release in Cucumis sativus by combining high-resolution measurements with a proton-transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) and GC-MS. The results highlighted biphasic kinetics of elicitation of volatiles. The early phase, peaking in 0.1-1 h after the MeJA treatment, was characterized by emissions of lipoxygenase (LOX) pathway volatiles and methanol. In the subsequent phase, starting in 6-12 h and reaching a maximum in 15-25 h after the treatment, secondary emissions of LOX compounds as well as emissions of monoterpenes and sesquiterpenes were elicited. For both phases, the maximum emission rates and total integrated emissions increased with applied MeJA concentration. Furthermore, the rates of induction and decay, and the duration of emission bursts were positively, and the timing of emission maxima were negatively associated with MeJA dose for LOX compounds and terpenoids, except for the duration of the first LOX burst. These results demonstrate major effects of MeJA dose on the kinetics and magnitude of volatile response, underscoring the importance of biotic stress severity in deciphering the downstream events of biological impacts. [ABSTRACT FROM AUTHOR]
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- 2017
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12. The Capacity for Thermal Protection of Photosynthetic Electron Transport Varies for Different Monoterpenes in Quercus ilex1
- Author
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Copolovici, Lucian O., Filella, Iolanda, Llusià, Joan, Niinemets, Ülo, and Peñuelas, Josep
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Electron Transport ,Plant Leaves ,Quercus ,Hot Temperature ,Cyclohexenes ,Monoterpenes ,Biological Transport ,Cyclohexane Monoterpenes ,Photosynthesis ,Research Article ,Bicyclic Monoterpenes - Abstract
Heat stress resistance of foliar photosynthetic apparatus was investigated in the Mediterranean monoterpene-emitting evergreen sclerophyll species Quercus ilex. Leaf feeding with fosmidomycin, which is a specific inhibitor of the chloroplastic isoprenoid synthesis pathway, essentially stopped monoterpene emission and resulted in the decrease of the optimum temperature of photosynthetic electron transport from approximately 38 degrees C to approximately 30 degrees C. The heat stress resistance was partly restored by fumigation with 4 to 5 nmol mol(-1) air concentrations of monoterpene alpha-pinene but not with fumigations with monoterpene alcohol alpha-terpineol. Analyses of monoterpene physicochemical characteristics demonstrated that alpha-pinene was primarily distributed to leaf gas and lipid phases, while alpha-terpineol was primarily distributed to leaf aqueous phase. Thus, for a common monoterpene uptake rate, alpha-terpineol is less efficient in stabilizing membrane liquid-crystalline structure and as an antioxidant in plant membranes. Furthermore, alpha-terpineol uptake rate (U) strongly decreased with increasing temperature, while the uptake rates of alpha-pinene increased with increasing temperature, providing a further explanation of the lower efficiency of thermal protection by alpha-terpineol. The temperature-dependent decrease of alpha-terpineol uptake was both due to decreases in stomatal conductance, g(w), and increased volatility of alpha-terpineol at higher temperature that decreased the monoterpene diffusion gradient between the ambient air (F(A)) and leaf (F(I); U = g(w)[F(A) - F(I)]). Model analyses suggested that alpha-pinene reacted within the leaf at higher temperatures, possibly within the lipid phase, thereby avoiding the decrease in diffusion gradient, F(A) - F(I). Thus, these data contribute to the hypothesis of the antioxidative protection of leaf membranes during heat stress by monoterpenes. These data further suggest that fumigation with the relatively low atmospheric concentrations of monoterpenes that are occasionally observed during warm windless days in the Mediterranean canopies may significantly improve the heat tolerance of nonemitting vegetation that grows intermixed with emitting species.
- Published
- 2005
13. How specialized volatiles respond to chronic and short-term physiological and shock heat stress in Brassica nigra.
- Author
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Kask, Kaia, Kännaste, Astrid, Talts, Eero, Copolovici, Lucian, and Niinemets, Ülo
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PHYSIOLOGICAL effects of heat ,MUSTARD ,GLUCOSINOLATES ,MONOTERPENES ,LIPOXYGENASES - Abstract
Brassicales release volatile glucosinolate breakdown products upon tissue mechanical damage, but it is unclear how the release of glucosinolate volatiles responds to abiotic stresses such as heat stress. We used three different heat treatments, simulating different dynamic temperature conditions in the field to gain insight into stress-dependent changes in volatile blends and photosynthetic characteristics in the annual herb Brassica nigra (L.) Koch. Heat stress was applied by either heating leaves through temperature response curve measurements from 20 to 40 °C (mild stress), exposing plants for 4 h to temperatures 25-44 °C (long-term stress) or shock-heating leaves to 45-50 °C. Photosynthetic reduction through temperature response curves was associated with decreased stomatal conductance, while the reduction due to long-term stress and collapse of photosynthetic activity after heat shock stress were associated with non-stomatal processes. Mild stress decreased constitutive monoterpene emissions, while long-term stress and shock stress resulted in emissions of the lipoxygenase pathway and glucosinolate volatiles. Glucosinolate volatile release was more strongly elicited by long-term stress and lipoxygenase product released by heat shock. These results demonstrate that glucosinolate volatiles constitute a major part of emission blend in heat-stressed B. nigra plants, especially upon chronic stress that leads to induction responses. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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14. Scaling of photosynthesis and constitutive and induced volatile emissions with severity of leaf infection by rust fungus (Melampsora larici-populina) in Populus balsamifera var. suaveolens.
- Author
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Yifan Jiang, Jiayan Ye, Veromann, Linda-Liisa, and Niinemets, Ülo
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BALSAM poplar ,MELAMPSORA diseases ,PHOTOSYNTHESIS ,VOLATILE organic compounds ,MONOTERPENES ,ISOPRENE ,FUNGAL diseases of plants ,PLANT metabolism - Abstract
Fungal infections result in decreases in photosynthesis, induction of stress and signaling volatile emissions and reductions in constitutive volatile emissions, but the way different physiological processes scale with the severity of infection is poorly known. We studied the effects of infection by the obligate biotrophic fungal pathogen Melampsora larici-populina Kleb., the causal agent of poplar leaf rust disease, on photosynthetic characteristics, and constitutive isoprene and induced volatile emissions in leaves of Populus balsamifera var. suaveolens (Fisch.) Loudon. exhibiting different degrees of damage. The degree of fungal damage, quantified by the total area of chlorotic and necrotic leaf areas, varied between 0 (noninfected control) and ~60%. The rates of all physiological processes scaled quantitatively with the degree of visual damage, but the scaling with damage severity was weaker for photosynthetic characteristics than for constitutive and induced volatile release. Over the whole range of damage severity, the net assimilation rate per area (A
A ) decreased 1.5-fold, dry mass per unit area 2.4-fold and constitutive isoprene emissions 5-fold, while stomatal conductance increased 1.9-fold and dark respiration rate 1.6-fold. The emissions of key stress and signaling volatiles (methanol, green leaf volatiles, monoterpenes, sesquiterpenes and methyl salicylate) were in most cases nondetectable in noninfested leaves, and increased strongly with increasing the spread of infection. The moderate reduction in AA resulted from the loss of photosynthetically active biomass, but the reduction in constitutive isoprene emissions and the increase in induced volatile emissions primarily reflected changes in the activities of corresponding biochemical pathways. Although all physiological alterations in fungal-infected leaves occurred in a stress severity-dependent manner, modifications in primary and secondary metabolic pathways scaled differently due to contrasting operational mechanisms. [ABSTRACT FROM AUTHOR]- Published
- 2016
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15. Germacrene A synthase in yarrow (Achillea millefolium) is an enzyme with mixed substrate specificity: gene cloning, functional characterization and expression analysis.
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Pazouki, Leila, Memari, Hamid R., Kännaste, Astrid, Bichele, Rudolf, and Niinemets, Ülo
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YARROW ,TERPENES synthesis ,PLANT genetics ,GENETIC research ,GENE expression in plants ,BACTERIAL genetics ,ESCHERICHIA coli - Abstract
Terpenoid synthases constitute a highly diverse gene family producing a wide range of cyclic and acyclic molecules consisting of isoprene (C5) residues. Often a single terpene synthase produces a spectrum of molecules of given chain length, but some terpene synthases can use multiple substrates, producing products of different chain length. Only a few such enzymes has been characterized, but the capacity for multiple-substrate use can be more widespread than previously thought. Here we focused on germacrene A synthase (GAS) that is a key cytosolic enzyme in the sesquiterpene lactone biosynthesis pathway in the important medicinal plant Achillea millefolium (AmGAS). The full length encoding gene was heterologously expressed in Escherichia coli BL21 (DE3), functionally characterized, and its in vivo expression was analyzed. The recombinant protein catalyzed formation of germacrene A with the C15 substrate farnesyl diphosphate (FDP), while acyclic monoterpenes were formed with the C10 substrate geranyl diphosphate (GDP) and cyclic monoterpenes with the C10 substrate neryl diphosphate (NDP). Although monoterpene synthesis has been assumed to be confined exclusively to plastids, AmGAS can potentially synthesize monoterpenes in cytosol when GDP or NDP become available. AmGAS enzyme had high homology with GAS sequences from other Asteraceae species, suggesting that multi-substrate use can be more widespread among germacrene A synthases than previously thought. Expression studies indicated that AmGAS was expressed in both autotrophic and heterotrophic plant compartments with the highest expression levels in leaves and flowers. To our knowledge, this is the first report on the cloning and characterization of germacrene A synthase coding gene in A. millefolium, and multi-substrate use of GAS enzymes. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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16. Changes in floral bouquets from compound-specific responses to increasing temperatures.
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Farré‐Armengol, Gerard, Filella, Iolanda, Llusià, Joan, Niinemets, Ülo, and Peñuelas, Josep
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EFFECT of temperature on plants ,VEGETATION & climate ,GAS chromatography/Mass spectrometry (GC-MS) ,FLOWERS ,POLLINATORS - Abstract
We addressed the potential effects of changes in ambient temperature on the profiles of volatile emissions from flowers and tested whether warming could induce significant quantitative and qualitative changes in floral emissions, which would potentially interfere with plant-pollinator chemical communication. We measured the temperature responses of floral emissions of various common species of Mediterranean plants using dynamic headspace sampling and used GC- MS to identify and quantify the emitted terpenes. Floral emissions increased with temperature to an optimum and thereafter decreased. The responses to temperature modeled here predicted increases in the rates of floral terpene emission of 0.03-1.4-fold, depending on the species, in response to an increase of 1 °C in the mean global ambient temperature. Under the warmest projections that predict a maximum increase of 5 °C in the mean temperature of Mediterranean climates in the Northern Hemisphere by the end of the century, our models predicted increases in the rates of floral terpene emissions of 0.34-9.1-fold, depending on the species. The species with the lowest emission rates had the highest relative increases in floral terpene emissions with temperature increases of 1-5 °C. The response of floral emissions to temperature differed among species and among different compounds within the species. Warming not only increased the rates of total emissions, but also changed the ratios among compounds that constituted the floral scents, i.e. increased the signal for pollinators, but also importantly altered the signal fidelity and probability of identification by pollinators, especially for specialists with a strong reliance on species-specific floral blends. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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17. Highly variable chemical signatures over short spatial distances among Scots pine (Pinus sylvestris) populations.
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Kännaste, Astrid, Copolovici, Lucian, Pazouki, Leila, Suhhorutšenko, Marina, and Niinemets, Ülo
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SCOTS pine ,COMPOSITION of leaves ,MONOTERPENES ,SESQUITERPENES ,PLANT chemical analysis ,PHYSIOLOGY - Abstract
Understanding within-species variability in terpenoid content and composition is highly relevant for predicting species adaptive potential to biotic stresses, but there is still limited information on terpene variations even for widespread species. We studied the foliage content and composition of terpenoids, foliage structure, and carbon (C) and nitrogen (N) contents in Pinus sylvestris L. in four Estonian sites ranging from dry forest to raised bog. In the bogs, samples were taken along the environmental gradient from drier margins towards wetter central parts. A chiral column was used to gain insight into the variation in terpene composition. We hypothesized that terpene contents increase and the composition becomes more diverse in more strongly N-limited sites (greater C/N ratio) and that terpene signatures cluster together in sub-sites with similar conditions (drier/wetter). Altogether 37 terpenes were quantified across the sites. Extremely large variability of terpene contents, 48-62% for monoterpenes and 61-89% for sesquiterpenes, was observed. According to the amounts of a-pinenes and (+)-3-carene, we distinguished two different 'pine chemotypes'. Contrary to the hypothesis, terpene contents and variability were the greatest in the dry site with the lowest C/N ratio. However, individual terpenoids correlated differently with C or N in different sites, indicating site effects on terpene composition. Moreover, correlations between the terpenoids and C or N depended on the pine chemotype. The sub-sites with different water regime were more strongly clustered together within the site than across the sites. The study demonstrates extensive variations in terpene contents and composition among the populations and over short spatial distances within the populations, suggesting a large among- and withinpopulation adaptive capacity of P. sylvestris. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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18. Influence of nine antibiotics on key secondary metabolites and physiological characteristics in Triticum aestivum: Leaf volatiles as a promising new tool to assess toxicity.
- Author
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Opriş, Ocsana, Copaciu, Florina, Loredana Soran, Maria, Ristoiu, Dumitru, Niinemets, Ülo, and Copolovici, Lucian
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EFFECT of antibiotics on plants ,PLANT metabolites ,WHEAT ,VOLATILE organic compounds ,REGULATION of photosynthesis ,PHOTOSYNTHETIC pigments ,COMPOSITION of leaves ,PLANT assimilation ,ELECTRON transport ,LIPOXYGENASES ,MONOTERPENES ,DRUG pollution of water ,PHYSIOLOGY ,PLANTS - Abstract
Abstract: Extensive worldwide use of antibiotics has resulted in significant diffuse pollution of antibiotics in environment, but understanding the effects of many important antibiotics on plant physiological activity is still limited, especially at realistic environmental concentrations of antibiotics. To gain insight into influences of different antibiotics on plant performance and identify the most promising traits for fast assessment of toxicity, we studied impacts of nine antibiotics (amoxicillin, ampicillin, penicillin G, ceftazidime, ceftriaxone, tetracycline, doxycycline, ciprofloxacin and erythromycin) on foliage photosynthesis, photosynthetic pigment content and emissions of secondary volatile metabolites in wheat (Triticum aestivum L. cv. “Lovrin”). The antibiotics were applied at concentrations of 0.5mgL
−1 or 1.5mgL−1 either by watering for one week (0.5L solution) or for two weeks (1L solution) with given solution. Net assimilation rate was inhibited most strongly by ciprofloxacin and cephalosporins, but the inhibition was mainly due to reductions in stomatal conductance. Photosynthetic electron transport rate was affected by penicillins, cephalosporins and tetracyclines. Contents of photosynthetic pigments, chlorophylls and carotenoids, were most strongly reduced in treatments with tetracyclines, ciprofloxacin and erythromycin. The magnitude of plant photosynthetic and pigment responses generally increased with increasing the antibiotics’ dose, but the overall effects were moderate, 10–20 percent in most cases. Emissions of the lipoxygenase pathway products (LOX, green leaf volatiles) were most sensitive indicators of antibiotic treatments. LOX emissions were increased by five to six fold in response to antibiotic treatments and the emissions were quantitatively associated with the treatment dose. Monoterpene emissions were also strongly enhanced by antibiotic treatments, but the dose dependence was weaker. These data collectively suggest that analysis of leaf volatiles can provide a novel sensitive assay to gauge the toxicity of different antibiotics. [Copyright &y& Elsevier]- Published
- 2013
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19. Volatile Emissions from Alnus glutionosa Induced by Herbivory are Quantitatively Related to the Extent of Damage.
- Author
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Copolovic, Lucian, Kännaste, Astrid, Remmel, Triinu, Vislap, Vivian, and Niinemets, Ülo
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VOLATILE organic compounds ,GASES from plants ,PLANT photorespiration ,MONOTERPENES ,INSECTS ,HERBIVORES - Abstract
Plant volatile organic compounds (VOCs) elicited in response to herbivory serve as cues for parasitic and predatory insects. Knowledge about quantitative relationships between the extent of herbivore-induced damage and the quantities of VOCs released is scarce. We studied the kinetics of VOC-emissions from foliage of the deciduous tree Alnus glutinosa induced by feeding activity of larvae of the geometrid moth Cabera pusaria. Quantitative relationships between the intensity of stress and strength of plant response were determined. Intensity of biotic stress was characterized by herbivore numbers (0-8 larvae) and by the amount of leaf area eaten. The strength of plant response was characterized by monitoring (i) changes in photosynthesis, (ii) leaf ultrastructure, and (iii) plant volatiles. Net assimilation rate displayed compensatory responses in herbivore-damaged leaves compared with control leaves. This compensatory response was associated with an overall increase in chloroplast size. Feeding-induced emissions of products of the lipoxygenase pathway (LOX products; ( E)-2-hexenal, ( Z)-3-hexenol, 1-hexanol, and ( Z)-3-hexenyl acetate) peaked at day 1 after larval feeding started, followed by an increase of emissions of ubiquitous monoterpenes peaking on days 2 and 3. The emission of the monoterpene ( E)-β-ocimene and of the nerolidol-derived homoterpene 4,8-dimethyl-nona-1,3,7-triene (DMNT) peaked on day 3. Furthermore, the emission kinetics of the sesquiterpene ( E,E)-α-farnesene tended to be biphasic with peaks on days 2 and 4 after start of larval feeding. Emission rates of the induced LOX products, of ( E)-β-ocimene and ( E,E)-α-farnesene were positively correlated with the number of larvae feeding. In contrast, the emission of DMNT was independent of the number of feeders. These data show quantitative relationships between the strength of herbivory and the emissions of LOX products and most of the terpenoids elicited in response to feeding. Thus, herbivory-elicited LOX products and terpenoid emissions may convey both quantitative and qualitative signals to antagonists of the herbivores. In contrast, our data suggest that the feeding-induced homoterpene DMNT conveys the information 'presence of herbivores' rather than information about the quantities of herbivores to predators and parasitoids. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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20. Measurement of volatile terpene emissions in 70 dominant vascular plant species in Hawaii: aliens emit more than natives.
- Author
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Llusi, Joan, Peñuelas, Josep, Sardans, Jordi, Owen, Susan M., and Niinemets, Ülo
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PLANT species ,PLANT invasions ,INTRODUCED plants - Abstract
Aim Alien plant invasion is prominent in the Hawaiian Islands. There are many factors involved in invader success. To date, there is a general lack of information about one of them, which we aim to study here: the terpene emission capacity of both Hawaiian native and alien plants. Location Oahu (Hawaii). Methods We screened 35 alien and 35 native dominant plant species on Oahu Island for monoterpene emissions. The emission rates were measured from field-grown plants under standardized conditions of temperature and quantum flux density in the laboratory. Results The emission rates of total terpenes ranged from 0 µg g
−1 h−1 to 55 µg g−1 h−1 , and altogether 15 different terpenes were emitted in detectable amounts by the overall set of species. A phylogenetic signal was observed for total terpene emissions. Total terpene emission rates were higher in aliens than in native species (12.8 ± 2.0 vs. 7.6 ± 1.9 µg g−1 h−1 , respectively). Main conclusions The greater terpene emission capacity may confer protection against multiple stresses and may partly account for the success of the invasive species, and may make invasive species more competitive in response to new global change-driven combined stresses. These results are consistent with aliens coming from very diverse ecosystems with generally higher biotic and abiotic stress pressures, and having higher nutrient concentrations. On the contrary, these results are not consistent with the 'excess carbon' hypotheses. These results indicate changes in vegetation terpene emissions brought about by alien plant invasions. [ABSTRACT FROM AUTHOR]- Published
- 2010
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21. GAS CHROMATOGRAPHY-MASS SPECTROMETRY METHOD FOR DETERMINATION OF MONOTERPENE AND SESQUITERPENE EMISSIONS FROM STRESSED PLANTS.
- Author
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Copolovici, Lucian, Kännaste, Astrid, and Niinemets, Ülo
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MONOTERPENES ,TERPENES ,SESQUITERPENES ,GAS chromatography ,CHROMATOGRAPHIC analysis ,MASS spectrometry ,SPECTROMETRY ,SPECTRUM analysis - Abstract
Emissions of biogenic volatile organic compounds (BVOCs) play important roles in plant biology and atmospheric chemistry at a wide range of spatial and temporal scales. This article describes a headspace method coupled with gas chromatography - mass spectrometry (GC-MS) for the detection of volatile terpenes (monoterpenes and sesquiterpenes) and other related compounds emitted from plants, especially under stress conditions. A protocol is developed for simultaneous detection and quantification of isoprene, and mono- and sesquiterpenes from plant emissions. [ABSTRACT FROM AUTHOR]
- Published
- 2009
22. Salting-in and salting-out effects of ionic and neutral osmotica on limonene and linalool Henry’s law constants and octanol/water partition coefficients
- Author
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Copolovici, Lucian and Niinemets, Ülo
- Subjects
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MONOTERPENES , *HENRY'S law , *GLYCINE , *OCTYL alcohol , *ELECTROLYTES , *SORBITOL , *SUCROSE - Abstract
Foliar emission rates of plant-generated volatile monoterpenes depend on monoterpene partitioning between air, aqueous and lipid-phases in the leaves. While Henry’s law constants (H pc, equilibrium gas/water partition coefficient) and octanol/water partition coefficients (K OW) for pure water have been previously used to simulate monoterpene emissions from the leaves, aqueous phase in plants is a complex solution of electrolytes and neutral osmotica. We studied the effects of dissociated compounds KCl and glycine and sugars glucose, sorbitol and sucrose with concentrations between 0 and 1M on H pc and K OW values for limonene and linalool. Linalool with ca. 1500-fold lower H pc (2.62Pa m3 mol−1 for pure water at 30°C) and ca. 30-fold lower K OW (955molmol−1 for pure water at 25°C) is the more hydrophilic compound of the two monoterpenes. H pc of both monoterpenes increased with increasing concentration of both ionic compounds and sorbitol, but decreased with increasing glucose and sucrose concentrations. The salting-out coefficients for H pc (k H) were ca. an order of magnitude larger for more hydrophilic compound linalool than for more hydrophobic limonene. For linalool, co-solutes modified H pc by 30–50% at the highest concentration (1M) tested. The effect of temperature on the salting-out coefficient of KCl was minor. As with H pc, K OW increased with increasing the concentration of KCl, glycine and sorbitol, and decreased with increasing glucose and sucrose concentrations. For limonene, co-solutes modified K OW by 20–50% at the highest concentration used. For linalool, the corresponding range was 10–35%. Salting-out coefficients for H pc and K OW were correlated, but the lipid–solubility was more strongly affected than aqueous solubility in the case of limonene. Overall, these data demonstrate physiologically important effects of co-solutes on H pc and K OW for hydrophilic monoterpenes and on K OW for hydrophobic monoterpenes that should be included in current emission models. [Copyright &y& Elsevier]
- Published
- 2007
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23. Temperature dependencies of Henry’s law constants and octanol/water partition coefficients for key plant volatile monoterpenoids
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Copolovici, Lucian O. and Niinemets, Ülo
- Subjects
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MONOTERPENES , *TERPENES , *EMISSIONS (Air pollution) , *AIR pollution , *HENRY'S law , *ENTHALPY - Abstract
Abstract: To model the emission dynamics and changes in fractional composition of monoterpenoids from plant leaves, temperature dependencies of equilibrium coefficients must be known. Henry’s law constants (H pc, Pam3 mol−1 and octanol/water partition coefficients (K OW, molmol−1) were determined for 10 important plant monoterpenes at physiological temperature ranges (25–50°C for H pc and 20–50°C for K OW). A standard EPICS procedure was established to determine H pc and a shake flask method was used for the measurements of K OW. The enthalpy of volatilization (ΔH vol) varied from 18.0 to 44.3kJmol−1 among the monoterpenes, corresponding to a range of temperature-dependent increase in H pc between 1.3- and 1.8-fold per 10°C rise in temperature. The enthalpy of water–octanol phase change varied from −11.0 to −23.8kJmol−1, corresponding to a decrease of K OW between 1.15- and 1.32-fold per 10°C increase in temperature. Correlations among physico-chemical characteristics of a wide range of monoterpenes were analyzed to seek the ways of derivation of H pc and K OW values from other monoterpene physico-chemical characteristics. H pc was strongly correlated with monoterpene saturated vapor pressure (P v), and for lipophilic monoterpenes, ΔH vol scaled positively with the enthalpy of vaporization that characterizes the temperature dependence of P v Thus, P v versus temperature relations may be employed to derive the temperature relations of H pc for these monoterpenes. These data collectively indicate that monoterpene differences in H pc and K OW temperature relations can importantly modify monoterpene emissions from and deposition on plant leaves. [Copyright &y& Elsevier]
- Published
- 2005
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24. Induced Volatile Emissions, Photosynthetic Characteristics, and Pigment Content in Juglans regia Leaves Infected with the Erineum-Forming Mite Aceria erinea.
- Author
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Popitanu, Corina, Lupitu, Andreea, Copolovici, Lucian, Bungău, Simona, Niinemets, Ülo, and Copolovici, Dana Maria
- Subjects
ENGLISH walnut ,MITES ,VOLATILE organic compounds ,MONOTERPENES ,CHLOROPHYLL spectra ,ERIOPHYIDAE ,LEAF area - Abstract
Persian walnut (Juglans regia L., Juglandaceae), one of the essential nut crops, is affected by different diseases, including mite attacks which result in gall and erineum formation. As the proportion of leaf area covered by mite galls or erineum is typically relatively low, the impact on tree photosynthetic productivity is often considered minor, and no pest control management is usually suggested. However, the effect of erineum-forming mites on walnut photosynthesis might be disproportionately larger than can be predicted from the leaf area impacted. In the present study, we studied how the foliage photosynthetic characteristics, pigment contents, and stress-induced volatile organic compounds scaled with the severity of infection varied from 0% (control trees) to 9.9%, by erineum-forming mite Aceria erinea in J. regia. Both leaf net assimilation rate (up to 75% reduction) and stomatal conductance (up to 82%) decreased disproportionately, increasing infection severity. Leaf total chlorophyll and β-carotene contents also decreased with infection severity, although the reduction was less than for photosynthetic characteristics (28% for chlorophyll and 25% for β-carotene). The infection induced significant emissions of green leaves volatiles ((Z)-3-hexenol, (E)-2-hexenal, (Z)-3-hexenyl acetate and 1-hexanol), monoterpenes and the homoterpene 3-(E)-4,8-dimethyl-1,3,7-nonatriene, and these emissions scaled positively with the percentage of leaf area infected. These results collectively indicate that erineum-forming mite infection of walnut leaves results in profound modifications in foliage physiological characteristics that can significantly impact tree photosynthetic productivity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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25. The importance of sesquiterpene oxidation products for secondary organic aerosol formation in a springtime hemiboreal forest
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Barreira, Luis M. F., Ylisirniö, Arttu, Pullinen, Iida, Buchholz, Angela, Li, Zijun, Lipp, Helina, Junninen, Heikki, Hõrrak, Urmas, Noe, Steffen M., Krasnova, Alisa, Krasnov, Dmitrii, Kask, Kaia, Talts, Eero, Niinemets, Ülo, Ruiz-Jimenez, Jose, Schobesberger, Siegfried, Department of Chemistry, and Institute for Atmospheric and Earth System Research (INAR)
- Subjects
MOLECULES ,BOREAL ,ALPHA-PINENE OZONOLYSIS ,MASS-SPECTROMETER ,GAS ,116 Chemical sciences ,PARTICLES ,VOLATILITY BASIS-SET ,MONOTERPENES ,ATMOSPHERIC CHEMISTRY ,behavioral disciplines and activities ,EMISSIONS - Abstract
Secondary organic aerosols (SOAs) formed from biogenic volatile organic compounds (BVOCs) constitute a significant fraction of atmospheric particulate matter and have been recognized to significantly affect the climate and air quality. Atmospheric SOA particulate mass yields and chemical composition result from a complex mixture of oxidation products originating from a diversity of BVOCs. Many laboratory and field experiments have studied SOA particle formation and growth in the recent years. However, a large uncertainty still remains regarding the contribution of BVOCs to SOA. In particular, organic compounds formed from sesquiterpenes have not been thoroughly investigated, and their contribution to SOA remains poorly characterized. In this study, a Filter Inlet for Gases and Aerosols (FI-GAERO) combined with a high-resolution time-of-flight chemical ionization mass spectrometer (CIMS), with iodide ionization, was used for the simultaneous measurement of gas-phase and particle-phase oxygenated compounds. The aim of the study was to evaluate the relative contribution of sesquiterpene oxidation products to SOA in a springtime hemiboreal forest environment. Our results revealed that monoterpene and sesquiterpene oxidation products were the main contributors to SOA particles. The chemical composition of SOA particles was compared for times when either monoterpene or sesquiterpene oxidation products were dominant and possible key oxidation products for SOA particle formation were identified for both situations. Surprisingly, sesquiterpene oxidation products were the predominant fraction in the particle phase in some periods, while their gas-phase concentrations remained much lower than those of monoterpene products. This can be explained by favorable and effective partitioning of sesquiterpene products into the particle phase. The SOA particle volatility determined from measured thermograms increased when the concentration of sesquiterpene oxidation products in SOA particles was higher than that of monoterpenes. Overall, this study demonstrates that sesquiterpenes may have an important role in atmospheric SOA formation and oxidation chemistry, in particular during the spring recovery period.
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26. Impact of heat priming on heat shock responses in Origanum vulgare: Enhanced foliage photosynthetic tolerance and biphasic emissions of volatiles.
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Sulaiman, Hassan Yusuf, Liu, Bin, Abiola, Yusuph Olawale, Kaurilind, Eve, and Niinemets, Ülo
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- *
OREGANO , *PHOTOSYNTHETIC rates , *PHYSIOLOGICAL stress , *AROMATIC plants , *HEAT waves (Meteorology) , *SESQUITERPENES - Abstract
Climate change enhances the frequency of heatwaves that negatively affect photosynthesis and can alter constitutive volatile emissions and elicit emissions of stress volatiles, but how pre-exposure to mildly warmer temperatures affects plant physiological responses to subsequent severe heat episodes remains unclear, especially for aromatic plants with high and complex volatile defenses. We studied the impact of heat shock (45 °C/5 min) applied alone and after exposure to moderate heat stress (35 °C/1 h, priming) on foliage photosynthesis and volatile emissions in the aromatic plant Origanum vulgare through 72 h recovery period. Heat stress decreased photosynthesis rates and stomatal conductance, whereas the reductions in photosynthesis were primarily due to non-stomatal factors. In non-primed plants, heat shock-induced reductions in photosynthetic activity were the greatest, but photosynthetic activity completely recovered by the end of the experiment. In primed plants, a certain inhibition of photosynthetic activity remained, suggesting a sustained priming effect. Heat shock enhanced the emissions of volatiles including lipoxygenase pathway volatiles, long-chained fatty acid-derived compounds, mono- and sesquiterpenes, geranylgeranyl diphosphate pathway volatiles, and benzenoids, whereas different heat treatments resulted in unique emission blends. In non-primed plants, stress-elicited emissions recovered at 72 h. In primed plants, volatile emissions were multiphasic, the first phase, between 0.5 and 10 h, reflected the primary stress response, whereas the secondary rise, between 24 and 72 h, indicated activations of different defense metabolic pathways. Our results demonstrate that exposure to mild heat leads to a sustained physiological stress memory that enhances plant resistance to subsequent severe heat stress episodes. • Heat stress decreased leaf photosynthesis via non-stomatal factors. • Photosynthetic reductions were lower in plants pre-exposed to mild heat (priming). • Heat stress enhanced volatile emissions differently in primed and non-primed plants. • Volatile emissions recovered earlier in primed plants but later rose again. • Priming improves resistance and acclimation during subsequent severe heat stress. [ABSTRACT FROM AUTHOR]
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- 2023
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27. Screening Study of Leaf Terpene Concentration of 75 Borneo Rainforest Plant Species: Relationships with Leaf Elemental Concentrations and Morphology.
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Sardans, Jordi, Llusia, Joan, Owen, Susan M., Niinemets, Ülo, and Peñuelas, Josep
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LEAF morphology , *TERPENES , *RAIN forests , *PLANT species , *PLANT protection , *ABIOTIC stress - Abstract
Terpenes confer advantage in plant protection against abiotic stresses such as heat and drought and biotic stresses such as herbivore and pathogen attack. We conducted a screening of leaf mono- and sesquiterpene concentrations in 75 common woody plant species in the rainforest of Danum Valley (Borneo). Terpene compounds were found in 73 out of the 75 analysed species. Similar or lower proportions have been reported in other parts of the world. To our knowledge, this study reports for the first time the foliar concentration of mono- and/or sesquiterpene for 71 species and 39 genera not previously analyzed. Altogether 80 terpene compounds were determined across the species, and out of these only linalool oxide and (E)-γ-bisabolene had phylogenetic signal. A significant negative relationship between leaf monoterpene concentration and leaf length was observed, but leaf mono- and sesquitepene concentration were not related to any other leaf morphological trait nor to leaf elemental composition. Functions such as temperature protection, radiation protection or signaling and communication could underlie the high frequency of terpene-containing species of this tropical ecosystem which has multiple and very diverse interactions among multiple species. [ABSTRACT FROM AUTHOR]
- Published
- 2015
28. Isoprenoid emissions, photosynthesis and mesophyll diffusion conductance in response to blue light.
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Pallozzi, Emanuele, Tsonev, Tsonko, Marino, Giovanni, Copolovici, Lucian, Niinemets, Ülo, Loreto, Francesco, and Centritto, Mauro
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ISOPENTENOIDS , *PHOTOSYNTHESIS , *MESOPHYLL tissue , *EFFECT of blue light on plants , *STOMATA , *MONOTERPENES - Abstract
Highlights: [•] The negative effect of blue light on photosynthesis was particularly strong in species with higher photosynthetic rates. [•] The inhibition of photosynthesis involved coordinated reductions in stomatal and mesophyll conductance. [•] Blue light negatively affected isoprene and monoterpene emissions in concert with photosynthetic inhibition. [•] Both isoprene and monoterpene emissions were shown to be inversely dependent upon intercellular [CO2]. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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29. Emissions of green leaf volatiles and terpenoids from Solanum lycopersicum are quantitatively related to the severity of cold and heat shock treatments
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Copolovici, Lucian, Kännaste, Astrid, Pazouki, Leila, and Niinemets, Ülo
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TERPENES , *TOMATOES , *COLD (Temperature) , *HEAT , *QUANTITATIVE research , *EFFECT of stress on plant populations , *LIPOXYGENASES , *PLANT physiology - Abstract
Abstract: Plant-generated volatiles constitute a sensitive signal of stress response, but quantitative relationships between the stress severity and volatile emissions have been demonstrated only for a few stresses. Among important stresses in the field, chilling and frost stress in spring and heat stress mid-season can significantly curb productivity. We studied the effects of cold and heat shock treatments on leaf photosynthesis and the emission of the volatile products of the lipoxygenase pathway (LOX, also called green leaf volatiles) and mono- and sesquiterpene emissions in tomato (Solanum lycopersicum cv. Mato) to gain quantitative insights into temperature stress-elicited volatile emissions. Both cold and heat stress treatments ranged from mild, which only weakly affected foliage photosynthesis, to severe, which almost completely inhibited photosynthesis. Under non-stressed conditions, LOX emissions were close to the detection limit, and terpene emissions were low. Both cold and heat stress led to enhancement of LOX emissions according to a switch-type response with essentially no emissions under mild stress and major emissions under severe stress. The emissions of mono- and sesquiterpenes increased gradually with the severity of stress, but cold stress resulted in higher sesquiterpene emissions at any given monoterpene emission level. We suggest that the quantitative relationships between the stress strength and emissions observed in this study provide an important means to characterize the severity of cold and heat stresses. [Copyright &y& Elsevier]
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- 2012
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30. Emissions of monoterpenes linalool and ocimene respond differently to environmental changes due to differences in physico-chemical characteristics
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Noe, Steffen M., Ciccioli, Paolo, Brancaleoni, Enzo, Loreto, Francesco, and Niinemets, Ülo
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- *
MONOTERPENES , *WATER laws , *TERPENES , *OCTYL alcohol - Abstract
Abstract: We investigated the 13C-labeling kinetics of the emission of two major monoterpenes emitted by needles of Mediterranean conifer Pinus pinea L., monoterpene alcohol linalool and non-oxygenated monoterpene trans-β-ocimene. These data were further used to develop and parameterize a dynamics monoterpene emission model, predicting the emissions of monoterpenes with contrasting physico-chemical properties to environmental changes. All monoterpenes emitted were labeled by 13C in short pulse-labeling experiments. 13C-labeling experiments further indicated for these two monoterpenes comprising 77% of total emissions that a major part of the emissions of these two monoterpenes relied on recently synthesized carbon not on specific storage compartments within the resin ducts. However, labeling kinetics suggested existence of transient storage pools, located within the needle aqueous and lipid phases. For linalool, we found half-lives of 13min for the aqueous phase storage and 3h for the lipid phase while trans-β-ocimene exhibit an aqueous phase half-life of 2 and 15min for the lipid phase, overall indicating that the transient storage due to limited monoterpene volatility can significantly alter the emission dynamics. The key physico-chemical characteristics determining the time constants of the transient storage pools were the Henry''s law constant (liquid/gas phase partition coefficient) and the octanol/water (lipid/liquid) phase partition coefficient. As monoterpene Henry''s law constants vary over four orders of magnitude and octanol/water partition coefficients over three orders of magnitude, the capacity for non-specific storage, and damping of the effects of rapidly changing environmental conditions is expected to strongly vary among different monoterpenes. Overall, our study suggests that non-specific storage due to limited volatility is a common phenomenon of common of plant-emitted compounds. [Copyright &y& Elsevier]
- Published
- 2006
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31. Foliage inoculation by Burkholderia vietnamiensis CBMB40 antagonizes methyl jasmonate-mediated stress in Eucalyptus grandis.
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Kanagendran, Arooran, Chatterjee, Poulami, Liu, Bin, Sa, Tongmin, Pazouki, Leila, and Niinemets, Ülo
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- *
EUCALYPTUS grandis , *ENDOPHYTIC bacteria , *BURKHOLDERIA , *SECONDARY metabolism , *METABOLISM , *PLANT growth - Abstract
Methyl jasmonate (MeJA) is widely used as a model chemical to study hypersensitive responses to biotic stress impacts in plants. Elevated levels of methyl jasmonate induce jasmonate-dependent defense responses, associated with a decline in primary metabolism and enhancement of secondary metabolism of plants. However, there is no information of how stress resistance of plants, and accordingly the sensitivity to exogenous MeJA can be decreased by endophytic plant growth promoting rhizobacteria (PGPR) harboring ACC (1-aminocyclopropane-1-carboxylate) deaminase. In this study, we estimated stress alleviating potential of endophytic PGPR against MeJA-induced plant perturbations through assessing photosynthetic traits and stress volatile emissions. We used mild (5 mM) to severe (20 mM) MeJA and endophytic plant growth promoting rhizobacteria Burkholderia vietnamiensis CBMB40 and studied how MeJA and B. vietnamiensis treatments influenced temporal changes in photosynthetic characteristics and stress volatile emissions. Separate application of MeJA markedly decreased photosynthetic characteristics and increased lipoxygenase pathway (LOX) volatiles, volatile isoprenoids, saturated aldehydes, lightweight oxygenated compounds (LOC), geranyl-geranyl diphosphate pathway (GGDP) volatiles, and benzenoids. However, MeJA-treated leaves inoculated by endophytic bacteria B. vietnamiensis had substantially increased photosynthetic characteristics and decreased emissions of LOX, volatile isoprenoids and other stress volatiles compared with non-inoculated MeJA treatments, especially at later stages of recovery. In addition, analysis of leaf terpenoid contents demonstrated that several mono- and sesquiterpenes were de novo synthesized upon MeJA and B. vietnamiensis applications. This study demonstrates that foliar application of endophytic bacteria B. vietnamiensis can potentially enhance resistance to biotic stresses and contribute to the maintenance of the integrity of plant metabolic activity. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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