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Jarmo K Holopainen - One of the best experts on this subject based on the ideXlab platform.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 � C) while daytime temperature was kept at a constant 22 � C. VOC emissions were collected during the daytime and analysed by gas chromatography–mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and b-ocimene increased from 6 � Ct o 14� C, while several other monoterpenes and the SQTs (Z,E)-a-farnesene and (E,E)-a-farnesene increased up to 18 � C. Total monoterpene and sesquiterpene emission peaked at 18 � C, whereas isoprene emissions decreased at 22 � C. Leaf area increased across the temperature range of 6–22 � C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 degrees C) while daytime temperature was kept at a constant 22 degrees C. VOC emissions were collected during the daytime and analysed by gas chromatography-mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and beta-ocimene increased from 6 degrees C to 14 degrees C, while several other monoterpenes and the SQTs (Z,E)-alpha-farnesene and (E,E)-alpha-farnesene increased up to 18 degrees C. Total monoterpene and sesquiterpene emission peaked at 18 degrees C, whereas isoprene emissions decreased at 22 degrees C. Leaf area increased across the temperature range of 6-22 degrees C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.
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emission of herbivore induced volatile terpenoids from two hybrid aspen Populus tremula tremuloides clones under ambient and elevated ozone concentrations in the field
Global Change Biology, 2007Co-Authors: James D Blande, Elina Oksanen, Paivi Tiiva, Jarmo K HolopainenAbstract:Tropospheric ozone levels are continuously rising due to human activities in the 21st century. Although the phytotoxic impact of ozone on plants has been well documented, the effect of ozone on plant emissions has received little attention. We have conducted a field-based investigation utilizing two clones of hybrid aspen (Populus tremula L. ×P. tremuloides Michx.) in a free-air ozone concentration enrichment (FACE) facility. The effects of chronic exposure to moderately increased concentrations of ozone on insect-induced terpene emissions by these trees were investigated. We used two herbivore species, Phyllobius piri, and Epirrita autumnata, both of which can reach outbreak levels on deciduous trees in Northern Europe. Our results indicated only very small changes in emissions due to increased ozone levels, but showed induction of some terpenes, particularly the monoterpene trans-β-ocimene and the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene, in response to insect feeding. Here, we consider the positive aspects of conducting this type of study in the field and consider the possible influences of other field-based environmental factors.
Matti Rousi - One of the best experts on this subject based on the ideXlab platform.
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adaptability of birch betula pendula roth and aspen Populus tremula l genotypes to different soil moisture conditions
Forest Ecology and Management, 2011Co-Authors: Boy J H M Possen, Matti Rousi, Elina Oksanen, Arja Tervahauta, Sirpa Karenlampi, Hanna Ruhanen, Viivi Ahonen, Jaakko Heinonen, Juha Heiskanen, Elina VapaavuoriAbstract:Abstract For northern Europe’s climate, models predict an increase in periods of drought and waterlogging. Knowledge of variation between genotypes of Betula pendula (birch) and Populus tremula (aspen) to drought and excess soil moisture are unavailable but relevant for future development of forest ecosystems. We studied variation between genotypes to soil moisture in birch and aspen with plant material representing naturally regenerated populations and showed differences in acclimation to soil moisture conditions. Genotypes showing most growth and biomass accumulation across treatments maintained most leaf area, high gas exchange and water-use efficiency and grew most root mass but had the lowest root length per unit root dry mass compared to other genotypes. This indicates that these genotypes are more efficient in harvesting water from the soil under adverse conditions. We also showed that birch and aspen employ different strategies to cope with soil moisture conditions, with aspen investing more in perennial parts, while birch efficiently maintains foliar processes. When the expression of some known drought responsive genes was measured, only ACC oxidase was induced by the drought treatment at the beginning of the experiment, while surprisingly LEA5 , RD22 and ADH1 did not respond to drought, but were up-regulated in prolonged wet conditions indicating oxidative stress and hypoxia and that these genes are responding to multiple stress factors. We conclude that in plants micro-propagated from naturally regenerated birch and aspen populations, there is variation between genotypes in acclimation efficiency to soil moisture conditions.
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vertical profiles reveal impact of ozone and temperature on carbon assimilation of betula pendula and Populus tremula
Tree Physiology, 2011Co-Authors: Maarit Maenpaa, Johanna Riikonen, Sari Kontunensoppela, Matti Rousi, Elina OksanenAbstract:Rising temperature and tropospheric ozone (O3) concentrations are likely to affect carbon assimilation processes and thus the carbon sink strength of trees. In this study, we investigated the joint action of elevated ozone and temperature on silver birch (Betula pendula) and European aspen (Populus tremula) saplings in field conditions by combining free-air ozone exposure (1.2 × ambient) and infrared heaters (ambient +1.2 °C). At leaf level measurements, elevated ozone decreased leaf net photosynthesis (Pn), while the response to elevated temperature was dependent on leaf position within the foliage. This indicates that leaf position has to be taken into account when leaf level data are collected and applied. The ozone effect on Pn was partly compensated for at elevated temperature, showing an interactive effect of the treatments. In addition, the ratio of photosynthesis to stomatal conductance (Pn/gs ratio) was decreased by ozone, which suggests decreasing water use efficiency. At the plant level, the increasing leaf area at elevated temperature resulted in a considerable increase in photosynthesis and growth in both species.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 � C) while daytime temperature was kept at a constant 22 � C. VOC emissions were collected during the daytime and analysed by gas chromatography–mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and b-ocimene increased from 6 � Ct o 14� C, while several other monoterpenes and the SQTs (Z,E)-a-farnesene and (E,E)-a-farnesene increased up to 18 � C. Total monoterpene and sesquiterpene emission peaked at 18 � C, whereas isoprene emissions decreased at 22 � C. Leaf area increased across the temperature range of 6–22 � C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 degrees C) while daytime temperature was kept at a constant 22 degrees C. VOC emissions were collected during the daytime and analysed by gas chromatography-mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and beta-ocimene increased from 6 degrees C to 14 degrees C, while several other monoterpenes and the SQTs (Z,E)-alpha-farnesene and (E,E)-alpha-farnesene increased up to 18 degrees C. Total monoterpene and sesquiterpene emission peaked at 18 degrees C, whereas isoprene emissions decreased at 22 degrees C. Leaf area increased across the temperature range of 6-22 degrees C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.
Heinz Rennenberg - One of the best experts on this subject based on the ideXlab platform.
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lead uptake increases drought tolerance of wild type and transgenic poplar Populus tremula x p alba overexpressing gsh 1
Environmental Pollution, 2016Co-Authors: Sladjana Samuilov, Friedericke Lang, Matilda Djukic, Danijela Djunisijevicbojovic, Heinz RennenbergAbstract:Growth and development of plants largely depends on their adaptation ability in a changing climate. This is particularly true on heavy metal contaminated soils, but the interaction of heavy metal stress and climate on plant performance has not been intensively investigated. The aim of the present study was to elucidate if transgenic poplars (Populus tremula x P. alba) with enhanced glutathione content possess an enhanced tolerance to drought and lead (Pb) exposure (single and in combination) and if they are good candidates for phytoremediation of Pb contaminated soil. Lead exposure reduced growth and biomass accumulation only in above-ground tissue of wild type poplar, although most of lead accumulated in the roots. Drought caused a decline of the water content rather than reduced biomass production, while Pb counteracted this decline in the combined exposure. Apparently, metals such as Pb possess a protective function against drought, because they interact with abscisic acid dependent stomatal closure. Lead exposure decreased while drought increased glutathione content in leaves of both plant types. Lead accumulation was higher in the roots of transgenic plants, presumably as a result of chelation by glutathione. Water deprivation enhanced Pb accumulation in the roots, but Pb was subject to leakage out of the roots after re-watering. Transgenic plants showed better adaptation under mild drought plus Pb exposure partially due to improved glutathione synthesis. However, the transgenic plants cannot be considered as a good candidate for phytoremediation of Pb, due to its small translocation to the shoots and its leakage out of the roots upon re-watering.
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interaction of nitrogen nutrition and salinity in grey poplar Populus tremula x alba
Plant Cell and Environment, 2007Co-Authors: Barbara Ehlting, P Dluzniewska, Henriette Dietrich, Anita Selle, Markus Teuber, Robert Hansch, Jörg-peter Schnitzler, Uwe Nehls, Andrea Polle, Heinz RennenbergAbstract:: Salinity represents an increasing environmental problem in managed ecosystems. Populus spp. is widely used for wood production by short-rotation forestry in fertilized plantations and can be grown on saline soil. Because N fertilization plays an important role in salt tolerance, we analysed Grey poplar (Populus tremula x alba, syn. Populus canescens) grown with either 1 mM nitrate or ammonium subjected to moderate 75 mM NaCl. The impact of N nutrition on amelioration of salt tolerance was analysed on different levels of N metabolism such as N uptake, assimilation and N (total N, proteins and amino compounds) accumulation. Na concentration increased in all tissues over time of salt exposure. The N nutrition-dependent effects of salt exposure were more intensive in roots than in leaves. Application of salt reduced root increment as well as stem height increase and, at the same time, increased the concentration of total amino compounds more intensively in roots of ammonium-fed plants. In leaves, salt treatment increased concentrations of total N more intensively in nitrate-fed plants and concentrations of amino compounds independently of N nutrition. The major changes in N metabolism of Grey poplar exposed to moderate salt concentrations were detected in the significant increase of amino acid concentrations. The present results indicate that N metabolism of Grey poplar exposed to salt performed better when the plants were fed with nitrate instead of ammonium as sole N source. Therefore, nitrate fertilization of poplar plantations grown on saline soil should be preferred.
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regulation of sulphate assimilation by glutathione in poplars Populus tremula p alba of wild type and overexpressing γ glutamylcysteine synthetase in the cytosol
Journal of Experimental Botany, 2004Co-Authors: Tanja Nicole Hartmann, Heinz Rennenberg, Markus Wirtz, Petra Honicke, Rudiger Hell, Stanislav KoprivaAbstract:: Glutathione (GSH) is the major low molecular weight thiol in plants with different functions in stress defence and the transport and storage of sulphur. Its synthesis is dependent on the supply of its constituent amino acids cysteine, glutamate, and glycine. GSH is a feedback inhibitor of the sulphate assimilation pathway, the primary source of cysteine synthesis. Sulphate assimilation has been analysed in transgenic poplars (Populus tremula x P. alba) overexpressing gamma-glutamylcysteine synthetase, the key enzyme of GSH synthesis, and the results compared with the effects of exogenously added GSH. Although foliar GSH levels were 3-4-fold increased in the transgenic plants, the activities of enzymes of sulphate assimilation, namely ATP sulphurylase, adenosine 5'-phosphosulphate reductase (APR), sulphite reductase, serine acetyltransferase, and O-acetylserine (thiol)lyase were not affected in three transgenic lines compared with the wild type. Also the mRNA levels of these enzymes were not altered by the increased GSH levels. By contrast, an increase in GSH content due to exogenously supplied GSH resulted in a strong reduction in APR activity and mRNA accumulation. This feedback regulation was reverted by simultaneous addition of O-acetylserine (OAS). However, OAS measurements revealed that OAS cannot be the only signal responsible for the lack of feedback regulation of APR by GSH in the transgenic poplars.
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protection from paraquat mediated photo oxidative stress by glutathione in poplar Populus tremula p alba plants
Plant Biology, 2001Co-Authors: B Will, Lise Jouanin, Heinz RennenbergAbstract:: The sensitivity of hybrid poplar (Populus tremula×P. alba) to oxidative stress mediated by paraquat exposure was analysed with leaf discs from wild-type plants and plants expressing the bacterial cDNA of the enzymes of glutathione synthesis, namely gshI, encoding γ-glutamylcysteine synthetase (ECS), or gshII, encoding glutathione synthetase (GS), both in the cytosol. It was expected that leaf discs containing more than 2-fold elevated glutathione concentrations due to over-expression of ECS are less susceptible to paraquat exposure than wild-type plants and transformants over-expressing GS. However, neither over-expression of GS nor of ECS improved paraquat tolerance of the leaves. This result was surprising, because in wild-type plants reduced paraquat sensitivity of young compared with mature leaves coincided with ca. 30 % higher glutathione contents of the young leaves. Apparently, developmental changes in paraquat sensitivity of poplar leaves are controlled by factors different from glutathione contents. Feeding experiments with glutathione and its metabolic precursor γ-glutamylcysteine (EC) plus gly showed that glutathione can provide protection from paraquat-mediated photo-oxidative stress; but at least ca. 5-fold elevated glutathione levels are required for this effect in poplar leaves. Currently, such high glutathione levels have not been achieved by the application of plant molecular biology techniques. The significance of glutathione for the compensation of photo-oxidative stress is discussed.
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metabolic origin of acetaldehyde emitted by poplar Populus tremula p alba trees
Journal of Experimental Botany, 1999Co-Authors: Jurgen Kreuzwieser, Ursula Scheerer, Heinz RennenbergAbstract:The metabolic origin and emission by the leaves of the tropospheric trace gas acetaldehyde were examined in 4-month-old poplar trees (Populus tremula x P. alba) cultivated under controlled environmental conditions in a greenhouse. Treatments which resulted in increased ethanol concentration of the xylem sap caused significantly enhanced rates of acetaldehyde and ethanol emission by the leaves. Leaves fed [ 14 C]-ethanol via the transpiration stream emitted [ 14 C]-acetaldehyde. These findings suggest that acetaldehyde in the leaves is synthesized by a metabolic pathway that operates in the opposite direction of alcoholic fermentation and results in oxidation of ethanol. Enzymatic studies showed that this pathway is mediated either by alcohol dehydrogenase (ADH; EC 1.1.1.1) or catalase (CAT; EC 1.11.1.6), both constitutively present in the leaves of poplar trees. Labelling experiments with [ 14 C]-glucose indicated that the ethanol delivered to the leaves by the transpiration stream is produced in anaerobic zones of submersed roots by alcoholic fermentation. Anoxic conditions in the rhizosphere caused by flooding of the root system resulted in an activation of alcoholic fermentation and led to significantly increased ethanol concentrations in the xylem sap. These results support the hypothesis that acetaldehyde emitted by the leaves of trees is derived from xylem transported ethanol which is synthesized during alcoholic fermentation in the roots.
Maarit Maenpaa - One of the best experts on this subject based on the ideXlab platform.
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vertical profiles reveal impact of ozone and temperature on carbon assimilation of betula pendula and Populus tremula
Tree Physiology, 2011Co-Authors: Maarit Maenpaa, Johanna Riikonen, Sari Kontunensoppela, Matti Rousi, Elina OksanenAbstract:Rising temperature and tropospheric ozone (O3) concentrations are likely to affect carbon assimilation processes and thus the carbon sink strength of trees. In this study, we investigated the joint action of elevated ozone and temperature on silver birch (Betula pendula) and European aspen (Populus tremula) saplings in field conditions by combining free-air ozone exposure (1.2 × ambient) and infrared heaters (ambient +1.2 °C). At leaf level measurements, elevated ozone decreased leaf net photosynthesis (Pn), while the response to elevated temperature was dependent on leaf position within the foliage. This indicates that leaf position has to be taken into account when leaf level data are collected and applied. The ozone effect on Pn was partly compensated for at elevated temperature, showing an interactive effect of the treatments. In addition, the ratio of photosynthesis to stomatal conductance (Pn/gs ratio) was decreased by ozone, which suggests decreasing water use efficiency. At the plant level, the increasing leaf area at elevated temperature resulted in a considerable increase in photosynthesis and growth in both species.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 � C) while daytime temperature was kept at a constant 22 � C. VOC emissions were collected during the daytime and analysed by gas chromatography–mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and b-ocimene increased from 6 � Ct o 14� C, while several other monoterpenes and the SQTs (Z,E)-a-farnesene and (E,E)-a-farnesene increased up to 18 � C. Total monoterpene and sesquiterpene emission peaked at 18 � C, whereas isoprene emissions decreased at 22 � C. Leaf area increased across the temperature range of 6–22 � C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 degrees C) while daytime temperature was kept at a constant 22 degrees C. VOC emissions were collected during the daytime and analysed by gas chromatography-mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and beta-ocimene increased from 6 degrees C to 14 degrees C, while several other monoterpenes and the SQTs (Z,E)-alpha-farnesene and (E,E)-alpha-farnesene increased up to 18 degrees C. Total monoterpene and sesquiterpene emission peaked at 18 degrees C, whereas isoprene emissions decreased at 22 degrees C. Leaf area increased across the temperature range of 6-22 degrees C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.
Sirpa Karenlampi - One of the best experts on this subject based on the ideXlab platform.
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adaptability of birch betula pendula roth and aspen Populus tremula l genotypes to different soil moisture conditions
Forest Ecology and Management, 2011Co-Authors: Boy J H M Possen, Matti Rousi, Elina Oksanen, Arja Tervahauta, Sirpa Karenlampi, Hanna Ruhanen, Viivi Ahonen, Jaakko Heinonen, Juha Heiskanen, Elina VapaavuoriAbstract:Abstract For northern Europe’s climate, models predict an increase in periods of drought and waterlogging. Knowledge of variation between genotypes of Betula pendula (birch) and Populus tremula (aspen) to drought and excess soil moisture are unavailable but relevant for future development of forest ecosystems. We studied variation between genotypes to soil moisture in birch and aspen with plant material representing naturally regenerated populations and showed differences in acclimation to soil moisture conditions. Genotypes showing most growth and biomass accumulation across treatments maintained most leaf area, high gas exchange and water-use efficiency and grew most root mass but had the lowest root length per unit root dry mass compared to other genotypes. This indicates that these genotypes are more efficient in harvesting water from the soil under adverse conditions. We also showed that birch and aspen employ different strategies to cope with soil moisture conditions, with aspen investing more in perennial parts, while birch efficiently maintains foliar processes. When the expression of some known drought responsive genes was measured, only ACC oxidase was induced by the drought treatment at the beginning of the experiment, while surprisingly LEA5 , RD22 and ADH1 did not respond to drought, but were up-regulated in prolonged wet conditions indicating oxidative stress and hypoxia and that these genes are responding to multiple stress factors. We conclude that in plants micro-propagated from naturally regenerated birch and aspen populations, there is variation between genotypes in acclimation efficiency to soil moisture conditions.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 � C) while daytime temperature was kept at a constant 22 � C. VOC emissions were collected during the daytime and analysed by gas chromatography–mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and b-ocimene increased from 6 � Ct o 14� C, while several other monoterpenes and the SQTs (Z,E)-a-farnesene and (E,E)-a-farnesene increased up to 18 � C. Total monoterpene and sesquiterpene emission peaked at 18 � C, whereas isoprene emissions decreased at 22 � C. Leaf area increased across the temperature range of 6–22 � C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.
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elevation of night time temperature increases terpenoid emissions from betula pendula and Populus tremula
Journal of Experimental Botany, 2010Co-Authors: Mohamed A Ibrahim, Maarit Maenpaa, Sari Kontunensoppela, Matti Rousi, Viivi H Hassinen, Lukas Malec, Liisa Pietikainen, Arja Tervahauta, Sirpa Karenlampi, Jarmo K HolopainenAbstract:Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 degrees C) while daytime temperature was kept at a constant 22 degrees C. VOC emissions were collected during the daytime and analysed by gas chromatography-mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and beta-ocimene increased from 6 degrees C to 14 degrees C, while several other monoterpenes and the SQTs (Z,E)-alpha-farnesene and (E,E)-alpha-farnesene increased up to 18 degrees C. Total monoterpene and sesquiterpene emission peaked at 18 degrees C, whereas isoprene emissions decreased at 22 degrees C. Leaf area increased across the temperature range of 6-22 degrees C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees.