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Carlo Bicchi - One of the best experts on this subject based on the ideXlab platform.
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Headspace solid phase microextraction fast gc in combination with principal component analysis as a tool to classify different chemotypes of chamomile Flower Heads matricaria recutita l
Phytochemical Analysis, 2006Co-Authors: Patrizia Rubiolo, Flavio Belliardo, Chiara Cordero, Erica Liberto, Barbara Sgorbini, Carlo BicchiAbstract:Headspace–solid-phase microextraction gas chromatography-principal component analysis (HS-SPME GC-PCA) is proposed as a complementary or alternative method to essential oil (EO) GC-PCA in order to discriminate between Flower-Heads of chamomile of different chemotypes. Ninety-two EOs and the Headspaces sampled by HS-SPME of the corresponding chamomile Flower-Heads were examined by conventional GC and fast GC (F-GC) and the results submitted to statistical analysis by PCA. HS-SPME F-GC-PCA showed itself to be a rapid technique by which to distinguish chamomile Flower-Head chemotypes a produced results in agreement with the accepted EO classification. Using this method, the analysis time was reduced from at least 4.5 h with EO conventional GC to less than 1 h with HS-SPME F-GC. This approach can thus successfully be used as an analytical decision maker in order to reduce the number of time-consuming EO conventional GC analyses by limiting them to those samples that cannot unequivocally be classified. The EO conventional GC and HS-SPME F-GC results of PCA were very uniform, but they did not provide quantitative correlations between the components as determined by the two methods. A different statistical approach and a larger number of samples will be needed in order to correlate components in the Headspace sampled by SPME and those in the corresponding EO quantitatively through a function. Copyright © 2006 John Wiley & Sons, Ltd.
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Headspace solid phase microextraction fast gc in combination with principal component analysis as a tool to classify different chemotypes of chamomile Flower Heads matricaria recutita l
Phytochemical Analysis, 2006Co-Authors: Patrizia Rubiolo, Flavio Belliardo, Chiara Cordero, Erica Liberto, Barbara Sgorbini, Carlo BicchiAbstract:Headspace-solid-phase microextraction gas chromatography-principal component analysis (HS-SPME GC-PCA) is proposed as a complementary or alternative method to essential oil (EO) GC-PCA in order to discriminate between Flower-Heads of chamomile of different chemotypes. Ninety-two EOs and the Headspaces sampled by HS-SPME of the corresponding chamomile Flower-Heads were examined by conventional GC and fast GC (F-GC) and the results submitted to statistical analysis by PCA. HS-SPME F-GC-PCA showed itself to be a rapid technique by which to distinguish chamomile Flower-Head chemotypes a produced results in agreement with the accepted EO classification. Using this method, the analysis time was reduced from at least 4.5 h with EO conventional GC to less than 1 h with HS-SPME F-GC. This approach can thus successfully be used as an analytical decision maker in order to reduce the number of time-consuming EO conventional GC analyses by limiting them to those samples that cannot unequivocally be classified. The EO conventional GC and HS-SPME F-GC results of PCA were very uniform, but they did not provide quantitative correlations between the components as determined by the two methods. A different statistical approach and a larger number of samples will be needed in order to correlate components in the Headspace sampled by SPME and those in the corresponding EO quantitatively through a function.
Hyeonsook Cheong - One of the best experts on this subject based on the ideXlab platform.
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coordinated expression of cytosolic and chloroplastic glutamine synthetase during reproductive stage and its impact in gs1 rnai transgenic rice
Rice Science, 2018Co-Authors: Tieungoc Nguyen Le, Beomgi Lee, Kyoungwhan Back, Young Soon Kim, Hyeonsook CheongAbstract:Abstract To understand the reallocation of organic nitrogen from leaf to the Flower Head of rice, the role of glutamine synthetase (GS) was investigated by characterizing GS1 RNAi transgenic rice, which revealed a significant reduction in panicle number and number of seeds per panicle. We observed the expression of GS isotypes at transcriptional and protein levels in flag leaves, leaf sheaths and panicles at three different Flower development stages. The mRNA expression of GS1;1 was clearly suppressed in flag leaves, especially at the Flowering stage. GS1 protein was barely detectable in flag leaves until the Flowering stage, while GS1 protein was compromised in the leaf sheath and panicle, with transient expression of GS2 protein at the Flowering stage. The glutamine level in transgenic plants was significantly reduced in both flag leaves and panicles, but ammonium was highly accumulated. The level of other amino acids, including aspartate and asparagine, tended to be higher in RNAi transgenic plants than the wild type plants during the reproductive stage. In addition, accumulation of toxic ammonium in panicles with low glutamine level might have caused low seed-setting in the transgenic rice. These results indicated that nitrogen reallocation was critical for panicle development, and that multiple GS isotypes functioned cooperatively to complete the rice life cycle when leaf nitrogen was remobilized to the developing reproductive organs.
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Coordinated Expression of Cytosolic and Chloroplastic Glutamine Synthetase During Reproductive Stage and Its Impact in GS1 RNAi Transgenic Rice
Elsevier, 2018Co-Authors: Beomgi Lee, Kyoungwhan Back, Young Soon Kim, Hyeonsook CheongAbstract:To understand the reallocation of organic nitrogen from leaf to the Flower Head of rice, the role of glutamine synthetase (GS) was investigated by characterizing GS1 RNAi transgenic rice, which revealed a significant reduction in panicle number and number of seeds per panicle. We observed the expression of GS isotypes at transcriptional and protein levels in flag leaves, leaf sheaths and panicles at three different Flower development stages. The mRNA expression of GS1;1 was clearly suppressed in flag leaves, especially at the Flowering stage. GS1 protein was barely detectable in flag leaves until the Flowering stage, while GS1 protein was compromised in the leaf sheath and panicle, with transient expression of GS2 protein at the Flowering stage. The glutamine level in transgenic plants was significantly reduced in both flag leaves and panicles, but ammonium was highly accumulated. The level of other amino acids, including aspartate and asparagine, tended to be higher in RNAi transgenic plants than the wild type plants during the reproductive stage. In addition, accumulation of toxic ammonium in panicles with low glutamine level might have caused low seed-setting in the transgenic rice. These results indicated that nitrogen reallocation was critical for panicle development, and that multiple GS isotypes functioned cooperatively to complete the rice life cycle when leaf nitrogen was remobilized to the developing reproductive organs. Keywords: ammonium, grain yield, RNA interference, panicle development, nitrogen reallocation, rice, glutamine synthase, Flowering stag
Patrizia Rubiolo - One of the best experts on this subject based on the ideXlab platform.
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Headspace solid phase microextraction fast gc in combination with principal component analysis as a tool to classify different chemotypes of chamomile Flower Heads matricaria recutita l
Phytochemical Analysis, 2006Co-Authors: Patrizia Rubiolo, Flavio Belliardo, Chiara Cordero, Erica Liberto, Barbara Sgorbini, Carlo BicchiAbstract:Headspace–solid-phase microextraction gas chromatography-principal component analysis (HS-SPME GC-PCA) is proposed as a complementary or alternative method to essential oil (EO) GC-PCA in order to discriminate between Flower-Heads of chamomile of different chemotypes. Ninety-two EOs and the Headspaces sampled by HS-SPME of the corresponding chamomile Flower-Heads were examined by conventional GC and fast GC (F-GC) and the results submitted to statistical analysis by PCA. HS-SPME F-GC-PCA showed itself to be a rapid technique by which to distinguish chamomile Flower-Head chemotypes a produced results in agreement with the accepted EO classification. Using this method, the analysis time was reduced from at least 4.5 h with EO conventional GC to less than 1 h with HS-SPME F-GC. This approach can thus successfully be used as an analytical decision maker in order to reduce the number of time-consuming EO conventional GC analyses by limiting them to those samples that cannot unequivocally be classified. The EO conventional GC and HS-SPME F-GC results of PCA were very uniform, but they did not provide quantitative correlations between the components as determined by the two methods. A different statistical approach and a larger number of samples will be needed in order to correlate components in the Headspace sampled by SPME and those in the corresponding EO quantitatively through a function. Copyright © 2006 John Wiley & Sons, Ltd.
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Headspace solid phase microextraction fast gc in combination with principal component analysis as a tool to classify different chemotypes of chamomile Flower Heads matricaria recutita l
Phytochemical Analysis, 2006Co-Authors: Patrizia Rubiolo, Flavio Belliardo, Chiara Cordero, Erica Liberto, Barbara Sgorbini, Carlo BicchiAbstract:Headspace-solid-phase microextraction gas chromatography-principal component analysis (HS-SPME GC-PCA) is proposed as a complementary or alternative method to essential oil (EO) GC-PCA in order to discriminate between Flower-Heads of chamomile of different chemotypes. Ninety-two EOs and the Headspaces sampled by HS-SPME of the corresponding chamomile Flower-Heads were examined by conventional GC and fast GC (F-GC) and the results submitted to statistical analysis by PCA. HS-SPME F-GC-PCA showed itself to be a rapid technique by which to distinguish chamomile Flower-Head chemotypes a produced results in agreement with the accepted EO classification. Using this method, the analysis time was reduced from at least 4.5 h with EO conventional GC to less than 1 h with HS-SPME F-GC. This approach can thus successfully be used as an analytical decision maker in order to reduce the number of time-consuming EO conventional GC analyses by limiting them to those samples that cannot unequivocally be classified. The EO conventional GC and HS-SPME F-GC results of PCA were very uniform, but they did not provide quantitative correlations between the components as determined by the two methods. A different statistical approach and a larger number of samples will be needed in order to correlate components in the Headspace sampled by SPME and those in the corresponding EO quantitatively through a function.
Jurg Stocklin - One of the best experts on this subject based on the ideXlab platform.
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does pre dispersal seed predation limit reproduction and population growth in the alpine clonal plant geum reptans
Plant Ecology, 2006Co-Authors: Tina Weppler, Jurg StocklinAbstract:We studied the impact of the seed damaging gall midge larva Geomyia alpina on its perennial alpine host plant Geum reptans. We analysed the effect of seed predation on reproduction by seeds, i.e. seed number, seed mass, and seed viability and on growth and clonal propagation of non-protected plants in comparison to plants protected from predation by an insecticide. Additionally, we assessed the consequences of seed predation for population growth using matrix projection modelling. Seed predation resulted in a decrease in total seed mass per Flower Head by 23.8% in non-protected plants (P < 0.05). Individual seed mass decreased with increasing infestation intensity (P < 0.05). Seed number remained unaffected because the sucking feeding behaviour by gall midge larvae does not evoke seed abortion. Percent germination of seeds from non-protected plants was reduced by 97.9% compared to seeds from protected plants. According to reduced seed viability, modelling revealed a decrease in population growth rate from λ = 1.055 to λ = 1.041. Predation did neither influence total plant biomass nor biomass fractions. But stolon dry-weight of non-protected plants increased by 24.1% (P < 0.05), which may indicate a trade-off between sexual reproduction and clonal propagation. Our results demonstrate that despite substantial reduction of viable seeds, predation by gall midge larvae only slightly affected population growth of G. reptans suggesting that in this alpine species, persistence by longevity and clonal propagation can balance potential seed losses by predation, at least for local population growth.
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variation of sexual and clonal reproduction in the alpine geum reptans in contrasting altitudes and successional stages
Basic and Applied Ecology, 2005Co-Authors: Tina Weppler, Jurg StocklinAbstract:We studied the relative proportion of sexual vs. clonal reproduction in 20 populations of the alpine pioneer plant Geum reptans in response to altitude (low and high) and succession (early and late). Additionally, the proportion of life-cycle stages, the proportion of reproducing adults, seed size, and seed number per Flower Head were determined. With increasing plant size, the probability of producing both Flower Heads and stolons increased (P > 0.001). Individuals of all size classes tended to produce more Flower Heads than stolons. Stolon production was more frequent only if plants reproduced by one reproductive mode (P > 0.05). The significant difference among populations in sexual reproduction and of seed number per Flower Head was not explained by habitat type. However, clonal reproduction was higher in populations at low and high altitude compared to populations at intermediate altitude (P > 0.05). High altitude populations were characterised by a tendency of small plants to decline and an increase in the proportion of large plants (P > 0.05) whereas the proportion of reproducing adults did not change with altitude. This indicates not only lower recruitment but also, that after successful establishment, growth and reproduction in G. reptans are not generally restricted, even above 2850 m. Our results suggest that variation in the proportion of sexual and clonal reproduction in G. reptans is probably more shaped by individual, i.e. plastic responses to local environmental conditions than by environmental gradients.
Barbara Kołodziej - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the chemical composition of essential oils with respect to the maturity of Flower Heads of Arnica montana L. and Arnica chamissonis Less. cultivated for industry
Industrial Crops and Products, 2015Co-Authors: Radosław Kowalski, Danuta Sugier, Piotr Sugier, Barbara KołodziejAbstract:Abstract The aim of the studies was to evaluate the chemical composition of essential oils extracted from different mature Flower Heads of Arnica montana L. and Arnica chamissonis Less. cultivated for industry. The impact of different stages of Flower development on the quantity and chemical composition of volatile oils of Arnica montana L. and Arnica chamissonis Less. in eastern Poland were studied. The Flower Heads were harvested in four different development phases and the chemical composition of essential oils was investigated by GC/MS. Fifty compounds in the case of A. montana and 62 components in the case of A. chamissonis constitued over 90% of the total oil content. In the case of the two plant species studied, the Flower Head maturity determined the quantity and chemical composition of oils. The content of volatile oils in Flower Heads of A. montana was in the range from 0.158% to 0.195% and in A. chamissonis from 0.137% to 0.194%. The highest content of volatile oils in the Flower Heads of the two plant species studied was noted in the full Flowering phase, when ligulate florets were opened, and up to half of the disc of tubular florets were opened. Differences in the volatile oil content were noted between the species studied only in the stage of yellow buds, whereas in the other stages the contents were similar. E-caryophyllene, alpha-pinene, isopropyl hexadecanoate, farnesyl acetate, alpha-cis-bergamotene, and decanal are the main components that determined the oil chemical differentiation. Generally, higher amounts of E-caryophyllene, farnesyl acetate, and germacrene D were detected in the Flower Heads of A. montana in relation to A. chamissonis . Among the main volatile oil components, isopropyl hexadecanoate and alpha-pinene were present only in the Flower Heads of A. chamissonis , while alpha-cis-bergamotene was only noted in A. montana . The investigations of A. montana volatile oils in the Flower Heads have shown the existence the differences in the chemical profile in relation to other European populations of this species.