The Experts below are selected from a list of 765 Experts worldwide ranked by ideXlab platform
Peter Westhoff - One of the best experts on this subject based on the ideXlab platform.
-
the coordination of major events in c4 photosynthesis evolution in the genus Flaveria
Scientific Reports, 2021Co-Authors: Mingju Amy Lyu, Peter Westhoff, Martha Ludwig, Udo Gowik, Steve Kelly, Sarah Covshoff, Julian M Hibberd, Rowan F Sage, Gane Kashu Wong, Xinguang ZhuAbstract:C4 photosynthesis is a remarkable complex trait, elucidations of the evolutionary trajectory of C4 photosynthesis from its ancestral C3 pathway can help us better understand the generic principles of the evolution of complex traits and guide the engineering of C3 crops for higher yields. Here, we used the genus Flaveria that contains C3, C3-C4, C4-like and C4 species as a system to study the evolution of C4 photosynthesis. We first mapped transcript abundance, protein sequence and morphological features onto the phylogenetic tree of the genus Flaveria, and calculated the evolutionary correlation of different features; we then predicted the relative changes of ancestral nodes of those features to illustrate the major events during the evolution of C4 photosynthesis. We found that gene expression and protein sequence showed consistent modification patterns in the phylogenetic tree. High correlation coefficients ranging from 0.46 to 0.9 among gene expression, protein sequence and morphology were observed. The greatest modification of those different features consistently occurred at the transition between C3-C4 species and C4-like species. Our results show highly coordinated changes in gene expression, protein sequence and morphological features, which support evolutionary major events during the evolution of C4 metabolism.
-
dynamic changes of genome sizes and gradual gain of cell specific distribution of c 4 enzymes during c 4 evolution in genus Flaveria
The Plant Genome, 2021Co-Authors: Yukimi Y Taniguchi, Peter Westhoff, Udo Gowik, Akiho Yokota, Yuto Kinoshita, Risa Kishizaki, Naoaki Ono, Yuri MunekageAbstract:C4 plants are believed to have evolved from C3 plants through various C3 -C4 intermediate stages in which a photorespiration-dependent CO2 concentration system known as C2 photosynthesis operates. Genes involved in the C4 cycle were thought to be recruited from orthologs present in C3 species and developed cell-specific expression during C4 evolution. To understand the process of establishing C4 photosynthesis, we performed whole-genome sequencing and investigated expression and mesophyll- or bundle-sheath-cell-specific localization of phosphoenolpyruvate carboxylase (PEPC), NADP-malic enzyme (NADP-ME), pyruvate, orthophosphate dikinase (PPDK) in C3 , C3 -C4 intermediate, C4 -like, and C4 Flaveria species. While genome sizes vary greatly, the number of predicted protein-coding genes was similar among C3 , C3 -C4 intermediate, C4 -like, and C4 Flaveria species. Cell-specific localization of the PEPC, NADP-ME, and PPDK transcripts was insignificant or weak in C3 -C4 intermediate species, whereas these transcripts were expressed cell-type specific in C4 -like species. These results showed that elevation of gene expression and cell-specific control of pre-existing C4 cycle genes in C3 species was involved in C4 evolution. Gene expression was gradually enhanced during C4 evolution, whereas cell-specific control was gained independently of quantitative transcriptional activation during evolution from C3 -C4 intermediate to C4 photosynthesis in genus Flaveria.
-
transcriptome dynamics in developing leaves from c3 and c4 Flaveria species reveal determinants of kranz anatomy
bioRxiv, 2018Co-Authors: Kumari Billakurthi, Peter Westhoff, Thomas J Wrobel, Andrea Braeutigam, Andreas P M Weber, Udo GowikAbstract:C4 species have evolved more than 60 times independently from C3 ancestors. This multiple and parallel evolution of the complex C4 trait indicates common underlying evolutionary mechanisms that might be identified by comparative analysis of closely related C3 and C4 species. Efficient C4 function depends on a distinctive leaf anatomy that is characterized by enlarged, chloroplast rich bundle sheath cells and a narrow vein spacing. To elucidate molecular mechanisms generating this so called Kranz anatomy, we analyzed a developmental series of leaves from the C4 plant Flaveria bidentis and the closely related C3 species Flaveria robusta using leaf clearing and whole transcriptome sequencing. Applying non-negative matrix factorization on the data identified four different zones with distinct transcriptome patterns in growing leaves of both species. Comparing these transcriptome patterns revealed an important role of auxin metabolism and especially auxin homeostasis for establishing the high vein density typical for C4 leaves.
-
the coordination and jumps along c4 photosynthesis evolution in the genus Flaveria
bioRxiv, 2018Co-Authors: Peter Westhoff, Udo Gowik, Sarah Covshoff, Julian M Hibberd, Amy Lyu M, Y Tao, Steven L Kelly, Harmony Clayton, Rowan F SageAbstract:Abstract Background C4 photosynthesis is a remarkable complex trait, elucidations of the evolutionary trajectory of C4 photosynthesis from its ancestral C3 pathway can help us to better understand the generic principles of complex trait evolution and guide engineering of C3 crops for higher yields. We used the genus Flaveria that contains C3, C3-C4, C4-like and C4 species as a system to study the evolution of C4 photosynthesis. Results We mapped transcript abundance, protein sequence, and morphological features to the phylogenetic tree of the genus Flaveria, and calculated the evolutionary correlation of different features. Besides, we predicted the relative changes of ancestral nodes of those features to illustrate the key stages during the evolution of C4 photosynthesis. Gene expression and protein sequence showed consistent modification pattern along the phylogenetic tree. High correlation coefficients ranging from 0.46 to 0.9 among gene expression, protein sequence and morphology were observed, and the greatest modification of those different features consistently occurred at the transition between C3-C4 species and C4-like species. Conclusions Our data shows highly coordinated changes in gene expression, protein sequence and morphological features. Besides, our results support an obviously evolutionary jump during the evolution of C4 metabolism.
-
a mem1 like motif directs mesophyll cell specific expression of the gene encoding the c4 carbonic anhydrase in Flaveria
Journal of Experimental Botany, 2017Co-Authors: Udo Gowik, Peter Westhoff, Stefanie Schulze, Montserrat Saladie, Vivien Rolland, Sandra K Tanz, Martha LudwigAbstract:The first two reactions of C4 photosynthesis are catalysed by carbonic anhydrase (CA) and phosphoenolpyruvate carboxylase (PEPC) in the leaf mesophyll (M) cell cytosol. Translatome experiments using a tagged ribosomal protein expressed under the control of M and bundle-sheath (BS) cell-specific promoters showed transcripts encoding CA3 from the C4 species Flaveria bidentis were highly enriched in polysomes from M cells relative to those of the BS. Localisation experiments employing a CA3-green fluorescent protein fusion protein showed F. bidentis CA3 is a cytosolic enzyme. A motif showing high sequence homology to that of the Flaveria M expression module 1 (MEM1) element was identified approximately 2 kb upstream of the F. bidentis and F. trinervia ca3 translation start sites. MEM1 is located in the promoter of C4 Flaveria ppcA genes, which encode the C4-associated PEPC, and is necessary for M-specific expression. No MEM1-like sequence was found in the 4 kb upstream of the C3 species F. pringlei ca3 translation start site. Promoter-reporter fusion experiments demonstrated the region containing the ca3 MEM1-like element also directs M-specific expression. These results support the idea that a common regulatory switch drives the expression of the C4 Flaveria ca3 and ppcA1 genes specifically in M cells.
Udo Gowik - One of the best experts on this subject based on the ideXlab platform.
-
the coordination of major events in c4 photosynthesis evolution in the genus Flaveria
Scientific Reports, 2021Co-Authors: Mingju Amy Lyu, Peter Westhoff, Martha Ludwig, Udo Gowik, Steve Kelly, Sarah Covshoff, Julian M Hibberd, Rowan F Sage, Gane Kashu Wong, Xinguang ZhuAbstract:C4 photosynthesis is a remarkable complex trait, elucidations of the evolutionary trajectory of C4 photosynthesis from its ancestral C3 pathway can help us better understand the generic principles of the evolution of complex traits and guide the engineering of C3 crops for higher yields. Here, we used the genus Flaveria that contains C3, C3-C4, C4-like and C4 species as a system to study the evolution of C4 photosynthesis. We first mapped transcript abundance, protein sequence and morphological features onto the phylogenetic tree of the genus Flaveria, and calculated the evolutionary correlation of different features; we then predicted the relative changes of ancestral nodes of those features to illustrate the major events during the evolution of C4 photosynthesis. We found that gene expression and protein sequence showed consistent modification patterns in the phylogenetic tree. High correlation coefficients ranging from 0.46 to 0.9 among gene expression, protein sequence and morphology were observed. The greatest modification of those different features consistently occurred at the transition between C3-C4 species and C4-like species. Our results show highly coordinated changes in gene expression, protein sequence and morphological features, which support evolutionary major events during the evolution of C4 metabolism.
-
dynamic changes of genome sizes and gradual gain of cell specific distribution of c 4 enzymes during c 4 evolution in genus Flaveria
The Plant Genome, 2021Co-Authors: Yukimi Y Taniguchi, Peter Westhoff, Udo Gowik, Akiho Yokota, Yuto Kinoshita, Risa Kishizaki, Naoaki Ono, Yuri MunekageAbstract:C4 plants are believed to have evolved from C3 plants through various C3 -C4 intermediate stages in which a photorespiration-dependent CO2 concentration system known as C2 photosynthesis operates. Genes involved in the C4 cycle were thought to be recruited from orthologs present in C3 species and developed cell-specific expression during C4 evolution. To understand the process of establishing C4 photosynthesis, we performed whole-genome sequencing and investigated expression and mesophyll- or bundle-sheath-cell-specific localization of phosphoenolpyruvate carboxylase (PEPC), NADP-malic enzyme (NADP-ME), pyruvate, orthophosphate dikinase (PPDK) in C3 , C3 -C4 intermediate, C4 -like, and C4 Flaveria species. While genome sizes vary greatly, the number of predicted protein-coding genes was similar among C3 , C3 -C4 intermediate, C4 -like, and C4 Flaveria species. Cell-specific localization of the PEPC, NADP-ME, and PPDK transcripts was insignificant or weak in C3 -C4 intermediate species, whereas these transcripts were expressed cell-type specific in C4 -like species. These results showed that elevation of gene expression and cell-specific control of pre-existing C4 cycle genes in C3 species was involved in C4 evolution. Gene expression was gradually enhanced during C4 evolution, whereas cell-specific control was gained independently of quantitative transcriptional activation during evolution from C3 -C4 intermediate to C4 photosynthesis in genus Flaveria.
-
transcriptome dynamics in developing leaves from c3 and c4 Flaveria species reveal determinants of kranz anatomy
bioRxiv, 2018Co-Authors: Kumari Billakurthi, Peter Westhoff, Thomas J Wrobel, Andrea Braeutigam, Andreas P M Weber, Udo GowikAbstract:C4 species have evolved more than 60 times independently from C3 ancestors. This multiple and parallel evolution of the complex C4 trait indicates common underlying evolutionary mechanisms that might be identified by comparative analysis of closely related C3 and C4 species. Efficient C4 function depends on a distinctive leaf anatomy that is characterized by enlarged, chloroplast rich bundle sheath cells and a narrow vein spacing. To elucidate molecular mechanisms generating this so called Kranz anatomy, we analyzed a developmental series of leaves from the C4 plant Flaveria bidentis and the closely related C3 species Flaveria robusta using leaf clearing and whole transcriptome sequencing. Applying non-negative matrix factorization on the data identified four different zones with distinct transcriptome patterns in growing leaves of both species. Comparing these transcriptome patterns revealed an important role of auxin metabolism and especially auxin homeostasis for establishing the high vein density typical for C4 leaves.
-
the coordination and jumps along c4 photosynthesis evolution in the genus Flaveria
bioRxiv, 2018Co-Authors: Peter Westhoff, Udo Gowik, Sarah Covshoff, Julian M Hibberd, Amy Lyu M, Y Tao, Steven L Kelly, Harmony Clayton, Rowan F SageAbstract:Abstract Background C4 photosynthesis is a remarkable complex trait, elucidations of the evolutionary trajectory of C4 photosynthesis from its ancestral C3 pathway can help us to better understand the generic principles of complex trait evolution and guide engineering of C3 crops for higher yields. We used the genus Flaveria that contains C3, C3-C4, C4-like and C4 species as a system to study the evolution of C4 photosynthesis. Results We mapped transcript abundance, protein sequence, and morphological features to the phylogenetic tree of the genus Flaveria, and calculated the evolutionary correlation of different features. Besides, we predicted the relative changes of ancestral nodes of those features to illustrate the key stages during the evolution of C4 photosynthesis. Gene expression and protein sequence showed consistent modification pattern along the phylogenetic tree. High correlation coefficients ranging from 0.46 to 0.9 among gene expression, protein sequence and morphology were observed, and the greatest modification of those different features consistently occurred at the transition between C3-C4 species and C4-like species. Conclusions Our data shows highly coordinated changes in gene expression, protein sequence and morphological features. Besides, our results support an obviously evolutionary jump during the evolution of C4 metabolism.
-
a mem1 like motif directs mesophyll cell specific expression of the gene encoding the c4 carbonic anhydrase in Flaveria
Journal of Experimental Botany, 2017Co-Authors: Udo Gowik, Peter Westhoff, Stefanie Schulze, Montserrat Saladie, Vivien Rolland, Sandra K Tanz, Martha LudwigAbstract:The first two reactions of C4 photosynthesis are catalysed by carbonic anhydrase (CA) and phosphoenolpyruvate carboxylase (PEPC) in the leaf mesophyll (M) cell cytosol. Translatome experiments using a tagged ribosomal protein expressed under the control of M and bundle-sheath (BS) cell-specific promoters showed transcripts encoding CA3 from the C4 species Flaveria bidentis were highly enriched in polysomes from M cells relative to those of the BS. Localisation experiments employing a CA3-green fluorescent protein fusion protein showed F. bidentis CA3 is a cytosolic enzyme. A motif showing high sequence homology to that of the Flaveria M expression module 1 (MEM1) element was identified approximately 2 kb upstream of the F. bidentis and F. trinervia ca3 translation start sites. MEM1 is located in the promoter of C4 Flaveria ppcA genes, which encode the C4-associated PEPC, and is necessary for M-specific expression. No MEM1-like sequence was found in the 4 kb upstream of the C3 species F. pringlei ca3 translation start site. Promoter-reporter fusion experiments demonstrated the region containing the ca3 MEM1-like element also directs M-specific expression. These results support the idea that a common regulatory switch drives the expression of the C4 Flaveria ca3 and ppcA1 genes specifically in M cells.
Rowan F Sage - One of the best experts on this subject based on the ideXlab platform.
-
the coordination of major events in c4 photosynthesis evolution in the genus Flaveria
Scientific Reports, 2021Co-Authors: Mingju Amy Lyu, Peter Westhoff, Martha Ludwig, Udo Gowik, Steve Kelly, Sarah Covshoff, Julian M Hibberd, Rowan F Sage, Gane Kashu Wong, Xinguang ZhuAbstract:C4 photosynthesis is a remarkable complex trait, elucidations of the evolutionary trajectory of C4 photosynthesis from its ancestral C3 pathway can help us better understand the generic principles of the evolution of complex traits and guide the engineering of C3 crops for higher yields. Here, we used the genus Flaveria that contains C3, C3-C4, C4-like and C4 species as a system to study the evolution of C4 photosynthesis. We first mapped transcript abundance, protein sequence and morphological features onto the phylogenetic tree of the genus Flaveria, and calculated the evolutionary correlation of different features; we then predicted the relative changes of ancestral nodes of those features to illustrate the major events during the evolution of C4 photosynthesis. We found that gene expression and protein sequence showed consistent modification patterns in the phylogenetic tree. High correlation coefficients ranging from 0.46 to 0.9 among gene expression, protein sequence and morphology were observed. The greatest modification of those different features consistently occurred at the transition between C3-C4 species and C4-like species. Our results show highly coordinated changes in gene expression, protein sequence and morphological features, which support evolutionary major events during the evolution of C4 metabolism.
-
the coordination and jumps along c4 photosynthesis evolution in the genus Flaveria
bioRxiv, 2018Co-Authors: Peter Westhoff, Udo Gowik, Sarah Covshoff, Julian M Hibberd, Amy Lyu M, Y Tao, Steven L Kelly, Harmony Clayton, Rowan F SageAbstract:Abstract Background C4 photosynthesis is a remarkable complex trait, elucidations of the evolutionary trajectory of C4 photosynthesis from its ancestral C3 pathway can help us to better understand the generic principles of complex trait evolution and guide engineering of C3 crops for higher yields. We used the genus Flaveria that contains C3, C3-C4, C4-like and C4 species as a system to study the evolution of C4 photosynthesis. Results We mapped transcript abundance, protein sequence, and morphological features to the phylogenetic tree of the genus Flaveria, and calculated the evolutionary correlation of different features. Besides, we predicted the relative changes of ancestral nodes of those features to illustrate the key stages during the evolution of C4 photosynthesis. Gene expression and protein sequence showed consistent modification pattern along the phylogenetic tree. High correlation coefficients ranging from 0.46 to 0.9 among gene expression, protein sequence and morphology were observed, and the greatest modification of those different features consistently occurred at the transition between C3-C4 species and C4-like species. Conclusions Our data shows highly coordinated changes in gene expression, protein sequence and morphological features. Besides, our results support an obviously evolutionary jump during the evolution of C4 metabolism.
-
mesophyll chloroplast investment in c3 c4 and c2 species of the genus Flaveria
Plant and Cell Physiology, 2016Co-Authors: Matt Stata, Sarah Covshoff, Tammy L Sage, Natalie Hoffmann, Gane Kashu Wong, Rowan F SageAbstract:The mesophyll (M) cells of C4 plants contain fewer chloroplasts than observed in related C3 plants; however, it is uncertain where along the evolutionary transition from C3 to C4 that the reduction in M chloroplast number occurs. Using 18 species in the genus Flaveria, which contains C3, C4 and a range of C3-C4 intermediate species, we examined changes in chloroplast number and size per M cell, and positioning of chloroplasts relative to the M cell periphery. Chloroplast number and coverage of the M cell periphery declined in proportion to increasing strength of C4 metabolism in Flaveria, while chloroplast size increased with increasing C4 cycle strength. These changes increase cytosolic exposure to the cell periphery which could enhance diffusion of inorganic carbon to phosphenolpyruvate carboxylase (PEPC), a cytosolic enzyme. Analysis of the transcriptome from juvenile leaves of nine Flaveria species showed that the transcript abundance of four genes involved in plastid biogenesis-FtsZ1, FtsZ2, DRP5B and PARC6-was negatively correlated with variation in C4 cycle strength and positively correlated with M chloroplast number per planar cell area. Chloroplast size was negatively correlated with abundance of FtsZ1, FtsZ2 and PARC6 transcripts. These results indicate that natural selection targeted the proteins of the contractile ring assembly to effect the reduction in chloroplast numbers in the M cells of C4 Flaveria species. If so, efforts to engineer the C4 pathway into C3 plants might evaluate whether inducing transcriptome changes similar to those observed in Flaveria could reduce M chloroplast numbers, and thus introduce a trait that appears essential for efficient C4 function.
-
rna seq based phylogeny recapitulates previous phylogeny of the genus Flaveria asteraceae with some modifications
BMC Evolutionary Biology, 2015Co-Authors: Mingju Amy Lyu, Peter Westhoff, Udo Gowik, Steve Kelly, Sarah Covshoff, Julia Mallmann, Julian M Hibberd, Matt Stata, Rowan F Sage, Xiaofeng WeiAbstract:The genus Flaveria has been extensively used as a model to study the evolution of C4 photosynthesis as it contains C3 and C4 species as well as a number of species that exhibit intermediate types of photosynthesis. The current phylogenetic tree of the genus Flaveria contains 21 of the 23 known Flaveria species and has been previously constructed using a combination of morphological data and three non-coding DNA sequences (nuclear encoded ETS, ITS and chloroplast encoded trnL-F). Here we developed a new strategy to update the phylogenetic tree of 16 Flaveria species based on RNA-Seq data. The updated phylogeny is largely congruent with the previously published tree but with some modifications. We propose that the data collection method provided in this study can be used as a generic method for phylogenetic tree reconstruction if the target species has no genomic information. We also showed that a “F. pringlei” genotype recently used in a number of labs may be a hybrid between F. pringlei (C3) and F. angustifolia (C3-C4). We propose that the new strategy of obtaining phylogenetic sequences outlined in this study can be used to construct robust trees in a larger number of taxa. The updated Flaveria phylogenetic tree also supports a hypothesis of stepwise and parallel evolution of C4 photosynthesis in the Flavaria clade.
-
initial events during the evolution of c4 photosynthesis in c3 species of Flaveria
Plant Physiology, 2013Co-Authors: Tammy L Sage, Stephen Rawsthorne, Matt Stata, Florian A Busch, Daniel C Johnson, Patrick C Friesen, Corey R Stinson, Stefanie Sultmanis, Beshar Rahman, Rowan F SageAbstract:The evolution of C4 photosynthesis in many taxa involves the establishment of a two-celled photorespiratory CO2 pump, termed C2 photosynthesis. How C3 species evolved C2 metabolism is critical to understanding the initial phases of C4 plant evolution. To evaluate early events in C4 evolution, we compared leaf anatomy, ultrastructure, and gas-exchange responses of closely related C3 and C2 species of Flaveria, a model genus for C4 evolution. We hypothesized that Flaveria pringlei and Flaveria robusta, two C3 species that are most closely related to the C2 Flaveria species, would show rudimentary characteristics of C2 physiology. Compared with less-related C3 species, bundle sheath (BS) cells of F. pringlei and F. robusta had more mitochondria and chloroplasts, larger mitochondria, and proportionally more of these organelles located along the inner cell periphery. These patterns were similar, although generally less in magnitude, than those observed in the C2 species Flaveria angustifolia and Flaveria sonorensis. In F. pringlei and F. robusta, the CO2 compensation point of photosynthesis was slightly lower than in the less-related C3 species, indicating an increase in photosynthetic efficiency. This could occur because of enhanced refixation of photorespired CO2 by the centripetally positioned organelles in the BS cells. If the phylogenetic positions of F. pringlei and F. robusta reflect ancestral states, these results support a hypothesis that increased numbers of centripetally located organelles initiated a metabolic scavenging of photorespired CO2 within the BS. This could have facilitated the formation of a glycine shuttle between mesophyll and BS cells that characterizes C2 photosynthesis.
Yun Wei - One of the best experts on this subject based on the ideXlab platform.
-
determination of major components and fingerprint analysis of Flaveria bidentis l kuntze
Journal of Chromatographic Science, 2014Co-Authors: Qianqian Xie, Yun Wei, Liping Ding, Yoichiro ItoAbstract:A sensitive high-performance liquid chromatography method coupled with photodiode array detection was developed for the simultaneous determination of six major constituents in Flaveria bidentis (L.) Kuntze: hyperoside, patuletin-3-O-glucoside, isorhamnetin 3-sulfate, astragalin, 6-methoxykaempferol-3-O-galactoside and α-terthienyl. The chemical fingerprint of Flaveria bidentis (L.) Kuntze leaves was established using raw materials of 12 batches in China. The chromatographic separations were obtained by using an Eclipse XDB-C18 reserved-phase column (150 × 4.6 mm i.d., 5 µm) using gradient elution with water (0.0125% trifluoroacetic acid, v/v) and acetonitrile at a flow rate of 1.0 mL/min, an operating temperature of 30°C and a detection wavelength of 360 nm. The new method was validated by linearity, limits of detection and quantification, precision, reproducibility, stability and recovery, and was also successfully applied to the simultaneous determination of components in Flaveria bidentis (L.) Kuntze. The results indicate that this multi-component determination method in combination with chromatographic fingerprint analysis is suitable for the quantitative analysis and identification of Flaveria bidentis (L.) Kuntze.
-
preparative separation of bioactive compounds from essential oil of Flaveria bidentis l kuntze using steam distillation extraction and one step high speed counter current chromatography
IEEE Journal of Solid-state Circuits, 2012Co-Authors: Yun WeiAbstract:In order to utilize and control the invasive weed, bioactive compounds from essential oil of Flaveria bidentis (L.) Kuntze were studied. Steam distillation extraction and one step high-speed counter-current chromatography were applied to separate and purify the caryophyllene oxide, 7,11-dimethyl-3-methylene-1,6,10-dodecatriene, and caryophyllene from essential oil of Flaveria bidentis (L.) Kuntze. The two-phase solvent system containing n-hexane/acetonitrile/ethanol (5:4:3, v/v/v) was selected for the one step separation mode according to the partition coefficient values (K) of the target compounds and the separation factor (α). The purity of each isolated fraction after a single high-speed counter-current chromatography run was determined by high performance liquid chromatography. A 3.2 mg of caryophyllene oxide at a purity of 92.6%, 10.4 mg of 7,11-dimethyl-3-methylene-1,6,10-dodecatriene at a purity of 99.1% and 5.7 mg of caryophyllene at a purity of 98.8% were obtained from 200 mg essential oil of Flaveria bidentis (L.) Kuntze. The chemical structures of these components were identified by GC-MS, (1) H-NMR, and (13) C-NMR.
-
isolation of bioactive components from Flaveria bidentis l kuntze using high speed counter current chromatography and time controlled collection method
Journal of Separation Science, 2012Co-Authors: Yun Wei, Kai Zhang, Li Yin, Guoliang ZhangAbstract:Semipreparative high-speed counter-current chromatography (HSCCC) by time-controlled collection method was successfully applied for isolation and purification of α-terthienyl, 5-(3-buten-1-ynyl)-2,2'-bithienyl, and 5-(3-penten-1-ynyl)-2,2'-bithienyl from Flaveria bidentis (L.) Kuntze for the first time. The two-phase solvent system composed of n-hexane and acetonitrile at the volume ratio of 1:1 (v/v) was used for the semipreparative HSCCC. The 5.2 mg α-terthienyl, 2.2 mg 5-(3-buten-1-ynyl)-2,2'-bithienyl, and 4.3 mg 5-(3-penten-1-ynyl)-2,2'-bithienyl with the purity of 99.9, 90.2, and 92.1% were produced from 265.6 mg crude extract, respectively, and 5-(3-penten-1-ynyl)-2,2'-bithienyl was first isolated from Flaveria bidentis (L.) Kuntze. The structures of the separated compounds were identified by electrospray-ionization mass spectrometry and proton and carbon nuclear magnetic resonance ((1)H- and (13)C-NMR).
-
separation and purification of isorhamnetin 3 sulphate from Flaveria bidentis l kuntze by counter current chromatography comparing two kinds of solvent systems
Journal of Separation Science, 2012Co-Authors: Qianqian Xie, Li Yin, Guoliang Zhang, Yun WeiAbstract:The first preparative separation of a flavonoid sulphate isorhamnetin 3-sulphate from Flaveria bidentis (L.) Kuntze by counter-current chromatography (CCC) was presented. Two kinds of solvent systems were used. A conventional organic/aqueous solvent system n-butanol–ethyl acetate–water (4:1:5, v/v) was used, yielding isorhamnetin 3-sulphate 2.0 mg with a purity of 93.4% from 83 mg of pre-enriched crude extract obtained from 553 mg ethanol extract by macroporous resin. A one-component organic/salt-containing system composed of n-butanol–0.25% sodium chloride aqueous solution (1:1, v/v) was also used, and the LC column packed with macroporous resin has been employed for desalination of the target compound purified from CCC. As a result, 2.1 mg of isorhamnetin 3-sulphate with a purity of over 97% has been isolated from 402 mg of crude extract without pre-enrichment. Compared with the conventional organic/aqueous system, the one-component organic/salt-containing aqueous system was more suitable for the separation of isorhamnetin 3-sulphate, and purer target compound was obtained from the crude extract without pre-enrichment using the new solvent system. The chemical structure was confirmed by ESI-MS and 1H, 13C NMR. In summary, our results indicated that CCC using one-component organic/salt-containing aqueous solution is very promising and powerful for high-throughput purification of isorhamnetin 3-sulphate from Flaveria bidentis (L.) Kuntze.
Jeroni Galmes - One of the best experts on this subject based on the ideXlab platform.
-
Temperature dependence of in vitro Rubisco kinetics in species of Flaveria with different photosynthetic mechanisms
Photosynthesis Research, 2015Co-Authors: Juan Alejandro Perdomo, David S. Kubien, Amanda P. Cavanagh, Jeroni GalmesAbstract:There is general consensus in the literature that plants with different photosynthetic mechanisms (i.e. C_3 vs. C_4) have Rubiscos characterised by different kinetic performances. However, potential differences in the temperature dependencies of Rubisco kinetic parameters between C_3 and C_4 plants are uncertain. Accordingly, six species of Flaveria with contrasting photosynthetic mechanisms (C_3, C_3/C_4 and C_4) were selected and their Rubisco Michaelis–Menten constants for CO_2 and RuBP ( K _c and K _RuBP), carboxylase catalytic turnover rate ( $${k_{\text{cat}}}^{\text{c}}$$ k cat c ) and CO_2/O_2 specificity factor ( S _c/o) were measured between 10 and 40 °C. The results confirmed different Rubisco characteristics between C_3 and C_4 plants. Rubisco from the C_3 species had higher E _a for K _c and $${k_{\text{cat}}}^{\text{c}}$$ k cat c than that from C_4 species, which were translated into differences in the temperature response of the carboxylase catalytic efficiency ( $${k_{\text{cat}}}^{\text{c}}$$ k cat c / K _c). However, E _a did not differ for S _c/o or K _RuBP. Although a mechanism remains uncertain, it appears that the Asp/Glu-149-Ala and Met-309-Ile substitutions lead to differences in the temperature responses of catalysis between C_3 and C_4 Rubiscos in Flaveria . Therefore, the above observations are consistent with the fact that C_3 species have a higher photosynthetic efficiency and ecological dominance in cool environments, with respect to C_4 species in temperate environments.
-
isoleucine 309 acts as a c4 catalytic switch that increases ribulose 1 5 bisphosphate carboxylase oxygenase rubisco carboxylation rate in Flaveria
Proceedings of the National Academy of Sciences of the United States of America, 2011Co-Authors: Spencer M. Whitney, Robert E Sharwood, Douglas J Orr, Sarah White, Hernan Alonso, Jeroni GalmesAbstract:Improving global yields of important agricultural crops is a complex challenge. Enhancing yield and resource use by engineering improvements to photosynthetic carbon assimilation is one potential solution. During the last 40 million years C4 photosynthesis has evolved multiple times, enabling plants to evade the catalytic inadequacies of the CO2-fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). Compared with their C3 ancestors, C4 plants combine a faster rubisco with a biochemical CO2-concentrating mechanism, enabling more efficient use of water and nitrogen and enhanced yield. Here we show the versatility of plastome manipulation in tobacco for identifying sequences in C4-rubisco that can be transplanted into C3-rubisco to improve carboxylation rate (VC). Using transplastomic tobacco lines expressing native and mutated rubisco large subunits (L-subunits) from Flaveria pringlei (C3), Flaveria floridana (C3-C4), and Flaveria bidentis (C4), we reveal that Met-309-Ile substitutions in the L-subunit act as a catalytic switch between C4 (309Ile; faster VC, lower CO2 affinity) and C3 (309Met; slower VC, higher CO2 affinity) catalysis. Application of this transplastomic system permits further identification of other structural solutions selected by nature that can increase rubisco VC in C3 crops. Coengineering a catalytically faster C3 rubisco and a CO2-concentrating mechanism within C3 crop species could enhance their efficiency in resource use and yield.