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Hunter E, Stander M, Kossmann J, Chakraborty S, Prince S, Peters S, Loedolff B. Toward the identification of a phytocannabinoid-like compound in the flowers of a South African medicinal plant (Leonotis leonurus). BMC Res Notes 2020; 13:522. [PMID: 33172494 PMCID: PMC7653773 DOI: 10.1186/s13104-020-05372-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 10/31/2020] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE Current global trends on natural therapeutics suggest an increasing market interest toward the use and discovery of new plant-derived therapeutic compounds, often referred to as traditional medicine (TM). The Cannabis industry is currently one such focal area receiving attention, owing to the occurrence of phytocannabinoids (pCBs) which have shown promise in health-promotion and disease prevention. However, the occurrence of pCBs in other plant species are often overlooked and rarely studied. Leonotis leonurus (L.) R. Br. is endemic to South Africa with a rich history of use in TM practices amongst indigenous people and, has been recorded to induce mild psychoactive effects akin to Cannabis. While the leaves have been well-reported to contain therapeutic phytochemicals, little information exists on the flowers. Consequently, as part of a larger research venture, we targeted the flowers of L. leonurus for the identification of potential pCB or pCB-like compounds. RESULTS Flower extracts were separated and analyzed using high performance thin layer chromatography (HPTLC). A single pCB candidate was isolated from HPTLC plates and, using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), we could successfully group this compound as a fatty amide and tentatively identified as 7,10,13,16-Docosatetraenoylethanolamine (adrenoyl-EA), a known bioactive compound.
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Affiliation(s)
- E. Hunter
- Department of Genetics, Institute of Plant Biotechnology, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa
| | - M. Stander
- Central Analytical Facilities, Stellenbosch University, Stellenbosch, South Africa
| | - J. Kossmann
- Department of Genetics, Institute of Plant Biotechnology, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa
| | - S. Chakraborty
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - S. Prince
- Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - S. Peters
- Department of Genetics, Institute of Plant Biotechnology, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa
| | - Bianke Loedolff
- Department of Genetics, Institute of Plant Biotechnology, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa
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Bauer R, Hiten F, Crouch A, Kossmann J, Burger B. Acrolein Dimer as a Marker for Direct Detection of Acrolein in Wine. ACTA ACUST UNITED AC 2016. [DOI: 10.21548/33-1-1308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Basson CE, Groenewald JH, Kossmann J, Cronjé C, Bauer R. Upregulation of pyrophosphate: fructose 6-phosphate 1-phosphotransferase (PFP) activity in strawberry. Transgenic Res 2010; 20:925-31. [PMID: 20960058 DOI: 10.1007/s11248-010-9451-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 10/02/2010] [Indexed: 11/26/2022]
Abstract
Pyrophosphate: fructose 6-phosphate 1-phosphotransferase (PFP) is a cytosolic enzyme catalyzing the first committed step in glycolysis by reversibly phosphorylating fructose-6-phosphate to fructose-1,6-bisphosphate. The position of PFP in glycolytic and gluconeogenic metabolism, as well as activity patterns in ripening strawberry, suggest that the enzyme may influence carbohydrate allocation to sugars and organic acids. Fructose-2,6-bisphosphate activates and tightly regulates PFP activity in plants and has hampered attempts to increase PFP activity through overexpression. Heterologous expression of a homodimeric isoform from Giardia lamblia, not regulated by fructose-2,6-bisphosphate, was therefore employed to ensure in vivo increases in PFP activity. The coding sequence was placed into a constitutive expression cassette under control of the cauliflower mosaic virus 35S promoter and introduced into strawberry by Agrobacterium tumefaciens-mediated transformation. Heterologous expression of PFP resulted in an up to eightfold increase in total activity in ripe berries collected over two consecutive growing seasons. Total sugar and organic acid content of transgenic berries harvested during the first season were not affected when compared to the wild type, however, fructose content increased at the expense of sucrose. In the second season, total sugar content and composition remained unchanged while the citrate content increased slightly. Considering that PFP catalyses a reversible reaction, PFP activity appears to shift between gluconeogenic and glycolytic metabolism, depending on the metabolic status of the cell.
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Affiliation(s)
- C E Basson
- Institute for Plant Biotechnology, Genetics Department, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch, 7602, South Africa
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Basson C, Groenewald JH, Kossmann J, Cronjé C, Bauer R. Sugar and acid-related quality attributes and enzyme activities in strawberry fruits: Invertase is the main sucrose hydrolysing enzyme. Food Chem 2010. [DOI: 10.1016/j.foodchem.2010.01.064] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Zimmermann P, Regierer B, Kossmann J, Frossard E, Amrhein N, Bucher M. Differential expression of three purple acid phosphatases from potato. Plant Biol (Stuttg) 2004; 6:519-28. [PMID: 15375722 DOI: 10.1055/s-2004-821091] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Three cDNAs encoding purple acid phosphatase (PAP) were cloned from potato (Solanum tuberosum L. cv. Désirée) and expression of the corresponding genes was characterised. StPAP1 encodes a low-molecular weight PAP clustering with mammalian, cyanobacterial, and other plant PAPs. It was highly expressed in stem and root and its expression did not change in response to phosphorus (P) deprivation. StPAP2 and StPAP3 code for high-molecular weight PAPs typical for plants. Corresponding gene expression was shown to be responsive to the level of P supply, with transcripts of StPAP2 and StPAP3 being most abundant in P-deprived roots or both stem and roots, respectively. Root colonisation by arbuscular mycorrhizal fungi had no effect on the expression of any of the three PAP genes. StPAP1 mRNA is easily detectable along the root axis, including root hairs, but is barely detectable in root tips. In contrast, both StPAP2 and StPAP3 transcripts are abundant along the root axis, but absent in root hairs, and are most abundant in the root tip. All three PAPs described contain a predicted N-terminal secretion signal and could play a role in extracellular P scavenging, P mobilisation from the rhizosphere, or cell wall regeneration.
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MESH Headings
- Acid Phosphatase/genetics
- Amino Acid Sequence
- Base Sequence
- DNA, Complementary/genetics
- DNA, Plant/genetics
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant
- Glycoproteins/genetics
- Isoenzymes/genetics
- Molecular Sequence Data
- Mycorrhizae/physiology
- Phosphoric Monoester Hydrolases/metabolism
- Phosphorus/metabolism
- Phylogeny
- Plant Roots/enzymology
- Protein Sorting Signals/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Sequence Homology, Amino Acid
- Solanum tuberosum/enzymology
- Solanum tuberosum/genetics
- Solanum tuberosum/microbiology
- Symbiosis
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Affiliation(s)
- P Zimmermann
- Swiss Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Experimental Station Eschikon, 8315 Lindau, Switzerland
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Yu TS, Kofler H, Häusler RE, Hille D, Flügge UI, Zeeman SC, Smith AM, Kossmann J, Lloyd J, Ritte G, Steup M, Lue WL, Chen J, Weber A. The Arabidopsis sex1 mutant is defective in the R1 protein, a general regulator of starch degradation in plants, and not in the chloroplast hexose transporter. Plant Cell 2001. [PMID: 11487701 DOI: 10.2307/3871327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Starch is the major storage carbohydrate in higher plants and of considerable importance for the human diet and for numerous technical applications. In addition, starch can be accumulated transiently in chloroplasts as a temporary deposit of carbohydrates during ongoing photosynthesis. This transitory starch has to be mobilized during the subsequent dark period. Mutants defective in starch mobilization are characterized by high starch contents in leaves after prolonged periods of darkness and therefore are termed starch excess (sex) mutants. Here we describe the molecular characterization of the Arabidopsis sex1 mutant that has been proposed to be defective in the export of glucose resulting from hydrolytic starch breakdown. The mutated gene in sex1 was cloned using a map-based cloning approach. By complementation of the mutant, immunological analysis, and analysis of starch phosphorylation, we show that sex1 is defective in the Arabidopsis homolog of the R1 protein and not in the hexose transporter. We propose that the SEX1 protein (R1) functions as an overall regulator of starch mobilization by controlling the phosphate content of starch.
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Affiliation(s)
- T S Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
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Yu TS, Kofler H, Häusler RE, Hille D, Flügge UI, Zeeman SC, Smith AM, Kossmann J, Lloyd J, Ritte G, Steup M, Lue WL, Chen J, Weber A. The Arabidopsis sex1 mutant is defective in the R1 protein, a general regulator of starch degradation in plants, and not in the chloroplast hexose transporter. Plant Cell 2001. [PMID: 11487701 DOI: 10.1105/tpc.13.8.1907] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Starch is the major storage carbohydrate in higher plants and of considerable importance for the human diet and for numerous technical applications. In addition, starch can be accumulated transiently in chloroplasts as a temporary deposit of carbohydrates during ongoing photosynthesis. This transitory starch has to be mobilized during the subsequent dark period. Mutants defective in starch mobilization are characterized by high starch contents in leaves after prolonged periods of darkness and therefore are termed starch excess (sex) mutants. Here we describe the molecular characterization of the Arabidopsis sex1 mutant that has been proposed to be defective in the export of glucose resulting from hydrolytic starch breakdown. The mutated gene in sex1 was cloned using a map-based cloning approach. By complementation of the mutant, immunological analysis, and analysis of starch phosphorylation, we show that sex1 is defective in the Arabidopsis homolog of the R1 protein and not in the hexose transporter. We propose that the SEX1 protein (R1) functions as an overall regulator of starch mobilization by controlling the phosphate content of starch.
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Affiliation(s)
- T S Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
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Yu TS, Kofler H, Häusler RE, Hille D, Flügge UI, Zeeman SC, Smith AM, Kossmann J, Lloyd J, Ritte G, Steup M, Lue WL, Chen J, Weber A. The Arabidopsis sex1 mutant is defective in the R1 protein, a general regulator of starch degradation in plants, and not in the chloroplast hexose transporter. Plant Cell 2001; 13:1907-18. [PMID: 11487701 PMCID: PMC139133 DOI: 10.1105/tpc.010091] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2001] [Accepted: 05/28/2001] [Indexed: 05/17/2023]
Abstract
Starch is the major storage carbohydrate in higher plants and of considerable importance for the human diet and for numerous technical applications. In addition, starch can be accumulated transiently in chloroplasts as a temporary deposit of carbohydrates during ongoing photosynthesis. This transitory starch has to be mobilized during the subsequent dark period. Mutants defective in starch mobilization are characterized by high starch contents in leaves after prolonged periods of darkness and therefore are termed starch excess (sex) mutants. Here we describe the molecular characterization of the Arabidopsis sex1 mutant that has been proposed to be defective in the export of glucose resulting from hydrolytic starch breakdown. The mutated gene in sex1 was cloned using a map-based cloning approach. By complementation of the mutant, immunological analysis, and analysis of starch phosphorylation, we show that sex1 is defective in the Arabidopsis homolog of the R1 protein and not in the hexose transporter. We propose that the SEX1 protein (R1) functions as an overall regulator of starch mobilization by controlling the phosphate content of starch.
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Affiliation(s)
- T S Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
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Altmann T, Kossmann J. Photosynthesis and primary metabolism. Trends Plant Sci 2001; 6:93-94. [PMID: 11327048 DOI: 10.1016/s1360-1385(00)01859-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- T Altmann
- Max-Planck-Institute fur Molekulare Pflanzephysiologie, 1447 Golm, Germany. e-mail:
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Kossmann J, Nestel P, Herrera MG, El-Amin A, Fawzi WW. Undernutrition and childhood infections: a prospective study of childhood infections in relation to growth in the Sudan. Acta Paediatr 2000; 89:1122-8. [PMID: 11071096 DOI: 10.1080/713794561] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
UNLABELLED The relationships between both diarrhoea and respiratory infections and linear and ponderal growth were prospectively examined among 28 753 Sudanese pre-school children. Childhood infections were significantly and inversely associated with attained height and attained weight and gain in height and weight over a 6-mo period. They were significantly and positively associated also with stunting after adjusting for age, gender, socio-economic status, dietary variables and previous morbidity. Attained height was on average 17 mm lower (95% CI [-19 -15]) for children with diarrhoea and 11 mm lower (95% CI [-3 -9]) for children with complicated cough than for those without these symptoms. The association between morbidity and attained weight was significant for diarrhoea and complicated cough, but the differences between children with and without symptoms were negligible. The risk of being stunted 6 mo later was 1.38 times (95% CI [1.20 1.59]), 1.29 times (95% CI [0.97 1.72]) and 1.32 times (95% CI [1.13 1.54]) greater among normally-nourished children with diarrhoea, febrile diarrhoea and fever, respectively, than among children without these symptoms. The difference in attained height between children with diarrhoea or complicated cough and those without symptoms increased with age, and was larger among the non-breastfed children compared with breastfed children. CONCLUSION The results underline the need to reduce child morbidity to prevent the impairment of growth and development.
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Affiliation(s)
- J Kossmann
- Department of Epidemiology and Nutrition, Harvard School of Public Health, Boston, MA 02115, USA
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Tauberger E, Fernie AR, Emmermann M, Renz A, Kossmann J, Willmitzer L, Trethewey RN. Antisense inhibition of plastidial phosphoglucomutase provides compelling evidence that potato tuber amyloplasts import carbon from the cytosol in the form of glucose-6-phosphate. Plant J 2000; 23:43-53. [PMID: 10929100 DOI: 10.1046/j.1365-313x.2000.00783.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The aim of this work was to establish whether plastidial phosphoglucomutase is involved in the starch biosynthetic pathway of potato tubers and thereby to determine the form in which carbon is imported into the potato amyloplast. For this purpose, we cloned the plastidial isoform of potato PGM (StpPGM), and using an antisense approach generated transgenic potato plants that exhibited decreased expression of the StpPGM gene and contained significantly reduced total phosphoglucomutase activity. We confirmed that this loss in activity was due specifically to a reduction in plastidial PGM activity. Potato lines with decreased activities of plastidial PGM exhibited no major changes in either whole-plant or tuber morphology. However, tubers from these lines exhibited a dramatic (up to 40%) decrease in the accumulation of starch, and significant increases in the levels of sucrose and hexose phosphates. As tubers from these lines exhibited no changes in the maximal catalytic activities of other key enzymes of carbohydrate metabolism, we conclude that plastidial PGM forms part of the starch biosynthetic pathway of the potato tuber, and that glucose-6-phosphate is the major precursor taken up by amyloplasts in order to support starch synthesis.
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Affiliation(s)
- E Tauberger
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Golm, Germany
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Abstract
OBJECTIVE The aim of the study was to examine the relationships between nutritional status and diarrhoea and respiratory infections. DESIGN Prospective cohort study within the framework of a randomized double-blind placebo-controlled intervention trial. SETTING In rural communities in the Khartoum and Gezira regions, in Northern Sudan. SUBJECTS 28,753 Sudanese pre-school children between 6 months and 6 y old. METHODS Relative risks of subsequent diarrhoea and respiratory infections in relation to nutritional status measured by anthropometry (Z-scores of height-for-age (H/A), weight-for-height (W/H), and weight-for-age (W/A), which reflect stunting, wasting and underweight, respectively) were estimated using odds ratios from logistic regression adjusting for various covariates. RESULTS H/A, W/H and W/A were significantly and inversely associated with subsequent diarrhoea and febrile diarrhoea (P for trend <0.001) with risks being 2.00 times higher (95% confidence interval, CI (1.64, 2.43)) among children with W/A Z-scores below -4 Z, and 1.75 times higher (95% CI (1.56, 1.96)) among those with a W/A Z-score between -4 and -3 Z compared with children having a W/A Z-score > or =1. Age, gender, region of residence and seasonality modified these associations. Also, febrile cough was inversely associated with W/A and W/H (P<0.03), with risks ranging from 1.41 times higher (95% CI (1.02, 1.97)) to 1.21 times higher (95% CI (1.04, 1.41)) in the group of underweight children with W/A Z-scores below -4 and between -2 and -1 Z, all compared with normally nourished children (> or =-1 Z). CONCLUSIONS The reduction of severe but also mild and moderate undernutrition is necessary through nutrition, health and socio-economic improvement in order to prevent morbidity.
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Affiliation(s)
- J Kossmann
- Harvard Institute for International Development, Cambridge, MA, USA
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van Voorthuysen T, Regierer B, Springer F, Dijkema C, Vreugdenhil D, Kossmann J. Introduction of polyphosphate as a novel phosphate pool in the chloroplast of transgenic potato plants modifies carbohydrate partitioning. J Biotechnol 2000; 77:65-80. [PMID: 10674215 DOI: 10.1016/s0168-1656(99)00208-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Potato plants (Solanum tuberosum L., cv. Désirée) were transformed with the polyphosphate kinase gene from Escherichia coli fused to the leader sequence of the ferredoxin oxidoreductase gene (FNR) from Spinacea oleracea under the control of the leaf specific St-LS1 promoter to introduce a novel phosphate pool in the chloroplasts of green tissues. Transgenic plants (cpPPK) in tissue culture developed necrotic lesions in older leaves and showed earlier leaf senescence while greenhouse plants showed no noticeable phenotype. Leaves of cpPPK plants contained less starch but higher concentrations of soluble sugars. The presence of polyphosphate in cpPPK leaves was demonstrated by toluidine blue staining and unambiguously verified and quantified by in vitro 31P-NMR of extracts. Polyphosphate accumulated during leaf development from 0.06 in juvenile leaves to 0.83 mg P g-1 DW in old leaves and had an average chain length of 18 residues in mature leaves. In situ 31P-NMR on small leaf pieces perfused with well-oxygenated medium showed only 0.036 mg P g-1 DW polyphosphate that was, however, greatly increased upon treatment with 50 mM ammonium sulfate at pH 7.3. This phenomenon along with a yield of 0.47 mg P g-1 DW polyphosphate from an extract of the same leaf material suggests that 93% of the polyphosphate pool is immobile. This conclusion is substantiated by the observation that no differences in polyphosphate pool sizes could be discerned between darkened and illuminated leaves, leaves treated with methylviologen or anaerobis and control leaves, treatments causing a change in the pool of ATP available for polyPi synthesis. Results are discussed in the context of the chelating properties of polyphosphates for cations and its consequences for the partitioning of photoassimilate between starch and soluble sugars.
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Affiliation(s)
- T van Voorthuysen
- Department of Plant Sciences, Wageningen University, The Netherlands
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Abstract
Starch is one of the most important products synthesized by plants that is used in industrial processes. If it were possible to increase production or modify starches in vivo, using combinations or either genetically altered or mutant plants, it may make them cheaper for use by industry, or open up new markets for the modified starches. The conversion of sucrose to starch in storage organs is, therefore, discussed. In particular the roles of the different enzymes directly involved in synthesizing the starch molecules on altering starch structure are reviewed, as well as the different models for the production of the fine structure of amylopectin. In addition, the process of starch phosphorylation, which is also important in determining the physical properties of starches, is reviewed. It is hoped that detailed knowledge of these processes will lead to the rational design of tailored starches. Starch degradation is also an important process, for example, in the cold-sweetening of potato tubers, but outside of cereal endosperm little is known about the processes involved. The enzymes thought to be involved and the evidence for this are discussed.
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Affiliation(s)
- J Kossmann
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam, Germany.
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Lloyd JR, Springer F, Buléon A, Müller-Röber B, Willmitzer L, Kossmann J. The influence of alterations in ADP-glucose pyrophosphorylase activities on starch structure and composition in potato tubers. Planta 1999; 209:230-238. [PMID: 10436226 DOI: 10.1007/s004250050627] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In order to examine whether alterations in the supply of precursor molecules into the starch biosynthetic pathway affected various characteristics of the starch, starch was isolated from potato (Solanum tuberosum L.) tubers containing reduced amounts of the enzyme ADP-glucose pyrophosphorylase (AGPase). It was found that although the type of crystalline polymorph in the starch was not altered, the amylose content was severely reduced. In addition, amylopectin from the transgenic plants accumulated more relatively short chains than that from control plants and the sizes of starch granules were reduced. The starch granules from the transgenic plants contained a greater amount of granule-bound starch synthase enzyme, which led to an increase in the maximum activity of the enzyme per unit starch tested. The K(m) for ADP-glucose was, at most, only slightly altered in the transgenic lines. Potato plants containing reduced AGPase activity were also transformed with a bacterial gene coding for AGPase to test whether this enzyme can incorporate phosphate monoesters into amylopectin. A slight increase in phosphate contents in the starch in comparison with the untransformed control was found, but not in comparison with starch from the line with reduced AGPase activity into which the bacterial gene was transformed.Key words: ADP-glucose pyrophosphorylase. Amylopectin structure. Amylose. Solanum (starch. tuber). Starch granule size. Starch phosphorylation
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Affiliation(s)
- JR Lloyd
- Max-Planck Institute of Molecular Plant Physiology, Karl-Liebknecht Strasse 25, D-14476 Golm, Germany
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Keller R, Renz FS, Kossmann J. Antisense inhibition of the GDP-mannose pyrophosphorylase reduces the ascorbate content in transgenic plants leading to developmental changes during senescence. Plant J 1999; 19:131-141. [PMID: 10476060 DOI: 10.1046/j.1365-313x.1999.00507.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
GDP-mannose pyrophosphorylase (GMPase, EC 2.7.7.22) catalyses the synthesis of GDP-D-mannose and represents the first committed step in the formation of all guanosin-containing sugar nucleotides found in plants which are precursors for cell wall biosynthesis and, probably more important, the synthesis of ascorbate. A full-length cDNA encoding GMPase from S. tuberosum was isolated. Transgenic potato plants were generated in which the GMPase cDNA was introduced in antisense orientation to the 35S promoter. Transformants with reduced GMPase activity were selected. Transgenic plants were indistinguishable from the wild-type when held under tissue culture conditions, however, a major change was seen 10 weeks after transfer into soil. Transgenic plants showed dark spots on leaf veins and stems with this phenotype developing from the bottom to the top of the plant. In case of the line with the strongest reduction, all aerial parts finally dried out after 3 months in soil, in contrast to the wild-type plants which did not start to senesce at this time. This coincides with a reduction of ascorbate contents in the transgenic plants, which is in agreement with the recently proposed pathway of ascorbate biosynthesis. Furthermore, leaf cell walls of the transgenic potato plants had mannose contents that were reduced to 30-50% of the wild-type levels, whereas the composition of tuber cell walls was unchanged. The glycosylation pattern of proteins was unaffected by GMPase inhibition, as studied by affinoblot analysis.
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MESH Headings
- Amino Acid Sequence
- Ascorbic Acid/metabolism
- Carbohydrate Metabolism
- Carrier Proteins/metabolism
- Cell Wall/metabolism
- Cellulose/metabolism
- Cloning, Molecular
- Collectins
- DNA, Antisense/genetics
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Glucose/metabolism
- Glycosylation
- Lectins/metabolism
- Mannose/metabolism
- Molecular Sequence Data
- Nucleotidyltransferases/genetics
- Nucleotidyltransferases/metabolism
- Phenotype
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Lectins
- Plant Proteins/metabolism
- Plants, Genetically Modified
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Solanum tuberosum/enzymology
- Solanum tuberosum/genetics
- Solubility
- Starch/metabolism
- Tissue Distribution
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Affiliation(s)
- R Keller
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Golm/Potsdam, Germany
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Kossmann J, Abel GJ, Springer F, Lloyd JR, Willmitzer L. Cloning and functional analysis of a cDNA encoding a starch synthase from potato (Solanum tuberosum L.) that is predominantly expressed in leaf tissue. Planta 1999; 208:503-511. [PMID: 10420646 DOI: 10.1007/s004250050587] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three isoforms of starch synthase (SS) were shown to be present in soluble potato tuber extracts by activity staining after native gel electrophoresis. A cDNA encoding SSI from rice was used as a probe to clone a corresponding cDNA from potato. The deduced amino acid sequence identified the protein as an SS from potato with an M(r) of 70.6 kDa for the immature enzyme including its transit peptide. This novel isoform was designated SSI. An analysis of the expression pattern of the gene indicated that SSI is predominantly expressed in sink and source leaves, and, to a lower extent in tubers. In several independent transgenic potato lines, where the expression of SSI was repressed using the antisense approach, the activity of a specific SS isoform was reduced to non-detectable levels as determined through activity staining after native gel electrophoresis. The reduction in the amount of this isoform of SS did not lead to any detectable changes in starch structure, probably due to the fact that this isoform only represents a minor activity in potato tubers.
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Affiliation(s)
- J Kossmann
- Max-Planck-Institut für molekulare Pflanzenphysiologie, Golm, Germany.
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18
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Abstract
The cloning of a gene responsible for the phosphorylation of glucans has made it possible to genetically engineer the phosphorylation level of starches in higher plants. Through the manipulation of starch synthase activity, it is now also possible to genetically tailor the chain-length distribution in the amylopectin. Both findings will lead to the development of novel starches utilized as a renewable resource. The production of fructans on a large scale can also be envisioned for the near future.
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Affiliation(s)
- A G Heyer
- Max-Planck-Institute of Molecular Plant Physiology, Karl-Liebknecht-Strasse 24-25, D-14476 Golm, Germany.
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19
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Lloyd JR, Landschütze V, Kossmann J. Simultaneous antisense inhibition of two starch-synthase isoforms in potato tubers leads to accumulation of grossly modified amylopectin. Biochem J 1999. [PMID: 10024530 DOI: 10.1042/0264-6021:3380515] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A chimaeric antisense construct was used to reduce the activities of the two major starch-synthase isoforms in potato tubers simultaneously. A range of reductions in total starch-synthase activities were found in the resulting transgenic plants, up to a maximum of 90% inhibition. The reduction in starch-synthase activity had a profound effect on the starch granules, which became extremely distorted in appearance compared with the control lines. Analysis of the starch indicated that the amounts produced in the tubers, and the amylose content of the starch, were not affected by the reduction in activity. In order to understand why the starch granules were distorted, amylopectin was isolated and the constituent chain lengths analysed. This indicated that the amylopectin was very different to that of the control. It contained more chains of fewer than 15 glucose units in length, and fewer of between 15 and 80 glucose units. In addition, the amylopectin contained more very long chains. Amylopectin from plants repressed in just one of the activities of the two starch-synthase isoforms, which we have reported upon previously, were also analysed. Using a technique different to that used previously we show that both isoforms also affect the amylopectin, but in a way that is different to when both isoforms are repressed together.
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Affiliation(s)
- J R Lloyd
- Max Plank Institut für molekulare Pflanzenphysiologie, Karl-Liebknecht Strasse 25, 14476 Golm, Germany.
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20
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Romanov GA, Konstantinova TN, Sergeeva LI, Golyanovskaya SA, Kossmann J, Willmitzer L, Schmülling T, Aksenova NP. Morphology and tuber formation of in-vitro-grown potato plants harboring the yeast invertase gene and/or the rolC gene. Plant Cell Rep 1998; 18:318-324. [PMID: 30744243 DOI: 10.1007/s002990050579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Growth and tuber formation of transgenic potato plants (Solanum tuberosum cv. Désirée) harboring the yeast invertase gene and the rolC gene individually or in combination under the transcriptional control of the patatin promoter were investigated under different conditions in vitro. Plants expressing only the invertase gene were morphologically similar to control plants. rolC transgenic plants had an increased tiller number, improved root growth, and a higher total biomass. Tuber formation and growth were altered by the introduced transgenes. The sucrose requirement to induce tubers was shifted to lower or higher concentrations for invertase- or rolC-expressing clones, respectively. In addition, rolC plants formed tubers of altered morphology. A comparison with soil-grown plants showed that morphological parameters can be predicted to some extent from in vitro studies, while for reliable prescreening of parameters concerning tuber formation and growth, an optimization of currently used protocols is necessary.
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Affiliation(s)
- G A Romanov
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, R-127276 Moscow, Russia e-mail: , , , , , , RU
| | - T N Konstantinova
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, R-127276 Moscow, Russia e-mail: , , , , , , RU
| | - L I Sergeeva
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, R-127276 Moscow, Russia e-mail: , , , , , , RU
| | - S A Golyanovskaya
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, R-127276 Moscow, Russia e-mail: , , , , , , RU
| | - J Kossmann
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Golm b. Potsdam, Germany, , , , , , DE
| | - L Willmitzer
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Golm b. Potsdam, Germany, , , , , , DE
| | - T Schmülling
- Universität Tübingen, Allgemeine Genetik, Auf der Morgenstelle 28, D-72076 Tübingen, Germany e-mail: , , , , , , DE
| | - N P Aksenova
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, R-127276 Moscow, Russia e-mail: , , , , , , RU
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21
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Lorberth R, Ritte G, Willmitzer L, Kossmann J. Inhibition of a starch-granule-bound protein leads to modified starch and repression of cold sweetening. Nat Biotechnol 1998; 16:473-7. [PMID: 9592398 DOI: 10.1038/nbt0598-473] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have cloned a gene involved in starch metabolism that was identified by the ability of its product to bind to potato starch granules. Reduction in the protein level of transgenic potatoes leads to a reduction in the phosphate content of the starch. The complementary result is obtained when the protein is expressed in Escherichia coli, as this leads to an increased phosphate content of the glycogen. It is possible that this protein is responsible for the incorporation of phosphate into starch-like glucans, a process that is not understood at the biochemical level. The reduced phosphate content in potato starch has some secondary effects on its degradability, as the respective plants show a starch excess phenotype in leaves and a reduction in cold-sweetening in tubers.
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Affiliation(s)
- R Lorberth
- Institut für Genbiologische Forschung Berlin GmbH, Germany
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22
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Renz A, Schikora S, Schmid R, Kossmann J, Beck E. cDNA sequence and heterologous expression of monomeric spinach pullulanase: multiple isomeric forms arise from the same polypeptide. Biochem J 1998; 331 ( Pt 3):937-45. [PMID: 9560325 PMCID: PMC1219438 DOI: 10.1042/bj3310937] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The spinach pullulanase gene was cloned and sequenced using peptide sequences of the purified enzyme as a starting point and employing PCR techniques and cDNA library screening. Its open reading frame codes for a protein of 964 amino acids which represents a precursor of the pullulanase. The N-terminal transit peptide consists of 65 amino acids, and the mature protein, comprising 899 amino acids, has a calculated molecular mass of 99kDa. Pullulanase is a member of the alpha-amylase family. In addition to a characteristic catalytic (beta/alpha)8-barrel domain, it contains a domain, F, that is specific for branching and debranching enzymes. Pullulanase cDNA was expressed in Escherichia coli, and the purified protein was compared with the enzyme from spinach leaves. Identity of the two proteins was confirmed in terms of catalytic properties, N-terminal amino acid sequences and molecular masses. The pullulanase produced by E. coli showed the same microheterogeneity as the spinach leaf enzyme: it could be resolved into two substrate-induced forms by electrophoresis in amylopectin-containing polyacrylamide gels, and, in the absence of substrate, into several free forms (charge isomers) by isoelectric focusing or chromatofocusing. Rechromatofocusing of single free forms resulted in the originally observed pattern of molecular forms. However, heterogeneity of the protein disappeared on isoelectric focusing under completely denaturing conditions when only one protein band was observed. Post-translational modifications such as glycosylation and phosphorylation could be excluded as potential explanations for the protein heterogeneity. Therefore the microheterogeneity of spinach leaf pullulanase results from neither genetic variation nor post-translational modifications, but is a property of the single unmodified gene product. The different interconvertible forms of the pullulanase represent protein populations of different tertiary structure of the same polypeptide.
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Affiliation(s)
- A Renz
- Max-Planck-Institut für molekulare Pflanzenphysiologie, Karl-Liebknecht-Strasse 25, D 14476 Golm, Germany
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23
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Albrecht T, Greve B, Pusch K, Kossmann J, Buchner P, Wobus U, Steup M. Homodimers and heterodimers of Pho1-type phosphorylase isoforms in Solanum tuberosum L. as revealed by sequence-specific antibodies. Eur J Biochem 1998; 251:343-52. [PMID: 9492303 DOI: 10.1046/j.1432-1327.1998.2510343.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Higher plants possess two types of glucan phosphorylase (EC 2.4.1.1). One isozyme type, designated as Pho1, is located in the plastid whereas the other type, Pho2, is restricted to the cytosol. For Solanum tuberosum L. two Pho1 type phosphorylases have been sequenced [Nakano, K. & Fukui, T. (1986) J. Biol. Chem. 261, 8230-8236; Sonnewald, U., Basner, A., Greve, B. & Steup, M. (1995) Plant Mol. Biol. 27, 567-576]. Both proteins (referred to as Pho1a and Pho1b, respectively) are highly similar (81-84% amino acid identity over most parts of the two sequences) with the exception of the N-terminal transit peptide and the large insertion located between the N- and the C-terminal domains. In this communication antibodies that bind specifically to either Pho1a or Pho1b were used to study both isoforms at the protein level. The antibodies were applied to both potato tuber and leaf extracts following either denaturing or non-denaturing electrophoresis. Pho1a but not Pho1b was immunochemically detectable in tuber extracts whereas leaf extracts contained both the Pho1a and Pho1b protein. During denaturing electrophoresis the two antigens comigrated. When the leaf Pho1 isoforms were separated by affinity electrophoresis three bands of activity were resolved; all of them were recognized by the anti-Pho1a antibodies, but only two of these reacted with the anti-Pho1b antibodies. The isoform binding exclusively to the anti-Pho1a antibodies comigrated with the Pho1 isozyme from potato tubers. Immunoprecipitation experiments performed with anti-Pho1a antibodies removed the entire Pho1 phosphorylase activity from both tuber and leaf extracts. Addition of anti-Pho1b antibodies to tuber extracts did not affect the enzyme pattern, whereas in leaf extracts one isoform remained unchanged but the two other bands were strongly retarded. This indicates that the Pho1a protein is present in all three forms and Pho1b is associated with Pho1a. Association of Pho1a and Pho1b was further demonstrated by cross-linking experiments using bis(sulfosuccinimidyl)suberate as linker. Immunoprecipitation experiments were also performed using extracts of transformed Escherichia coli cells that expressed either Pho1a or Pho1b or both simultaneously. Under these conditions a homodimeric Pho1b phosphorylase was observed that had a lower electrophoretic mobility than the heterodimer from leaves. In leaves of transgenic potato plants antisense inhibition of the Pho1a gene affected the formation of (Pho1a)2 more strongly than that of the heterodimer. Thus, in leaves, Pho1a exists both as a homodimer, (Pho1a)2 and as heterodimer, (Pho1a-Pho1b); a part of it appears to be covalently modified. Pho1b, in the homodimeric form, is often below the limit of detection. In tubers the homodimer, (Pho1a)2, is the only detectable Pho1-type enzyme. To our knowledge this is the first report on a heterodimeric structure of plant phosphorylase.
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Affiliation(s)
- T Albrecht
- Institut für Biochemie und Molekulare Physiologie, Universität Potsdam, Germany
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24
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Buléon A, Gallant DJ, Bouchet B, Mouille G, D'Hulst C, Kossmann J, Ball S. Starches from A to C. Chlamydomonas reinhardtii as a model microbial system to investigate the biosynthesis of the plant amylopectin crystal. Plant Physiol 1997; 115:949-57. [PMID: 9390431 PMCID: PMC158558 DOI: 10.1104/pp.115.3.949] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Wide-angle powder x-ray diffraction analysis was carried out on starch extracted from wild-type and mutant Chlamydomonas reinhardtii cells. Strains containing no defective starch synthases as well as mutants carrying a disrupted granule-bound starch synthase structural gene displayed the A type of diffraction pattern with a high degree of crystallinity. Mutants carrying a defect for the major soluble starch synthase (SSS), SSS II, were characterized by a switch to the B type of diffraction pattern with very low crystallinity. Mutant strains carrying SSS I as the only glucan elongation enzyme regained some of their crystallinity but switched to the C type of diffraction pattern. Differential scanning calorimetry analysis correlated tightly with the x-ray diffraction results. Together with the electron microscopy analyses, these results establish C. reinhardtii as a microbial model system displaying all aspects of cereal starch synthesis and structure. We further show that SSS II is the major enzyme involved in the synthesis of crystalline structures in starch and demonstrate that SSS I alone builds a new type of amylopectin structure.
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Affiliation(s)
- A Buléon
- Institut National de la Recherche Agronomique, Centre de Recherches Agroalimentaires, Nantes, France
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25
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Duwenig E, Steup M, Kossmann J. Induction of genes encoding plastidic phosphorylase from spinach (Spinacia oleracea L.) and potato (Solanum tuberosum L.) by exogenously supplied carbohydrates in excised leaf discs. Planta 1997; 203:111-120. [PMID: 9299793 DOI: 10.1007/s004250050171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A full-length cDNA encoding plastidic phosphorylase (Pho1, EC 2.4.1.1) from spinach (Spinacia oleracea L.) has been isolated. Analysis of the deduced protein sequence revealed considerable homologies with the corresponding proteins from other plants, animals and prokaryotes. Escherichia coli cells carrying the entire cDNA for Pho1 expressed an active phosphorylase, which resembled the properties of the plastidic isozyme of spinach with respect to its low affinity to glycogen. Expression of Pho1 was studied in spinach at the level of both mRNA and enzyme activity. Plastidic phosphorylase was transcribed in flowers and leaves, but the highest Pho1 transcript levels were found in mature fruits/seeds. This is in agreement with the enzyme activity levels, as Pho1 activity was detected in all tissues tested, but the highest activity was also present in mature fruits/seeds. Since developing seeds are strong sink organs, which import sucrose and accumulate starch, this observation may indicate that plastidic phosphorylase plays a role in starch formation. The assumption has been tested further by a series of induction experiments in which leaf discs from spinach and potato plants were incubated with various carbohydrates. Following incubation, phosphorylase steady-state transcript levels as well as levels of neutral sugars and starch were determined. A similar induction behaviour was found for Pho1 from spinach and Pho1a from potato, indicating the presence of related sugar signal transduction pathways in these two species. In addition, the expression of Pho1a and Agp4 (the large submit of ADPglucose synthase) from potato seems to be partly coordinately regulated by carbohydrates. These data may suggest that the regulation of Pho1 expression is linked to the carbohydrate status of the respective tissue.
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Affiliation(s)
- E Duwenig
- Institut für Genbiologische Forschung Berlin GmbH, Berlin, Germany
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26
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Sonnewald U, Hajirezaei MR, Kossmann J, Heyer A, Trethewey RN, Willmitzer L. Increased potato tuber size resulting from apoplastic expression of a yeast invertase. Nat Biotechnol 1997. [PMID: 9255797 DOI: 10.1038/nbt0897-0794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The role of sucrose cleavage in determining sink strength in potato was investigated by generating transgenic potato plants that expressed a yeast invertase in either the cytosol or apoplast of tubers. Cytosolic localization gave rise to a reduction in tuber size and an increase in tuber number per plant whereas apoplastic targeting led to an increase in tuber size and a decrease in tuber number per plant. Sink organ size can be manipulated through modification of sucrose metabolism.
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Affiliation(s)
- U Sonnewald
- Institut für Genbiologische Forschung Berlin GmbH, Germany
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27
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Sonnewald U, Hajirezaei MR, Kossmann J, Heyer A, Trethewey RN, Willmitzer L. Increased potato tuber size resulting from apoplastic expression of a yeast invertase. Nat Biotechnol 1997; 15:794-7. [PMID: 9255797 DOI: 10.1038/nbt0897-794] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The role of sucrose cleavage in determining sink strength in potato was investigated by generating transgenic potato plants that expressed a yeast invertase in either the cytosol or apoplast of tubers. Cytosolic localization gave rise to a reduction in tuber size and an increase in tuber number per plant whereas apoplastic targeting led to an increase in tuber size and a decrease in tuber number per plant. Sink organ size can be manipulated through modification of sucrose metabolism.
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Affiliation(s)
- U Sonnewald
- Institut für Genbiologische Forschung Berlin GmbH, Germany
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28
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Duwenig E, Steup M, Willmitzer L, Kossmann J. Antisense inhibition of cytosolic phosphorylase in potato plants (Solanum tuberosum L.) affects tuber sprouting and flower formation with only little impact on carbohydrate metabolism. Plant J 1997; 12:323-333. [PMID: 9301085 DOI: 10.1046/j.1365-313x.1997.12020323.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To determine the function of cytosolic phosphorylase (Pho2; EC 2.4.1.1), transgenic potato plants were created in which the expression of the enzyme was inhibited by introducing a chimeric gene containing part of the coding region for cytosolic phosphorylase linked in antisense orientation to the 35S CaMV promotor. As revealed by Northern blot analysis and native polyacrylamide gel electrophoresis, the expression of cytosolic phosphorylase was strongly inhibited in both leaves and tubers of the transgenic plants. The transgenic plants propagated from stem cuttings were morphologically indiscernible from the wild-type. However, sprouting of the transgenic potato tubers was significantly altered: compared with the wild-type, transgenic tubers produced 2.4 to 8.1 times more sprouts. When cultivated in the greenhouse, transgenic seed tubers produced two to three times more shoots than the wild-type. Inflorescences appeared earlier in the resulting plants. Many of the transgenic plants flowered two or three times successively. Transgenic plants derived from seed tubers formed 1.6 to 2.4 times as many tubers per plant as untransformed controls. The size and dry matter content of the individual tubers was not noticeably altered. Tuber yield was significantly higher in the transgenic plants. As revealed by carbohydrate determination of freshly harvested and stored tubers, starch and sucrose pools were not noticeably affected by the antisense inhibition of cytosolic phosphorylase; however, glucose and fructose levels were markedly reduced after prolonged storage. These results favour the view that cytosolic phosphorylase does not participate in starch degradation. The possible links between the reduced levels of cytosolic phosphorylase and the observed changes with respect to sprouting and flowering are discussed.
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Affiliation(s)
- E Duwenig
- Institut für Genbiologische Forschung Berlin GmbH, Berlin, Germany
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29
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Büttcher V, Welsh T, Willmitzer L, Kossmann J. Cloning and characterization of the gene for amylosucrase from Neisseria polysaccharea: production of a linear alpha-1,4-glucan. J Bacteriol 1997; 179:3324-30. [PMID: 9150231 PMCID: PMC179114 DOI: 10.1128/jb.179.10.3324-3330.1997] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The gene for the amylosucrase from Neisseria polysaccharea (ATCC 43768) was cloned by use of a functional expression system in Escherichia coli XL1-Blue. The deduced amino acid sequence of the protein has homology to the sequences of the alpha-amylase class of enzymes, with the highest similarities being found to the sequences of the trehalose synthase from Pimelobacter sp. strain R48 (17) and amylomaltase from Thermotoga maritima (11). However, the regions of highest homology within the alpha-amylase class of enzymes, which are essential for the catalytic activity, are only scarcely found in the sequence of amylosucrase. By using the enzyme isolated from culture supernatants of transformed E. coli cells, it is possible to synthesize linear alpha-1,4-glucans from sucrose, indicating that the enzyme is not capable of producing alpha-1,6-glycosidic linkages on its own.
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Affiliation(s)
- V Büttcher
- Institut für Genbiologische Forschung GmbH Berlin, Germany
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30
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Abel GJ, Springer F, Willmitzer L, Kossmann J. Cloning and functional analysis of a cDNA encoding a novel 139 kDa starch synthase from potato (Solanum tuberosum L.). Plant J 1996; 10:981-91. [PMID: 9011082 DOI: 10.1046/j.1365-313x.1996.10060981.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Three isoforms of starch synthase were shown to be present in soluble potato tuber extracts by activity staining after native gel electrophoresis. An antibody directed against a domain conserved in starch synthases was used to clone a cDNA for one of these isoforms by screening a tuber-specific expression library. A partial cDNA of 2.6 kbp was obtained and used to isolate a full-length cDNA of 4167 bp. The deduced amino acid sequence identifies the protein as a novel type of starch synthase from potato with a molecular mass of 139.2 kDa for the immature enzyme including its transit peptide. This novel isoform was designated SS III. An analysis of the expression pattern of the gene indicates that SS III is equally expressed in tubers of different developmental stages as well as in sink and source leaves. In several independent transgenic potato lines, where the expression of SS III was repressed using the antisense approach, the activity of a specific starch synthase isoform was reduced to non-detectable levels as determined through activity staining after native gel electrophoresis. The reduction of this isoform of starch synthase leads to the synthesis of a structurally modified starch in the transgenic plants: there is a drastic change in granule morphology and an increased level of covalently linked phosphate.
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Affiliation(s)
- G J Abel
- Institut für Genbiologische Forschung Berlin GmbH, Germany
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31
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Kossmann J, Virgin I. High-amylose starch genes. Trends Food Sci Technol 1995. [DOI: 10.1016/s0924-2244(00)89182-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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32
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Bilger W, Fisahn J, Brummet W, Kossmann J, Willmitzer L. Violaxanthin Cycle Pigment Contents in Potato and Tobacco Plants with Genetically Reduced Photosynthetic Capacity. Plant Physiol 1995; 108:1479-1486. [PMID: 12228557 PMCID: PMC157527 DOI: 10.1104/pp.108.4.1479] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The influence of photosynthetic activity on the light-dependent adaptation of the pool size of the violaxanthin cycle pigments (violaxanthin + antheraxanthin + zeaxanthin) was studied in leaves of wild-type and transgenic potato (Solanum tuberosum L.) and tobacco (Nicotiana tabacum L.) plants. The genetically manipulated plants expressed an antisense mRNA coding for the chloroplastic fructose-bisphosphatase. Chl fluorescence quenching analysis revealed that the transformed plants exhibited a greatly impaired electron transport capacity. Light-limited and light-saturated non-photochemical quenching was strongly enhanced in the mRNA antisense potato plants. After 7 d of adaptation at various high photosynthetic photon flux densities (PPFDs), the violaxanthin cycle pool size increased, with a progressive elevation in PPFD. The pool size was higher for transgenic potatoes than for wild-type plants at all PPFDs. This difference vanished when pool size was correlated with the PPFD in excess of photosynthesis, as indicated by the epoxidation state of the violaxanthin cycle. Contrasting results were obtained for tobacco; in this species, photosynthetic activity did not affect the pool size. We conclude that regulatory mechanisms exist in potato, by which photosynthetic activity can influence the violaxanthin cycle pool size. Furthermore, evidence is provided that this adaptation of the pool size may contribute to an improved photoprotection of the photosynthetic apparatus under high-light conditions. However, tobacco plants seem to regulate their pool size independently of photosynthetic activity.
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Affiliation(s)
- W. Bilger
- Julius-von-Sachs-Institut fur Biowissenschaften, Lehrstuhl Botanik II, Mittlerer Dallenbergweg 64, 97082 Wurzburg, Germany (W. Bilger, W. Brummet)
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33
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Salbach PB, Specht E, von Hodenberg E, Kossmann J, Janssen-Timmen U, Schneider WJ, Hugger P, King WC, Glomset JA, Habenicht AJ. Differential low density lipoprotein receptor-dependent formation of eicosanoids in human blood-derived monocytes. Proc Natl Acad Sci U S A 1992; 89:2439-43. [PMID: 1312723 PMCID: PMC48673 DOI: 10.1073/pnas.89.6.2439] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We studied the ability of low density lipoproteins (LDLs) to provide arachidonic acid (AA) for eicosanoid biosynthesis in human blood-derived monocytes. When incubated in the presence of reconstituted LDL that contained cholesteryl [1-14C]arachidonate (recLDL-[14C]AA-CE), resting monocytes formed three labeled products of the prostaglandin (PG) H synthase pathway: 6-keto-PGF1 alpha, thromboxane B2, and PGE2. The amounts of these eicosanoids in response to recLDL-[14C]AA-CE were comparable to or exceeded those that were produced in response to the addition of 10 microM unesterified [1-14C]AA. By contrast, resting monocytes formed only small amounts of products of the 5-lipoxygenase pathway, leukotriene (LT) B4 and LTC4 from either recLDL-[14C]AA-CE or [14C]AA, indicating preferential utilization of AA in the PGH synthase reaction. However, they converted LDL-derived [14C]AA efficiently into LTB4 and LTC4, when they were first incubated with recLDL-[14C]AA-CE and subsequently stimulated with the chemotactic peptide N-formylmethionylleucylphenylalanine or the Ca2+ ionophore A23187. The classical LDL receptor pathway mediated the synthesis of all of the above eicosanoids from LDL but not from unesterified AA. These results demonstrate that the LDL receptor pathway preferentially promotes the synthesis of PGH synthase products in resting human blood-derived monocytes and that an additional mechanism is required to promote effective synthesis of 5-lipoxygenase pathway products from AA that originates in LDL cholesteryl esters.
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Affiliation(s)
- P B Salbach
- University of Heidelberg, Medical School, Department of Internal Medicine, Federal Republic of Germany
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Kossmann J, Visser RG, Müller-Röber B, Willmitzer L, Sonnewald U. Cloning and expression analysis of a potato cDNA that encodes branching enzyme: evidence for co-expression of starch biosynthetic genes. Mol Gen Genet 1991; 230:39-44. [PMID: 1745241 DOI: 10.1007/bf00290648] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
One of the key enzymes involved in the formation of amylopectin, which is the major component of starch, is branching enzyme. A cDNA for potato branching enzyme was cloned by screening a tuber-specific cDNA expression library using an antiserum directed against a denatured preparation of the protein. Complementation of an Escherichia coli strain deficient in branching enzyme was achieved using a construct derived from this clone. Analysis of the expression of the gene in potato revealed a close association with conditions favouring starch biosynthesis. The expression pattern of the gene coding for potato branching enzyme, as analyzed at the mRNA level, closely resembles that of AGPase S, a gene coding for one of the subunits of ADP-glucose pyrophosphorylase, which is the key regulatory enzyme in the starch biosynthetic pathway. This raises the possibility that enzymes involved in the pathway are coordinately regulated at the transcriptional level.
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Affiliation(s)
- J Kossmann
- Institut für Genbiologische Forschung, Berlin GmbH, Berlin, FRG
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Müller-Röber BT, Kossmann J, Hannah LC, Willmitzer L, Sonnewald U. One of two different ADP-glucose pyrophosphorylase genes from potato responds strongly to elevated levels of sucrose. Mol Gen Genet 1990; 224:136-46. [PMID: 1703626 DOI: 10.1007/bf00259460] [Citation(s) in RCA: 219] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The key regulatory step in starch biosynthesis is catalyzed by the tetrameric enzyme ADP-glucose pyrophosphorylase (AGPase). In leaf and storage tissue, the enzyme catalyzes the synthesis of ADP-glucose from glucose-1-phosphate and ATP. Using heterologous probes from maize, two sets (B and S) of cDNA clones encoding potato AGPase were isolated from a tuberspecific cDNA library. Sequence analysis revealed homology to other plant and bacterial sequences. Transcript sizes are 1.9 kb (AGPase B) and 2.1 kb (AGPase S). Northern blot experiments show that the two genes differ in their expression patterns in different organs. Furthermore, one of the genes (AGPase S) is strongly inducible by metabolizable carbohydrates (e.g. sucrose) at the RNA level. The accumulation of AGPase S mRNA was always found to be accompanied by an increase in starch content. This suggests a link between AGPase S expression and the status of a tissue as either a sink for or a source of carbohydrates. By contrast, expression of AGPase B is much less variable under various experimental conditions.
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Affiliation(s)
- B T Müller-Röber
- Institut für Genbiologische Forschung Berlin GmbH, Federal Republic of Germany
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Prat S, Frommer WB, Höfgen R, Keil M, Kossmann J, Köster-Töpfer M, Liu XJ, Müller B, Peña-Cortés H, Rocha-Sosa M. Gene expression during tuber development in potato plants. FEBS Lett 1990; 268:334-8. [PMID: 2200713 DOI: 10.1016/0014-5793(90)81281-r] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Potato tubers are modified stems that have differentiated into storage organs. Factors such as day-length, nitrogen supply, and levels of the phytohormones cytokinin and gibberellic acid, are known to control tuberization. Morphological changes during tuber initiation are accompanied by the accumulation of a characteristic set of proteins, thought to be involved in N-storage (i.e. patatin) or defense against microbial or insect attack (i.e. proteinase inhibitor II). Additionally, deposition of large amounts of starch occurs during tuber formation, which is paralleled by an increase in sucrose synthase and other enzymes involved in starch biosynthesis (i.e. ADP-glucose pyrophosphorylase, starch synthases, and branching enzyme). Potential controlling mechanisms for genes expressed during tuberization are discussed.
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Affiliation(s)
- S Prat
- Institut fur Genbiologische Forschung, Berlin GmbH, FRG
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Abstract
Two DNA fragments encoding the chromosomal and plasmid copies of the gene (cfxP) encoding phosphoribulokinase (PRK) from the chemoautotrophic bacterium Alcaligenes eutrophus, were sequenced and found to be highly homologous. The gene (cfxF) of another Calvin cycle enzyme, fructose-1,6-bisphosphatase (FBPase), was identified as terminating immediately upstream of cfxP, but was not completely contained on both fragments. A hypothetical, also incompletely contained, open reading frame starts closely downstream from cfxP. Genes cfxF, cfxP, and the third hypothetical gene seem to belong to the same operon. The cfxP genes encode highly homologous PRK isoenzyme subunits consisting of 292 aa residues with calculated Mrs of 33 319 (chromosomal PRKc) and 33 164 (plasmid-encoded PRKp). There is little overall sequence similarity between the bacterial and plant (spinach) PRK, apart from some structural motifs.
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Affiliation(s)
- J Kossmann
- Institut für Mikrobiologie, Georg-August-Universität Göttingen, F.R.G
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