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Amendola S, Kneip JS, Meyer F, Perozeni F, Cazzaniga S, Lauersen KJ, Ballottari M, Baier T. Metabolic Engineering for Efficient Ketocarotenoid Accumulation in the Green Microalga Chlamydomonas reinhardtii. ACS Synth Biol 2023; 12:820-831. [PMID: 36821819 DOI: 10.1021/acssynbio.2c00616] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Astaxanthin is a valuable ketocarotenoid with various pharmaceutical and nutraceutical applications. Green microalgae harbor natural capacities for pigment accumulation due to their 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway. Recently, a redesigned ß-carotene ketolase (BKT) was found to enable ketocarotenoid accumulation in the model microalga Chlamydomonas reinhardtii, and transformants exhibited reduced photoinhibition under high-light. Here, a systematic screening by synthetic transgene design of carotenoid pathway enzymes and overexpression from the nuclear genome identified phytoene synthase (PSY/crtB) as a bottleneck for carotenoid accumulation in C. reinhardtii. Increased ß-carotene hydroxylase (CHYB) activity was found to be essential for engineered astaxanthin accumulation. A combined BKT, crtB, and CHYB expression strategy resulted in a volumetric astaxanthin production of 9.5 ± 0.3 mg L-1 (4.5 ± 0.1 mg g-1 CDW) in mixotrophic and 23.5 mg L-1 (1.09 mg L-1 h-1) in high cell density conditions, a 4-fold increase compared to previous reports in C. reinhardtii. This work presents a systematic investigation of bottlenecks in astaxanthin accumulation in C. reinhardtii and the phototrophic green cell factory design for competitive use in industrial biotechnology.
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Affiliation(s)
- Sofia Amendola
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Jacob S Kneip
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Florian Meyer
- Genetics of Prokaryotes, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Federico Perozeni
- Department of Biotechnology, University of Verona, 37129 Verona, Italy
| | - Stefano Cazzaniga
- Department of Biotechnology, University of Verona, 37129 Verona, Italy
| | - Kyle J Lauersen
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Kingdom of Saudi Arabia
| | - Matteo Ballottari
- Department of Biotechnology, University of Verona, 37129 Verona, Italy
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
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Arias D, Arenas-M A, Flores-Ortiz C, Peirano C, Handford M, Stange C. Daucus carota DcPSY2 and DcLCYB1 as Tools for Carotenoid Metabolic Engineering to Improve the Nutritional Value of Fruits. FRONTIERS IN PLANT SCIENCE 2021; 12:677553. [PMID: 34512681 PMCID: PMC8427143 DOI: 10.3389/fpls.2021.677553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 05/26/2021] [Indexed: 06/13/2023]
Abstract
Carotenoids are pigments with important nutritional value in the human diet. As antioxidant molecules, they act as scavengers of free radicals enhancing immunity and preventing cancer and cardiovascular diseases. Moreover, α-carotene and β-carotene, the main carotenoids of carrots (Daucus carota) are precursors of vitamin A, whose deficiency in the diet can trigger night blindness and macular degeneration. With the aim of increasing the carotenoid content in fruit flesh, three key genes of the carotenoid pathway, phytoene synthase (DcPSY2) and lycopene cyclase (DcLCYB1) from carrots, and carotene desaturase (XdCrtI) from the yeast Xanthophyllomyces dendrorhous, were optimized for expression in apple and cloned under the Solanum chilense (tomatillo) polygalacturonase (PG) fruit specific promoter. A biotechnological platform was generated and functionally tested by subcellular localization, and single, double and triple combinations were both stably transformed in tomatoes (Solanum lycopersicum var. Microtom) and transiently transformed in Fuji apple fruit flesh (Malus domestica). We demonstrated the functionality of the S. chilense PG promoter by directing the expression of the transgenes specifically to fruits. Transgenic tomato fruits expressing DcPSY2, DcLCYB1, and DcPSY2-XdCRTI, produced 1.34, 2.0, and 1.99-fold more total carotenoids than wild-type fruits, respectively. Furthermore, transgenic tomatoes expressing DcLCYB1, DcPSY2-XdCRTI, and DcPSY2-XdCRTI-DcLCYB1 exhibited an increment in β-carotene levels of 2.5, 3.0, and 2.57-fold in comparison with wild-type fruits, respectively. Additionally, Fuji apple flesh agroinfiltrated with DcPSY2 and DcLCYB1 constructs showed a significant increase of 2.75 and 3.11-fold in total carotenoids and 5.11 and 5.84-fold in β-carotene, respectively whereas the expression of DcPSY2-XdCRTI and DcPSY2-XdCRTI-DcLCYB1 generated lower, but significant changes in the carotenoid profile of infiltrated apple flesh. The results in apple demonstrate that DcPSY2 and DcLCYB1 are suitable biotechnological genes to increase the carotenoid content in fruits of species with reduced amounts of these pigments.
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Affiliation(s)
- Daniela Arias
- Centro de Biología Molecular Vegetal, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Chile
| | - Anita Arenas-M
- Laboratorio de Nutrición y Genómica de Plantas, Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Carlos Flores-Ortiz
- Centro de Biología Molecular Vegetal, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Chile
| | - Clio Peirano
- Centro de Biología Molecular Vegetal, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Chile
| | - Michael Handford
- Centro de Biología Molecular Vegetal, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Chile
| | - Claudia Stange
- Centro de Biología Molecular Vegetal, Facultad de Ciencias, Universidad de Chile, Ñuñoa, Chile
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Díaz-Sánchez V, Estrada AF, Trautmann D, Al-Babili S, Avalos J. The gene carD encodes the aldehyde dehydrogenase responsible for neurosporaxanthin biosynthesis in Fusarium fujikuroi. FEBS J 2011; 278:3164-76. [PMID: 21749649 DOI: 10.1111/j.1742-4658.2011.08242.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neurosporaxanthin (β-apo-4'-carotenoic acid) biosynthesis has been studied in detail in the fungus Fusarium fujikuroi. The genes and enzymes for this biosynthetic pathway are known until the last enzymatic step, the oxidation of the aldehyde group of its precursor, β-apo-4'-carotenal. On the basis of sequence homology to Neurospora crassa YLO-1, which mediates the formation of apo-4'-lycopenoic acid from the corresponding aldehyde substrate, we cloned the carD gene of F. fujikuroi and investigated the activity of the encoded enzyme. In vitro assays performed with heterologously expressed protein showed the formation of neurosporaxanthin and other apocarotenoid acids from the corresponding apocarotenals. To confirm this function in vivo, we generated an Escherichia coli strain producing β-apo-4'-carotenal, which was converted into neurosporaxanthin upon expression of carD. Moreover, the carD function was substantiated by its targeted disruption in a F. fujikuroi carotenoid-overproducing strain, which resulted in the loss of neurosporaxanthin and the accumulation of β-apo-4'-carotenal, its derivative β-apo-4'-carotenol, and minor amounts of other carotenoids. Intermediates accumulated in the ΔcarD mutant suggest that the reactions leading to neurosporaxanthin in Neurospora and Fusarium are different in their order. In contrast to ylo-1 in N. crassa, carD mRNA content is enhanced by light, but to a lesser extent than other enzymatic genes of the F. fujikuroi carotenoid pathway. Furthermore, carD mRNA levels were higher in carotenoid-overproducing mutants, supporting a functional role for CarD in F. fujikuroi carotenogenesis. With the genetic and biochemical characterization of CarD, the whole neurosporaxanthin biosynthetic pathway of F. fujikuroi has been established.
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Affiliation(s)
- Violeta Díaz-Sánchez
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
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Deluc LG, Quilici DR, Decendit A, Grimplet J, Wheatley MD, Schlauch KA, Mérillon JM, Cushman JC, Cramer GR. Water deficit alters differentially metabolic pathways affecting important flavor and quality traits in grape berries of Cabernet Sauvignon and Chardonnay. BMC Genomics 2009; 10:212. [PMID: 19426499 PMCID: PMC2701440 DOI: 10.1186/1471-2164-10-212] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Accepted: 05/08/2009] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Water deficit has significant effects on grape berry composition resulting in improved wine quality by the enhancement of color, flavors, or aromas. While some pathways or enzymes affected by water deficit have been identified, little is known about the global effects of water deficit on grape berry metabolism. RESULTS The effects of long-term, seasonal water deficit on berries of Cabernet Sauvignon, a red-wine grape, and Chardonnay, a white-wine grape were analyzed by integrated transcript and metabolite profiling. Over the course of berry development, the steady-state transcript abundance of approximately 6,000 Unigenes differed significantly between the cultivars and the irrigation treatments. Water deficit most affected the phenylpropanoid, ABA, isoprenoid, carotenoid, amino acid and fatty acid metabolic pathways. Targeted metabolites were profiled to confirm putative changes in specific metabolic pathways. Water deficit activated the expression of numerous transcripts associated with glutamate and proline biosynthesis and some committed steps of the phenylpropanoid pathway that increased anthocyanin concentrations in Cabernet Sauvignon. In Chardonnay, water deficit activated parts of the phenylpropanoid, energy, carotenoid and isoprenoid metabolic pathways that contribute to increased concentrations of antheraxanthin, flavonols and aroma volatiles. Water deficit affected the ABA metabolic pathway in both cultivars. Berry ABA concentrations were highly correlated with 9-cis-epoxycarotenoid dioxygenase (NCED1) transcript abundance, whereas the mRNA expression of other NCED genes and ABA catabolic and glycosylation processes were largely unaffected. Water deficit nearly doubled ABA concentrations within berries of Cabernet Sauvignon, whereas it decreased ABA in Chardonnay at véraison and shortly thereafter. CONCLUSION The metabolic responses of grapes to water deficit varied with the cultivar and fruit pigmentation. Chardonnay berries, which lack any significant anthocyanin content, exhibited increased photoprotection mechanisms under water deficit conditions. Water deficit increased ABA, proline, sugar and anthocyanin concentrations in Cabernet Sauvignon, but not Chardonnay berries, consistent with the hypothesis that ABA enhanced accumulation of these compounds. Water deficit increased the transcript abundance of lipoxygenase and hydroperoxide lyase in fatty metabolism, a pathway known to affect berry and wine aromas. These changes in metabolism have important impacts on berry flavor and quality characteristics. Several of these metabolites are known to contribute to increased human-health benefits.
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Affiliation(s)
- Laurent G Deluc
- Department of Biochemistry and Molecular Biology, Mail Stop 200, University of Nevada, Reno, Nevada 89557, USA
| | - David R Quilici
- Department of Biochemistry and Molecular Biology, Mail Stop 200, University of Nevada, Reno, Nevada 89557, USA
| | - Alain Decendit
- Groupe d'Études des Substances Végétales à Activité Biologique, EA 3675, Institut des Sciences de la Vigne et du Vin, Université Victor Segalen Bordeaux 2, UFR Sciences Pharmaceutiques, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Jérôme Grimplet
- Department of Biochemistry and Molecular Biology, Mail Stop 200, University of Nevada, Reno, Nevada 89557, USA
| | - Matthew D Wheatley
- Department of Biochemistry and Molecular Biology, Mail Stop 200, University of Nevada, Reno, Nevada 89557, USA
| | - Karen A Schlauch
- Department of Biochemistry and Molecular Biology, Mail Stop 200, University of Nevada, Reno, Nevada 89557, USA
| | - Jean-Michel Mérillon
- Groupe d'Études des Substances Végétales à Activité Biologique, EA 3675, Institut des Sciences de la Vigne et du Vin, Université Victor Segalen Bordeaux 2, UFR Sciences Pharmaceutiques, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, Mail Stop 200, University of Nevada, Reno, Nevada 89557, USA
| | - Grant R Cramer
- Department of Biochemistry and Molecular Biology, Mail Stop 200, University of Nevada, Reno, Nevada 89557, USA
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Howitt CA, Cavanagh CR, Bowerman AF, Cazzonelli C, Rampling L, Mimica JL, Pogson BJ. Alternative splicing, activation of cryptic exons and amino acid substitutions in carotenoid biosynthetic genes are associated with lutein accumulation in wheat endosperm. Funct Integr Genomics 2009; 9:363-76. [PMID: 19330366 DOI: 10.1007/s10142-009-0121-3] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/09/2009] [Accepted: 03/08/2009] [Indexed: 11/30/2022]
Abstract
Endosperm carotenoid content in wheat is a primary determinant of flour colour and this affects both the nutritional value of the grain and its utility for different applications. Utilising wheat rice synteny two genes, epsilon-cyclase (epsilon-LCY) and phytoene synthase (Psy-A1), were identified as candidate genes for two of the QTL affecting lutein content in wheat endosperm. Analysis of the sequence changes in epsilon-LCY and Psy-A1 revealed possible causal mechanisms for both QTL. A point mutation in epsilon-LCY results in the substitution of a conserved amino acid in the high lutein allele. This substitution has been observed in high lutein-accumulating species from the Gentiales order. In Psy-A1, a sequence duplication at the end of exon 2 creates a new splice site and causes alternative splicing of the transcript and activation of a cryptic exon, resulting in four different transcripts: a wild-type transcript, two transcripts with early terminations and a transcript that would produce an in-frame, albeit longer protein. Only the wild-type splice variant produced an enzymatically active protein and its mRNA abundance was reduced by titration with the other splice variants. This reduction in wild-type mRNA is argued to result in a reduction in PSY protein and thus carotenoid content in wheat.
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Affiliation(s)
- Crispin A Howitt
- CSIRO Food Futures National Research Flagship, Canberra, Australia.
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Howitt CA, Pogson BJ. Carotenoid accumulation and function in seeds and non-green tissues. PLANT, CELL & ENVIRONMENT 2006; 29:435-45. [PMID: 17080597 DOI: 10.1111/j.1365-3040.2005.01492.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Carotenoids are plant pigments that function as antioxidants, hormone precursors, colourants and essential components of the photosynthetic apparatus. Carotenoids accumulate in nearly all types of plastids, not just the chloroplast, and are thus found in most plant organs and tissues, albeit at trace levels in some tissues. In this review we summarise the current knowledge of the carotenoid content of non-green plastids and discuss what is known about the regulation of their biosynthesis in roots, fruits, flowers, tubers and seeds. The emphasis is on food crops as carotenoids are essential components of human diets, primarily as some are precursors of vitamin A. The low carotenoid content of many staple foods, such as cereals, can exacerbate dietary deficiencies. The World Health Organisation has estimated that more than 100 million children are vitamin A-deficient and up to 500,000 of these children become blind each year. Many of these children die within 12 months of going blind. Thus, understanding the regulation of carotenoid accumulation in food crops, especially tubers and cereals, should facilitate improvements to nutritional value with potentially significant health benefits.
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Affiliation(s)
- Crispin A Howitt
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
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DellaPenna D, Pogson BJ. Vitamin synthesis in plants: tocopherols and carotenoids. ANNUAL REVIEW OF PLANT BIOLOGY 2006; 57:711-38. [PMID: 16669779 DOI: 10.1146/annurev.arplant.56.032604.144301] [Citation(s) in RCA: 455] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Carotenoids and tocopherols are the two most abundant groups of lipid-soluble antioxidants in chloroplasts. In addition to their many functional roles in photosynthetic organisms, these compounds are also essential components of animal diets, including humans. During the past decade, a near complete set of genes required for the synthesis of both classes of compounds in photosynthetic tissues has been identified, primarily as a result of molecular genetic and biochemical genomics-based approaches in the model organisms Arabidopsis thaliana and Synechocystis sp. PCC6803. Mutant analysis and transgenic studies in these and other systems have provided important insight into the regulation, activities, integration, and evolution of individual enzymes and are already providing a knowledge base for breeding and transgenic approaches to modify the types and levels of these important compounds in agricultural crops.
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Affiliation(s)
- Dean DellaPenna
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.
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