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Breeding Canola ( Brassica napus L.) for Protein in Feed and Food. PLANTS 2021; 10:plants10102220. [PMID: 34686029 PMCID: PMC8539702 DOI: 10.3390/plants10102220] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/03/2021] [Accepted: 10/11/2021] [Indexed: 01/12/2023]
Abstract
Interest in canola (Brassica napus L.). In response to this interest, scientists have been tasked with altering and optimizing the protein production chain to ensure canola proteins are safe for consumption and economical to produce. Specifically, the role of plant breeders in developing suitable varieties with the necessary protein profiles is crucial to this interdisciplinary endeavour. In this article, we aim to provide an overarching review of the canola protein chain from the perspective of a plant breeder, spanning from the genetic regulation of seed storage proteins in the crop to advancements of novel breeding technologies and their application in improving protein quality in canola. A review on the current uses of canola meal in animal husbandry is presented to underscore potential limitations for the consumption of canola meal in mammals. General discussions on the allergenic potential of canola proteins and the regulation of novel food products are provided to highlight some of the challenges that will be encountered on the road to commercialization and general acceptance of canola protein as a dietary protein source.
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Gacek K, Bartkowiak-Broda I, Batley J. Genetic and Molecular Regulation of Seed Storage Proteins (SSPs) to Improve Protein Nutritional Value of Oilseed Rape ( Brassica napus L.) Seeds. FRONTIERS IN PLANT SCIENCE 2018; 9:890. [PMID: 30013586 PMCID: PMC6036235 DOI: 10.3389/fpls.2018.00890] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/07/2018] [Indexed: 05/20/2023]
Abstract
The world-wide demand for additional protein sources for human nutrition and animal feed keeps rising due to rapidly growing world population. Oilseed rape is a second important oil producing crop and the by-product of the oil production is a protein rich meal. The protein in rapeseed meal finds its application in animal feed and various industrial purposes, but its improvement is of great interest, especially for non-ruminants and poultry feed. To be able to manipulate the quality and quantity of seed protein in oilseed rape, understanding genetic architecture of seed storage protein (SSPs) synthesis and accumulation in this crop species is of great interest. For this, application of modern molecular breeding tools such as whole genome sequencing, genotyping, association mapping, and genome editing methods implemented in oilseed rape seed protein improvement would be of great interest. This review examines current knowledge and opportunities to manipulate of SSPs in oilseed rape to improve its quality, quantity and digestibility.
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Affiliation(s)
- Katarzyna Gacek
- Oilseed Crops Research Centre, Plant Breeding and Acclimatization Institute-National Research Institute, Poznań, Poland
| | - Iwona Bartkowiak-Broda
- Oilseed Crops Research Centre, Plant Breeding and Acclimatization Institute-National Research Institute, Poznań, Poland
| | - Jacqueline Batley
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
- *Correspondence: Jacqueline Batley,
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Gudynaite-Savitch L, Johnson DA, Miki BLA. Strategies to mitigate transgene-promoter interactions. PLANT BIOTECHNOLOGY JOURNAL 2009; 7:472-485. [PMID: 19490507 DOI: 10.1111/j.1467-7652.2009.00416.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The expression pattern of tissue-specific promoters in transgenes can be influenced by promoter/enhancer elements employed for the expression of selectable marker genes or elements found in DNA flanking the insertion site. We have developed an analytical system in Arabidopsis thaliana to investigate strategies useful in blocking or reducing nonspecific interactions. These experiments confirm that the DNA configuration and the insertion of spacer DNA aid in the appropriate expression of tissue-specific promoters. It is also demonstrated that the novel tobacco cryptic promoter (tCUP), when used to replace the cauliflower mosaic virus (CaMV) 35S promoter/enhancer, does not show nonspecific interactions. Furthermore, it is shown that insulators isolated from yeast and animals may have potential application in plants. Our results may allow the design of strategies that, individually or in combination, can be used to minimize nonspecific interactions and to design vectors for individual tissue-specific promoters.
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Nesi N, Delourme R, Brégeon M, Falentin C, Renard M. Genetic and molecular approaches to improve nutritional value of Brassica napus L. seed. C R Biol 2008; 331:763-71. [PMID: 18926490 DOI: 10.1016/j.crvi.2008.07.018] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Oilseed rape (Brassica napus L.) is a major oil crop that also supplies proteins for the feed industry. In order to reduce total cost production, the objective is to increase oil yield while reducing crop inputs (especially nitrogen and pesticides). Concomitantly, it is necessary to anticipate specific uses (e.g., fatty acid composition) and to ensure the valorisation of the by-products (rapeseed meal). By the past, improvement of seed quality focused on fatty acid balance and low seed glucosinolate content. Current goals include the breeding of yellow-seeded rapeseed lines with high content of seed oil. The use of molecular tools and the exploitation of Arabidopsis knowledge will be presented and discussed.
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Affiliation(s)
- Nathalie Nesi
- INRA-Agrocampus Rennes-University of Rennes1 Joint Laboratory, UMR118, Plant Genetics and Biotechnologies, BP 35327, 35653 Le Rheu cedex, France.
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Beauregard M, Hefford MA. Enhancement of essential amino acid contents in crops by genetic engineering and protein design. PLANT BIOTECHNOLOGY JOURNAL 2006; 4:561-74. [PMID: 17309730 DOI: 10.1111/j.1467-7652.2006.00204.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The importance and urgency of providing humans and animals with quality proteins are reflected in the growing scientific and industrial interest in augmenting the nutritive value of the world's protein sources. Such nutritive value is determined by the protein content in 'essential amino acids', those that cannot be synthesized de novo and that must be supplied from the diet. It is the object of this review to discuss recent advances in the genetic modification of crops that aim to provide enhanced quantities of essential amino acids.
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Affiliation(s)
- Marc Beauregard
- Plant Biology Group, Département de Chimie-Biologie, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada, G9A 5H7.
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Bharali S, Chrungoo NK. Amino acid sequence of the 26 kDa subunit of legumin-type seed storage protein of common buckwheat (Fagopyrum esculentum Moench): molecular characterization and phylogenetic analysis. PHYTOCHEMISTRY 2003; 63:1-5. [PMID: 12657290 DOI: 10.1016/s0031-9422(02)00755-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The paper describes the amino acid sequence of a 26 kDa basic subunit of 13S globulin of common buckwheat (Fagopyrum esculentum Moench). The protein has 93 and 75% sequence homology with 11S globulin of Coffea arabica and beta subunit of 11S globulin of Cucurbita pepo respectively. The subunit has the "globally conserved" N-terminal sequence consisting of Gly-Ile-Asp-Glu and the cysteine at P7' from the proteolytic processing site. A conserved 7 residue domain of Pro-His-Trp-Asn-Ile-Asn-Ala, characteristic of basic subunits of legumins from non-leguminous angiosperms, is also present in this protein. A distinguishing features of this subunit is the relatively high level of lysine and methionine.
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Affiliation(s)
- Sangeeta Bharali
- Department of Botany, North Eastern Hill University Shillong 793 022, India
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Aragão F, Barros L, Sousa MD, Grossi de Sá M, Almeida E, Gander E, Rech E. Expression of a methionine-rich storage albumin from the Brazil nut (Bertholletia excelsa H.B.K., Lecythidaceae) in transgenic bean plants (Phaseolus vulgaris L., Fabaceae). Genet Mol Biol 1999. [DOI: 10.1590/s1415-47571999000300026] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Bean (Phaseolus vulgaris), an important component in the diet of people in developing countries, has low levels of the essential amino acid, methionine. We have attempted to correct this deficiency by introducing a transgene coding for a methionine-rich storage albumin from the Brazil nut via biolistic methods. The transgene's coding sequence was driven by a doubled 35S CaMV promoter and AMV enhancer sequences. The transgene was stable and correctly expressed in homozygous R2 to R5 seeds. In two of the five transgenic lines the methionine content was significantly increased (14 and 23%) over the values found in untransformed plants.
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Goossens A, Dillen W, De Clercq J, Van Montagu M, Angenon G. The arcelin-5 gene of Phaseolus vulgaris directs high seed-specific expression in transgenic Phaseolus acutifolius and Arabidopsis plants. PLANT PHYSIOLOGY 1999; 120:1095-104. [PMID: 10444093 PMCID: PMC59343 DOI: 10.1104/pp.120.4.1095] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/1999] [Accepted: 05/17/1999] [Indexed: 05/20/2023]
Abstract
The regulatory sequences of many genes encoding seed storage proteins have been used to drive seed-specific expression of a variety of proteins in transgenic plants. Because the levels at which these transgene-derived proteins accumulate are generally quite low, we investigated the utility of the arcelin-5 regulatory sequences in obtaining high seed-specific expression in transgenic plants. Arcelin-5 is an abundant seed protein found in some wild common bean (Phaseolus vulgaris L.) genotypes. Seeds of Arabidopsis and Tepary bean (Phaseolus acutifolius A. Gray) plants transformed with arcelin-5 gene constructs synthesized arcelin-5 to levels of 15% and 25% of the total protein content, respectively. To our knowledge, such high expression levels directed by a transgene have not been reported before. The transgenic plants also showed low plant-to-plant variation in arcelin expression. Complex transgene integration patterns, which often result in gene silencing effects, were not associated with reduced arcelin-5 expression. High transgene expression was the result of high mRNA steady-state levels and was restricted to seeds. This indicates that all requirements for high seed-specific expression are cis elements present in the cloned genomic arcelin-5 sequence and trans-acting factors that are available in Arabidopsis and Phaseolus spp., and thus probably in most dicotyledonous plants.
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Affiliation(s)
- A Goossens
- Laboratorium voor Genetica, Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, B-9000 Gent, Belgium
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de Lumen BO, Galvez AF, Revilleza MJ, Krenz DC. Molecular strategies to improve the nutritional quality of legume proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 464:117-26. [PMID: 10335390 DOI: 10.1007/978-1-4615-4729-7_10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Legume proteins are relatively deficient in the sulfur amino acids. Among the different strategies to increase the sulfur amino acid contents of legumes, we have chosen to increase the biosynthesis of endogenous, non-abundant sulfur-rich proteins we have identified in soybean seed. We identified and isolated an 8 kDa sulfur-rich protein from the albumin fraction of soybean seed. Subsequently, a cDNA designated Gm2S-1, has been isolated and characterized. The Gm2S-1 cDNA encodes a pre-proprotein that contains a signal peptide and a precursor protein that undergoes post-translational processing to yield the mature 8 kDa protein containing 7.8% methionine and 7.8% cysteine. The Gm2S-1 gene is an ideal candidate for overexpression to improve the nutritional quality of soybean and other legumes.
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Affiliation(s)
- B O de Lumen
- Division of Nutritional Sciences and Toxicology, University of California, Berkeley 94720-3104, USA
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Marcellino LH, Neshich G, Grossi de Sá MF, Krebbers E, Gander ES. Modified 2S albumins with improved tryptophan content are correctly expressed in transgenic tobacco plants. FEBS Lett 1996; 385:154-8. [PMID: 8647241 DOI: 10.1016/0014-5793(96)00375-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Brazil nut 2S albumins lack the essential amino acid tryptophan. In order to improve the protein's nutritional value and create a basis for structural investigations, three separate modified Brazil nut 2S albumin genes were constructed. The first mutant contains five consecutive tryptophan codons, while the other two modified genes encode proteins carrying single tryptophan residues at sites that will allow confirmation of the predicted protein structure through fluorescence quenching techniques. The modified genes, under the regulation of the CaMV 35S promoter, were introduced into Nicotiana tabacum. All three modified genes were correctly transcribed and the 2S albumin accumulated in the seeds of transgenic plants.
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Nordlee JA, Taylor SL, Townsend JA, Thomas LA, Bush RK. Identification of a Brazil-nut allergen in transgenic soybeans. N Engl J Med 1996; 334:688-92. [PMID: 8594427 DOI: 10.1056/nejm199603143341103] [Citation(s) in RCA: 445] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND The nutritional quality of soybeans (Glycine max) is compromised by a relative deficiency of methionine in the protein fraction of the seeds. To improve the nutritional quality, methionine-rich 2S albumin from the Brazil nut (Betholletia excelsa) has been introduced into transgenic soybeans. Since the Brazil nut is a known allergenic food, we assessed the allergenicity of the 2S albumin. METHODS The ability of proteins in transgenic and non-transgenic soybeans, Brazil nuts, and purified 2S albumin to bind to IgE in serum from subjects allergic to Brazil nuts was determined by radioallergosorbent tests (4 subjects) and sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (9 subjects) with immunoblotting and autoradiography. Three subjects also underwent skin-prick testing with extracts of soybean, transgenic soybean, and Brazil nut. RESULTS On radioallergosorbent testing of pooled serum from four subjects allergic to Brazil nuts, protein extracts of transgenic soybean inhibited binding of IgE to Brazil-nut proteins. On immunoblotting, serum IgE from eight of nine subjects bound to purified 2S albumin from the Brazil nut and the transgenic soybean. On skin-prick testing, three subjects had positive reactions to extracts of Brazil nut and transgenic soybean and negative reactions to soybean extract. CONCLUSIONS The 2S albumin is probably a major Brazil-nut allergen, and the transgenic soybeans analyzed in this study contain this protein. Our study show that an allergen from a food known to be allergenic can be transferred into another food by genetic engineering.
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Affiliation(s)
- J A Nordlee
- Department of Food Science and Technology, University of Nebraska, Lincoln, 68583-0919, USA
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Kohno-Murase J, Murase M, Ichikawa H, Imamura J. Improvement in the quality of seed storage protein by transformation of Brassica napus with an antisense gene for cruciferin. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1995; 91:627-31. [PMID: 24169890 DOI: 10.1007/bf00223289] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/1994] [Accepted: 02/03/1995] [Indexed: 05/03/2023]
Abstract
The levels of certain essential amino acids, in particular cysteine, lysine and methionine, in the seed storage protein of a commercial spring variety of rape, Brassica napus, have been increased by the introduction of an antisense gene for cruciferin, which is the most abundant storage protein in rapeseed. The antisense construct contained part of the cruA gene in an inverted orientation, and the gene was driven by the 5' flanking region of the gene for napin such that antisense RNA was expressed in a seed-specific manner. The construct was introduced by Agrobacterium-mediated gene transfer. In self-pollinated seeds (T1 seeds) of transgenic plants there was a reduction in the levels of the α1β1 and α2/3β2/3 subunits of cruciferin, whereas the level of the α4β4 subunit was unchanged. The total protein and lipid contents of transgenic seeds did not differ significantly from that of normal seeds. Seeds with reduced amounts of cruciferin accumulated higher amounts of napin than non-transformed seeds, but the level of oleosin was unaffected. Amino-acid analysis of the seed storage protein revealed that T1 seeds with reduced amounts of cruciferin contained higher relative levels of three essential amino acids, namely, lysine, methionine and cysteine, with increases of 10%, 8% and 32% over the respective levels in non-transgenic seeds (B. napus cv Westar).
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Affiliation(s)
- J Kohno-Murase
- Plantech Research Institute, 1000 Kamoshida-cho, Aoba-ku, Yokohama, 227, Kanagawa, Japan
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Fukushima D. Recent progress on biotechnology of soybean proteins and soybean protein food products. FOOD BIOTECHNOL 1994. [DOI: 10.1080/08905439409549872] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kohno-Murase J, Murase M, Ichikawa H, Imamura J. Effects of an antisense napin gene on seed storage compounds in transgenic Brassica napus seeds. PLANT MOLECULAR BIOLOGY 1994; 26:1115-24. [PMID: 7811970 DOI: 10.1007/bf00040693] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
To manipulate the quantity and quality of storage components in Brassica napus seeds, we have constructed an antisense gene for the storage protein napin. The antisense gene was driven by the 5'-flanking region of the B. napus napin gene to express antisense RNA in a seed-specific manner. Seeds of transgenic plants with antisense genes often contained reduced amounts of napin. In some transgenic plants, no accumulation of napin was observed. However, the total protein content of transgenic and wild-type seeds did not differ significantly. Seeds lacking napin accumulated 1.4 to 1.5 times more cruciferin than untransformed seeds, although the oleosin content was not affected. Fatty acid content and composition in the seeds of transgenic plants were also analyzed by gas chromatography. Though the total fatty acid content of the transformants was the same as that of non-transformants, there was a reduction in 18:1 contents and a concomitant increase of 18:2 in seeds with reduced napin levels. This observed change in fatty acid composition was inherited in the next generation.
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Saalbach I, Pickardt T, Machemehl F, Saalbach G, Schieder O, Müntz K. A chimeric gene encoding the methionine-rich 2S albumin of the Brazil nut (Bertholletia excelsa H.B.K.) is stably expressed and inherited in transgenic grain legumes. MOLECULAR & GENERAL GENETICS : MGG 1994; 242:226-36. [PMID: 8159174 DOI: 10.1007/bf00391017] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The coding region of the 2S albumin gene of Brazil nut (Bertholletia excelsa H.B.K.) was completely synthesized, placed under control of the cauliflower mosaic virus (CaMV) 35S promoter and inserted into the binary vector plasmid pGSGLUC1, thus giving rise to pGSGLUC1-2S. This was used for transformation of tobacco (Nicotiana tabacum L. cv. Petit Havanna) and of the grain legume Vicia narbonensis L., mediated by the supervirulent Agrobacterium tumefaciens strain EHA 101. Putative transformants were selected by screening for neomycin phosphotransferase (NPT II) and beta-glucuronidase (GUS) activities. Transgenic plants were grown until flowering and fruiting occurred. The presence of the foreign gene was confirmed by Southern analysis. GUS activity was found in all organs of the regenerated transgenic tobacco and legume plants, including the seeds. In the legume, the highest expression levels of the CaMV 35S promoter-controlled 2S albumin gene were observed in leaves and roots. 2S albumin was localized in the vacuoles of leaf mesophyll cells of transgenic tobacco. The Brazil nut protein was present in the 2S fraction after gel filtration chromatography of the legume seed proteins and could be clearly identified by immunoblotting. Analysis of seeds from the R2 progenies of the legume and of transgenic tobacco plants revealed Mendelian inheritance of the foreign gene. Agrobacterium rhizogenes strain RifR 15834 harbouring the binary vector pGSGLUC1-2S was also used to transform Pisum sativum L. and Vicia faba L. Hairy roots expressed the 2S albumin-specific gene. Several shoots were raised but they never completely rooted and no fertile plants were obtained from these transformants.
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Affiliation(s)
- I Saalbach
- Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany
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Melo VMM, Xavier‐Filho J, Lima MS, Prouvost‐Danon A. Allergenicity and tolerance to proteins from brazil nut(Bertholletia excelsaH. B. K.). FOOD AGR IMMUNOL 1994. [DOI: 10.1080/09540109409354829] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Raina A, Datta A. Molecular cloning of a gene encoding a seed-specific protein with nutritionally balanced amino acid composition from Amaranthus. Proc Natl Acad Sci U S A 1992; 89:11774-8. [PMID: 1465397 PMCID: PMC50639 DOI: 10.1073/pnas.89.24.11774] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
An albumin with a well-balanced amino acid composition and high levels of the essential amino acids was purified to homogeneity from the mature seeds of Amaranthus hypochondriacus. The amino acid composition of this protein is comparable to the World Health Organization recommended values for a highly nutritional protein. The protein is a 35-kDa monomer with four isoforms that can be separated by chromatofocusing. Antibodies raised against one of the isoforms, AmA1, cross-reacted with the other three isoforms. Affinity-purified AmA1 antibodies were used to isolate cDNA clones from a developing-seed expression library. The six immunopositive recombinants obtained were found to be related. The cDNA of the largest clone (1.2 kilobases) has a single major open reading frame corresponding to a 304-amino acid polypeptide. The clone was confirmed by hybrid-selected translation and immunoprecipitation. The size of the immunoprecipitated product was identical to the mature protein. Analysis of RNA and protein in developing seeds showed that AmA1 is synthesized during early embryogenesis, reaching a maximum by midmaturation. No RNA was detected in 1-day-old seedlings although the protein showed delayed breakdown on germination. Expression of the AmA1 gene was found to be seed-specific, as no protein or RNA was detected in other plant tissues.
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Affiliation(s)
- A Raina
- Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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Altenbach SB, Kuo CC, Staraci LC, Pearson KW, Wainwright C, Georgescu A, Townsend J. Accumulation of a Brazil nut albumin in seeds of transgenic canola results in enhanced levels of seed protein methionine. PLANT MOLECULAR BIOLOGY 1992; 18:235-45. [PMID: 1731986 DOI: 10.1007/bf00034952] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We have increased the methionine content of the seed proteins of a commercial winter variety of canola by expressing a chimeric gene encoding a methionine-rich seed protein from Brazil nut in the seeds of transgenic plants. Transgenic canola seeds accumulate the heterologous methionine-rich protein at levels which range from 1.7% to 4.0% of the total seed protein and contain up to 33% more methionine. The precursor of the methionine-rich protein is processed correctly in the seeds, resulting in the appearance of the mature protein in the 2S protein fraction. The 2S methionine-rich protein accumulates in the transgenic seeds at the same time in development as the canola 11S seed proteins and disappears rapidly upon germination of the seed. The increase in methionine in the canola seed proteins should increase the value of canola meal which is used in animal feed formulations.
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