Engineering of the aspartate family biosynthetic pathway in barley (Hordeum vulgare L.) by transformation with heterologous genes encoding feed-back-insensitive aspartate kinase and dihydrodipicolinate synthase

Brinch-Pedersen, Henrik; Galili, Gad; Knudsen, Søren; Holm, Preben Bach

doi:10.1007/bf00020202

Cited by 81 publications

(38 citation statements)

References 47 publications

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“…The pTaPAPhy_a1-GUS-N and pTaPAPhy_b2-GUS-35Sterm plasmids were introduced into immature embryos of wheat cv Bobwhite using the DuPont PDS 1000 helium biolistic system, as described already (Brinch-Pedersen et al, 1996). Selection, regeneration, and identification of transgenic wheat plants were performed as described by Brinch-Pedersen et al (2000).…”

Section: Generation and Identification Of Transgenic Plantsmentioning

confidence: 99%

Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat, Barley, Maize, and Rice

et al. 2011

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Barley (Hordeum vulgare) and wheat (Triticum aestivum) possess significant phytase activity in the mature grains. Maize (Zea mays) and rice (Oryza sativa) possess little or virtually no preformed phytase activity in the mature grain and depend fully on de novo synthesis during germination. Here, it is demonstrated that wheat, barley, maize, and rice all possess purple acid phosphatase (PAP) genes that, expressed in Pichia pastoris, give fully functional phytases (PAPhys) with very similar enzyme kinetics. Preformed wheat PAPhy was localized to the protein crystalloid of the aleurone vacuole. Phylogenetic analyses indicated that PAPhys possess four conserved domains unique to the PAPhys. In barley and wheat, the PAPhy genes can be grouped as PAPhy_a or PAPhy_b isogenes (barley, HvPAPhy_a, HvPAPhy_b1, and HvPAPhy_b2; wheat, TaPAPhy_a1, TaPAPhy_a2, TaPAPhy_b1, and TaPAPhy_b2). In rice and maize, only the b type (OsPAPhy_b and ZmPAPhy_b, respectively) were identified. HvPAPhy_a and HvPAPhy_b1/b2 share 86% and TaPAPhya1/a2 and TaPAPhyb1/b2 share up to 90% (TaPAPhy_a2 and TaPAPhy_b2) identical amino acid sequences. despite of this, PAPhy_a and PAPhy_b isogenes are differentially expressed during grain development and germination. In wheat, it was demonstrated that a and b isogene expression is driven by different promoters (approximately 31% identity). TaPAPhy_a/b promoter reporter gene expression in transgenic grains and peptide mapping of TaPAPhy purified from wheat bran and germinating grains confirmed that the PAPhy_a isogene set present in wheat/barley but not in rice/maize is the origin of high phytase activity in mature grains.

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Section: Generation and Identification Of Transgenic Plantsmentioning

confidence: 99%

Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat, Barley, Maize, and Rice

et al. 2011

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“…Although manipulation of lysine biosynthesis has resulted in high free lysine for many plant species, the increases in seed free lysine content were lower as compared to other tissues (Perl et al 1992;Shaul and Galili 1993;Karchi et al 1994;Brinch-Pedersen et al 1996). It has been suggested that lysine catabolism plays a greater role in regulating free lysine concentration in developing seeds (Arruda et al 2000;Galili 2004;Stepansky et al 2006).…”

Section: Discussionmentioning

confidence: 98%

“…AK and DHDPS are both feedback inhibited by lysine, and so, represent the key regulators of plant lysine biosynthesis. Indeed, the expression of bacterial lysine feedback-insensitive DHDPS and/or AK in transgenic plants has generated high lysine potato, tobacco, canola, soybean, barley, Arabidopsis and maize (Perl et al 1992;Shaul and Galili 1993;Falco et al 1995;Brinch-Pedersen et al 1996;Zhu and Galili 2003;Huang et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Genetic manipulation of lysine catabolism in maize kernels

et al. 2008

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In plants, lysine catabolism is thought to be controlled by a bifunctional enzyme, lysine ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH). Lysine is converted to saccharopine, through condensation with alpha-ketoglutarate, by LKR, and subsequently to glutamate and alpha-aminoadipate-delta-semialdehyde by SDH. To investigate lysine catabolism in maize kernels, we generated transgenic plants with suppressed LKR/SDH activity in either endosperm or embryo. We found that the suppression of LKR/SDH in endosperm induced an increase in free lysine in developing endosperm, which peaked at 32 days after pollination. At later stages of kernel development, most of the free lysine was found in the embryo along with an elevated level of saccharopine. By combining endosperm LKR/SDH suppression with embryo LKR/SDH suppression through crosses, the saccharopine level in embryo was reduced and resulted in higher lysine accumulation in mature kernels. These results reveal new insights into how free lysine level is regulated and distributed in developing maize kernels and demonstrate the possibility of engineering high lysine corn via the suppression of lysine catabolism.

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“…Barley, like most grains, is deficient in the amino acids lysine and threonine, reducing food and feed quality. Brinch-Pedersen et al (1996) inserted lysine feedback insensitive forms of aspartate kinase and dihydrodipicolinate synthase into barley from Escherichia coli. Increased activity of these enzymes provided a twofold increase in lysine, arginine, and asparagines while reducing proline levels in half in T 0 and T 1 seeds.…”

Section: Nutritionmentioning

confidence: 99%

Barley

Ganeshan

Chibbar

Dahleen

et al. 2008

Compendium of Transgenic Crop Plants

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The value of barley ( Hordeum vulgare L.) has steadily gained importance over the years. The economic and consumer importance of barley is constantly being re‐evaluated as new market niches and end‐uses become evident. Improvement strategies have generally employed conventional breeding methods, including mutation‐breeding approaches. However newer technology‐driven improvement strategies offer promising new perspectives and include genetic transformation. Barley was generally recalcitrant to tissue culture and transformation, but is now fairly amenable to genetic transformation by particle bombardment as well as by Agrobacterium . Target traits for modification have encompassed malting, nutritional and disease‐resistance attributes in barley. However, with the emerging trends in high‐throughput genomic sequencing and the need for functional validation of cloned genes, genetic transformation of barley has become an important tool and use of approaches such as transposable elements mediated transformation offers the possibility of producing large numbers of transgenic barley plants. Approaches based on the RNAi technology are also likely to advance understanding of the functions of cloned genes in barley. In this chapter, there is a wide‐ranging discussion on barley genetic transformation, prospects, challenges and risk assessment and environmental concerns.

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Engineering of the aspartate family biosynthetic pathway in barley (Hordeum vulgare L.) by transformation with heterologous genes encoding feed-back-insensitive aspartate kinase and dihydrodipicolinate synthase

Cited by 81 publications

References 47 publications

Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat, Barley, Maize, and Rice

Cloning and Characterization of Purple Acid Phosphatase Phytases from Wheat, Barley, Maize, and Rice

Genetic manipulation of lysine catabolism in maize kernels

Barley

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