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Demidov, Dimitri; Horstmann, Christian; Meixner, Martin; Pickardt, Thomas; Saalbach, Isolde; Galili, Gad; Müntz, Klaus

doi:10.1023/a:1022814506153

Cited by 34 publications

(6 citation statements)

References 36 publications

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“…However, this is unlike the results found in narbon bean seeds, which expressed the feedback-insensitive bacterial aspartate kinase and the 2S albumin of Brazil nut (Demidov et al, 2003). In these seeds, the level of methionine increased up to 2.4-fold compared to control seeds, and they also had more methionine than their parents: 10-12% more than those expressing the aspartate kinase and 80% more than those expressing Brazil nut (Demidov et al, 2003).…”

Section: Discussioncontrasting

confidence: 87%

“…Indeed, overexpressing the A. thaliana CGS (AtCGS), or seed-specific expression of AtCGS, leads to significantly higher levels of free methionine (Kim et al, 2002;Di et al, 2003;Dancs et al, 2008;Hanafy et al, 2013;Song et al, 2013;Cohen et al, 2014;Cohen et al, 2016b). High elevations of free methionine in seeds were also obtained when other genes from the biochemical pathways of the aspartate family and the sulfur assimilation pathway were used (Karchi et al, 1993;Demidov et al, 2003;Kim et al, 2012;Nguyen et al, 2012;Planta et al, 2017;Xiang et al, 2018). In order to achieve a high expression in seeds during the production of proteins, the heterologous genes were fused to the promoters of seed-storage proteins that express the genes in the last stage of seed development when most of the amino acids are formed (e.g., Karchi et al, 1993;Kim et al, 2012;Nguyen et al, 2012;Matityahu et al, 2013;Amir et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

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The Level of Methionine Residues in Storage Proteins Is the Main Limiting Factor of Protein-Bound-Methionine Accumulation in Arabidopsis Seeds

et al. 2020

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The low level of methionine, an essential sulfur-containing amino acid, limits the nutritional quality of seeds. Two main factors can control the level of protein-bound methionine: the level of free methionine that limits protein accumulation and the methionine residues inside the storage proteins. To reveal the main limiting factor, we generated transgenic Arabidopsis thaliana seed-specific plants expressing the methionine-rich sunflower seed storage ( SSA ) protein (A1/A2). The contents of protein-bound methionine in the water-soluble protein fraction that includes the SSA in A1/A2 were 5.3- and 10.5-fold, respectively, compared to control, an empty vector (EV). This suggests that free methionine can support this accumulation. To elucidate if the level of free methionine could be increased further in the protein-bound methionine, these lines were crossed with previously characterized plants having higher levels of free methionine in seeds (called SSE). The progenies of the crosses (A1S, A2S) exhibited the highest level of protein-bound methionine, but this level did not differ significantly from A2, suggesting that all the methionine residues of A2 were filled with methionine. It also suggests that the content of methionine residues in the storage proteins is the main limiting factor. The results also proposed that the storage proteins can change their content in response to high levels of free methionine or SSA. This was assumed since the water-soluble protein fraction was highest in A1S/A2S as well as in SSE compared to EV and A1/A2. By using these seeds, we also aimed at gaining more knowledge about the link between high free methionine and the levels of metabolites that usually accumulate during abiotic stresses. This putative connection was derived from a previous analysis of SSE. The results of metabolic profiling showed that the levels of 29 and 20 out of the 56 metabolites were significantly higher in SSE and A1, respectively, that had higher level of free methionine, compared A1S/A2S, which had lower free methionine levels. This suggests a strong link between high free methionine and the accumulation of stress-associated metabolites.

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Section: Discussioncontrasting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

The Level of Methionine Residues in Storage Proteins Is the Main Limiting Factor of Protein-Bound-Methionine Accumulation in Arabidopsis Seeds

et al. 2020

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“…The obvious solution of combining the addition of a sulphur sink with modification of the sulphur amino acid biosynthetic pathway is the subject of current work. Some success has been reported; for example, expression of both the Brazil nut 2S albumin and a feedbackinsensitive aspartate kinase gave additive increases in total methionine in seeds of GM narbon beans, although most of the effect was apparently due to the Brazil nut protein (Demidov et al 2003). More recently, it has been reported that co-expression of an Arabidopsis CGS enzyme with a sulphur-rich zein in GM alfalfa leaves increased accumulation of the zein when compared with its expression alone in GM alfalfa (Bagga et al 2005).…”

Section: Improving the Essential Amino Acid Balance In Plant Proteins Used For Food And Feedmentioning

confidence: 99%

Genetic contributions to agricultural sustainability

Dennis

Ellis

Green

et al. 2007

Phil. Trans. R. Soc. B

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The current tools of enquiry into the structure and operation of the plant genome have provided us with an understanding of plant development and function far beyond the state of knowledge that we had previously. We know about key genetic controls repressing or stimulating the cascades of gene expression that move a plant through stages in its life cycle, facilitating the morphogenesis of vegetative and reproductive tissues and organs. The new technologies are enabling the identification of key gene activity responses to the range of biotic and abiotic challenges experienced by plants. In the past, plant breeders produced new varieties with changes in the phases of development, modifications of plant architecture and improved levels of tolerance and resistance to environmental and biotic challenges by identifying the required phenotypes in a few plants among the large numbers of plants in a breeding population. Now our increased knowledge and powerful gene sequence-based diagnostics provide plant breeders with more precise selection objectives and assays to operate in rationally planned crop improvement programmes. We can expect yield potential to increase and harvested product quality portfolios to better fit an increasing diversity of market requirements. The new genetics will connect agriculture to sectors beyond the food, feed and fibre industries; agri-business will contribute to public health and will provide high-value products to the pharmaceutical industry as well as to industries previously based on petroleum feedstocks and chemical modification processes.

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“…Here we generated double transgenic lines, containing both increased sink strength ("pull") for methionine and increased cystine/methionine biosynthetic enzyme activity ("push"), to test whether combining these traits would result in a synergistic increase in rice seed methionine. This combinatorial approach has proved successful in maize, narbon bean, and potato (Demidov et al, 2003;Dancs et al, 2008;Planta et al, 2017), but to our knowledge, this is the first report to combine increased sink and source strength for methionine in rice. Specifically, we crossed SSA transgenic plants with the SAT transgenic line or the CGS transgenic line that we deemed most promising.…”

Section: Introductionmentioning

confidence: 96%