Evaluation of amino acid content and nutritional quality of transgenic soybean seeds with high-level tryptophan accumulation

Ishimoto, Masao; Rahman, Syed Ajijur; Hanafy, Moemen S.; Khalafalla, Mutasim M.; El‐Shemy, Hany A.; Nakamoto, Yuya; Kita, Yoshio; Takanashi, Kojiro; Mizutani, Fumio; Murano, Yoshihiro; Funabashi, Tomoko; Miyagawa, Hisashi; Wakasa, K.

doi:10.1007/s11032-009-9334-3

Cited by 53 publications

(23 citation statements)

References 53 publications

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“…This mutated gene was introduced into several dicotyledonous species as well. Elevated Trp content was observed in potato tuber (Yamada et al 2004), soybean seeds (Ishimoto et al 2009) and Arabidopsis plants (Ishihara et al 2006). These findings unequivocally indicate that nullification of the feedback regulation of AS is critical for the accumulation of Trp in plants.…”

Section: Manipulation Of Trp Contentmentioning

confidence: 64%

Metabolic engineering of the tryptophan and phenylalanine biosynthetic pathways in rice

Wakasa

Ishihara

2009

Plant Biotechnology

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Tryptophan (Trp) and phenylalanine (Phe) are essential aromatic amino acids that animals cannot synthesize and are dependent on plants for their supply. In particular, Trp contributes to the nutritional quality of plant-based foods, and, along with lysine, methionine and threonine, it is used to supplement animal feeds. The other aromatic amino acids, Phe and tyrosine (Tyr), are used for the production of the low-calorie sweetener aspartame and the anti-Parkinson's disease drug L-dopa, respectively. The biosynthetic pathways for aromatic amino acids and their regulation have been extensively explored in bacteria because of their utility in the food and drug industry. In plants, aromatic amino acids are the precursors for a large variety of secondary metabolites including indole alkaloids, phenylpropanoids, flavonoids, and the phenolic polymer, lignin. One of plant growth regulators, indole-3-acetic acid (IAA), has also been shown to be biosynthesized from Trp. Thus, aromatic amino acids also play important roles in plant defense and development.In bacteria, fungi and plants, the three aromatic amino acids, Trp, Phe and Tyr, are synthesized from a common precursor, chorismate that originates from the shikimate pathway ( Figure 1). In bacteria, this pathway is almost exclusively used to produce aromatic amino acids for protein synthesis but, in higher plants, this pathway leads to the production of numerous aromatic secondary metabolites. The importance of this pathway in plants is indicated by the fact that about 20% of the carbon fixed by photosynthesis flow through this pathway. These facts strongly suggest that the modification of the shikimate and its derivative (or downstream) pathways may lead to dramatic changes in secondary metabolism. The enzymatic reactions in the biosynthetic pathway for aromatic amino acids seem to be identical in prokaryotes and eukaryotes but they apparently differ in the regulatory mechanisms for these pathways. For example, 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase, the enzyme that catalyzes the first reaction in the shikimate pathway, is not feedback inhibited by any of the aromatic amino acids in plants, but, each of the three DAHP synthase isoenzymes are Abstract Aromatic amino acids function as building blocks of proteins and as precursors for secondary metabolism. To obtain plants that accumulate tryptophan (Trp) and phenylalanine (Phe), we modified the biosynthetic pathways for these amino acids in rice and dicot species. By introducing a gene encoding a feedback-insensitive anthranilate synthase (AS) alpha subunit, we successfully obtained transgenic plants that over-accumulated Trp. In addition, we found mutant calli that accumulated Phe and Trp at high concentrations. The causal gene (mtr1-D) encoded an arogenate dehydratase (ADT)/prephenate dehydratase (PDT) that catalyzes the final reaction in Phe biosynthesis. The wild-type enzyme was sensitive to feedback inhibition by Phe, but the mutant enzyme encoded by mtr1-D was relatively insensitive. Further, ...

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Section: Manipulation Of Trp Contentmentioning

confidence: 64%

Metabolic engineering of the tryptophan and phenylalanine biosynthetic pathways in rice

Wakasa

Ishihara

2009

Plant Biotechnology

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“…Studies of the model plant Arabidopsis thaliana have focused on the roles of amino acids in nitrogen nutrition (Crawford and Forde, ), N‐assimilation (Coruzzi, ), metabolism and regulation (Hell and Wirtz, ; Ingle, ; Jander and Joshi, ; Tzin and Galili, ; Verslues and Sharma, ). Some key genes regulating free amino acid content have been identified in Arabidopsis (Angelovici et al ., ), tobacco (Maloney et al ., ), soya bean (Ishimoto et al ., ; Takahashi et al ., ), rapeseed (Moulin et al ., , ), rice (Kang et al ., ; Zhou et al ., ) and maize (Mertz et al ., ; Muehlbauer et al ., ; Shaver et al ., ; Wang et al ., , ). Opaque2 (O2) is an endosperm‐specific transcription factor belonging to the bZIP family, whose mutation could increase free lysine levels and enhance the overall nutritional value of grain by reducing the 22‐kD α‐ and β‐zein transcripts and proteins in maize (Hunter et al ., ; Kodrzycki et al ., ; Mertz et al ., ).…”

Section: Introductionmentioning

confidence: 99%

The genetic architecture of amino acids dissection by association and linkage analysis in maize

Deng

Luo

et al. 2017

Plant Biotechnology Journal

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SummaryAmino acids are both constituents of proteins, providing the essential nutrition for humans and animals, and signalling molecules regulating the growth and development of plants. Most cultivars of maize are deficient in essential amino acids such as lysine and tryptophan. Here, we measured the levels of 17 different total amino acids, and created 48 derived traits in mature kernels from a maize diversity inbred collection and three recombinant inbred line (RIL) populations. By GWAS, 247 and 281 significant loci were identified in two different environments, 5.1 and 4.4 loci for each trait, explaining 7.44% and 7.90% phenotypic variation for each locus in average, respectively. By linkage mapping, 89, 150 and 165 QTLs were identified in B73/By804, Kui3/B77 and Zong3/Yu87‐1 RIL populations, 2.0, 2.7 and 2.8 QTLs for each trait, explaining 13.6%, 16.4% and 21.4% phenotypic variation for each QTL in average, respectively. It implies that the genetic architecture of amino acids is relative simple and controlled by limited loci. About 43.2% of the loci identified by GWAS were verified by expression QTL, and 17 loci overlapped with mapped QTLs in the three RIL populations. GRMZM2G015534, GRMZM2G143008 and one QTL were further validated using molecular approaches. The amino acid biosynthetic and catabolic pathways were reconstructed on the basis of candidate genes proposed in this study. Our results provide insights into the genetic basis of amino acid biosynthesis in maize kernels and may facilitate marker‐based breeding for quality protein maize.

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“…The structures and HPLC‐MS/MS data of the nine components are shown in Table . Tryptophan ( 1 ) and phenolic compounds ( 2–9 ) were previously reported from soybean germplasms …”

Section: Resultsmentioning

confidence: 99%

Determination of the variations in levels of phenolic compounds in soybean (Glycine max Merr.) sprouts infected by anthracnose (Colletotrichum gloeosporioides )

Lee

Jeong

Cho

et al. 2013

J. Sci. Food Agric.

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Evaluation of amino acid content and nutritional quality of transgenic soybean seeds with high-level tryptophan accumulation

Cited by 53 publications

References 53 publications

Metabolic engineering of the tryptophan and phenylalanine biosynthetic pathways in rice

Metabolic engineering of the tryptophan and phenylalanine biosynthetic pathways in rice

The genetic architecture of amino acids dissection by association and linkage analysis in maize

Determination of the variations in levels of phenolic compounds in soybean (Glycine max Merr.) sprouts infected by anthracnose (Colletotrichum gloeosporioides )

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