Mutation of a Rice Gene Encoding a Phenylalanine Biosynthetic Enzyme Results in Accumulation of Phenylalanine and Tryptophan

Yamada, Tetsuya; Mizutani, Fumio; Kasai, Koji; Fukuoka, Shuichi; Kitamura, Kazuya; Tozawa, Yuzuru; Miyagawa, Hisashi; Wakasa, K.

doi:10.1105/tpc.107.057455

Cited by 96 publications

(97 citation statements)

References 62 publications

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“…This is in sharp contrast to Phe metabolism. Metabolic profiling of the rice Mtr1 callus revealed the accumulation of multiple Phe-derived secondary metabolites at a substantially high concentration (Yamada et al 2008). The strict control of Trp metabolism might be associated with the fact that Trp is one of the most biosynthetically expensive amino acids, and plants may have developed a mechanism to prevent precious metabolites from unnecessary utilization as suggested by Matsuda et al (in press).…”

Section: Resultsmentioning

confidence: 99%

“…However, feedback inhibition of AS activity by Trp did not differ between Mtr1 and the wild-type variety Norin 8 (Yamada et al 2008). The metabolic profile of Mtr1 calli revealed accumulation of multiple compounds at high levels relative to Norin 8 (Yamada et al 2008). Chemical structures of those eight compounds were determined by spectroscopic analyses.…”

Section: Phe Biosynthesis Is Also Controlled By Feedback Regulationmentioning

confidence: 99%

“…The candidate for Mtr1 mutant gene (mtr1-D) that had been annotaited as a putative PDT was isolated by positional cloning (Yamada et al 2008). The mtr1-D gene contained a single base substitution at nucleotide position 893 as compared to the corresponding genes in Norin 8 and Nipponbare.…”

Section: Phe Biosynthesis Is Also Controlled By Feedback Regulationmentioning

confidence: 99%

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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: Resultsmentioning

confidence: 99%

Section: Phe Biosynthesis Is Also Controlled By Feedback Regulationmentioning

confidence: 99%

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Metabolic engineering of the tryptophan and phenylalanine biosynthetic pathways in rice

Wakasa

Ishihara

2009

Plant Biotechnology

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“…S1). It remains to be investigated if there is a dedicated PDT with strict specificity for prephenate catalysing this reaction, or if plants rely on one or more of the known ADTs that can use prephenate as substrate at low catalytic efficiencies 15,16,40 . In petunia, PhADT2 and PhADT3, but not PhADT1, are capable of utilizing prephenate 16 .…”

Section: Discussionmentioning

confidence: 99%

An alternative pathway contributes to phenylalanine biosynthesis in plants via a cytosolic tyrosine:phenylpyruvate aminotransferase

et al. 2013

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Phenylalanine is a vital component of proteins in all living organisms, and in plants is a precursor for thousands of additional metabolites. Animals are incapable of synthesizing phenylalanine and must primarily obtain it directly or indirectly from plants. Although plants can synthesize phenylalanine in plastids through arogenate, the contribution of an alternative pathway via phenylpyruvate, as occurs in most microbes, has not been demonstrated. Here we show that plants also utilize a microbial-like phenylpyruvate pathway to produce phenylalanine, and flux through this route is increased when the entry point to the arogenate pathway is limiting. Unexpectedly, we find the plant phenylpyruvate pathway utilizes a cytosolic aminotransferase that links the coordinated catabolism of tyrosine to serve as the amino donor, thus interconnecting the extra-plastidial metabolism of these amino acids. This discovery uncovers another level of complexity in the plant aromatic amino acid regulatory network, unveiling new targets for metabolic engineering.

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“…Transcriptional control was shown for 3-deoxy-D-arabinose-heptulosonate (DHAP) synthase [Gientka & Duszkiewicz-Reinhard, 2009], whereas arogenate and prephenate dehydratase are inhibited by phenylalanine, one end-product of the pathway [Yamada et al, 2008]. The plastidal location of two elusive steps of the shikimate pathway, arogenate dehydratase and dehydrogenase, leading to phenylalanine and tyrosine biosynthesis has recently been proven [Rippert et al, 2009].…”

Section: Effect Of Different Factors On Biosyn-thesis Of Secondary Mementioning

confidence: 99%

Current Approaches for Enhanced Expression of Secondary Metabolites as Bioactive Compounds in Plants for Agronomic and Human Health Purposes

Jiménez-García¹,

Vazquez-Cruz²,

Guevara-González³

et al. 2013

Pol. J. Food Nutr. Sci.

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The study of secondary metabolism in plants is an important source for the discovery of bioactive compounds with a wide range of applications. Today these bioactive compounds derived from plants are important drugs such as antibiotics, and agrochemicals substitutes, they also have been economically important as fl avors and fragrances, dyes and pigments, and food preservatives. Many of the drugs sold today are synthetic modifi cations of naturally obtained substances. There is no rigid scheme for classifying secondary metabolites, but they can be divided into different groups based on their chemical components, function and biosynthesis: terpenoids and steroids, fatty acid-derived substances and polyketides, alkaloids, phenolic compounds, non-ribosomal polypeptides and enzyme cofactors. The increasing commercial importance of these chemical compounds has resulted in a great interest in secondary metabolism, particularly the possibility of altering the production of bioactive plant metabolites by means of tissue culture technology and metabolomics. In today's world the use of bioactive compounds derived from plants plays an important role in pharmaceutical applications. This review presents information about these metabolites and their applications as well as their importance in agronomy and bioactive effects on human health as nutraceuticals. This review includes also the new tendencies to produce these bioactive compounds under different stresses conditions such as biotic and abiotic stress that could be included in production systems.

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Mutation of a Rice Gene Encoding a Phenylalanine Biosynthetic Enzyme Results in Accumulation of Phenylalanine and Tryptophan

Cited by 96 publications

References 62 publications

Metabolic engineering of the tryptophan and phenylalanine biosynthetic pathways in rice

Metabolic engineering of the tryptophan and phenylalanine biosynthetic pathways in rice

An alternative pathway contributes to phenylalanine biosynthesis in plants via a cytosolic tyrosine:phenylpyruvate aminotransferase

Current Approaches for Enhanced Expression of Secondary Metabolites as Bioactive Compounds in Plants for Agronomic and Human Health Purposes

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