Isolation of a cDNA from tomato coding for an unregulated, cytosolic chorismate mutase

Eberhard, Jenny; Bischoff, Markus; Raesecke, Hanns R.; Amrhein, Nikolaus; Schmid, Jürg

doi:10.1007/bf00019479

Cited by 18 publications

(10 citation statements)

References 23 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5). This resembles the results obtained with a chorismate mutase cDNA present in tomato pulp, roots and leaves (Eberhard et al, 1996). The above-mentioned results strengthen the hypothesis that chorismate mutase levels in photosynthetically inactive organs exceed those in photosynthetically active tissue, since availability for secondary metabolism is greater in the former (Görlach et al, 1994).…”

Section: Article In Presssupporting

confidence: 87%

Identification of genes differentially expressed during ripening of banana

Manrique¹,

Ramírez-López²,

Ibarra-Laclette³

et al. 2007

Journal of Plant Physiology

View full text Add to dashboard Cite

Section: Article In Presssupporting

confidence: 87%

Identification of genes differentially expressed during ripening of banana

Manrique¹,

Ramírez-López²,

Ibarra-Laclette³

et al. 2007

Journal of Plant Physiology

View full text Add to dashboard Cite

“…Moreover, two additional loci for GGPS were identified here. For the SK pathway, enzyme-encoding genes involved in reactions upstream of the prephenate intermediate have already been reported in tomato (Gasser et al , 1988; Schmid et al , 1992; Görlach et al , 1993, 1995; Eberhard et al , 1996; Bischoff et al , 1996, 2001). Moreover, novel loci for SDH/DHQ and CM were identified, whilst the loci encoding PAT, TyrA, and TAT were first described in tomato.…”

Section: Discussionmentioning

confidence: 96%

Genetic dissection of vitamin E biosynthesis in tomato

Almeida

Quadrana

Ramón

et al. 2011

Journal of Experimental Botany

View full text Add to dashboard Cite

Vegetables are critical for human health as they are a source of multiple vitamins including vitamin E (VTE). In plants, the synthesis of VTE compounds, tocopherol and tocotrienol, derives from precursors of the shikimate and methylerythritol phosphate pathways. Quantitative trait loci (QTL) for α-tocopherol content in ripe fruit have previously been determined in an Solanum pennellii tomato introgression line population. In this work, variations of tocopherol isoforms (α, β, γ, and δ) in ripe fruits of these lines were studied. In parallel all tomato genes structurally associated with VTE biosynthesis were identified and mapped. Previously identified VTE QTL on chromosomes 6 and 9 were confirmed whilst novel ones were identified on chromosomes 7 and 8. Integrated analysis at the metabolic, genetic and genomic levels allowed us to propose 16 candidate loci putatively affecting tocopherol content in tomato. A comparative analysis revealed polymorphisms at nucleotide and amino acid levels between Solanum lycopersicum and S. pennellii candidate alleles. Moreover, evolutionary analyses showed the presence of codons evolving under both neutral and positive selection, which may explain the phenotypic differences between species. These data represent an important step in understanding the genetic determinants of VTE natural variation in tomato fruit and as such in the ability to improve the content of this important nutriceutical.

show abstract

“…Without complementing in vivo studies, our data do not permit any conclusion concerning the quantitative importance of PAL and TAL activities in maize, but with variable ratios of concentrations of the two aromatic amino acids, the relative contribution of the two pathways to p-coumaric acid production may change. There are several factors that may potentially regulate the concentration of these two aromatic amino acids in the cytosol, such as a differential expression and activities of arogenate dehydratase and arogenate dehydrogenase or differential contributions of plastidic and cytosolic pathways from chorismate to Phe and Tyr (Eberhard et al, 1996a(Eberhard et al, , 1996b, as well as differential transport of the two amino acids across the plastid membranes. Also, the consumption of Phe and Tyr in protein synthesis as well as by other enzymes would have an impact on their concentrations.…”

Section: Potential Physiological Implicationsmentioning

confidence: 99%

Maize Phenylalanine Ammonia-Lyase Has Tyrosine Ammonia-Lyase Activity

et al. 1997

View full text Add to dashboard Cite

A full-length cDNA encoding phenylalanine ammonia-lyase (PAL) from Zea mays L. was isolated and the coding region was expressed in Escherichia coli as a C-terminal fusion to glutathione S-transferase. After purification by glutathione-Sepharose chromatography, the glutathione S-transferase moiety was cleaved off and the resulting PAL enzyme analyzed. In contrast to PAL from dicots, this maize PAL isozyme catalyzed the deamination of both i-phenylalanine (PAL activity) and i-tyrosine (tyrosine ammonialyase activity). These results provide unequivocal proof that PAL and tyrosine ammonia-lyase activities reside in the same polypeptide. In spite of large differences in the Michaelis constant and turnover number of the two activities, their catalytic efficiencies are very similar. Also, both activities have the same p H and temperature optima. These results imply that maize can produce p-coumaric acid from both phenylalanine and tyrosine.PAL (EC 4.3.1.5) catalyzes the elimination of ammonia from L-Phe to yield (E)-cinnamic acid ( Fig. 1) (Koukol and Com, 1961), the first step in the phenylpropanoid pathway (for reviews, see Hahlbrock and Scheel, 1989;Dixon and Paiva, 1995;Whetten and Sederoff, 1995;Campbell and Sederoff, 1996). PAL activity has been found in some fungi and in a11 higher plants analyzed but not in animals. Because of the central function of PAL at a branch point of metabolism, this enzyme is one of the best studied in plants; the same is true for its corresponding gene(s).In a11 plants analyzed, PAL has been shown to occur as a tetramer, and multiple forms have often been isolated (Bolwell et al., 1985). PAL multigene families, such as those in tomato (Lycopersicon esculentum; Lee et al., 1992), parsley (Petroselinum crispum; Appert et al., 1994), or Arabidopsis thaliana (Wanner et al., 1995), explain at least in part these different forms. The occurrence of heteromers is likely but has as yet not been proven. On the other hand, apparent charge isoforms of a poplar PAL were recovered from insect cell cultures producing the protein from a baculovirus expression vector containing the respective cDNA (McKegney et al., 1996).Results from severa1 studies (Neish, 1961; Young et al., 1966;Havir et al., 1971;Jangaard, 1974) indicated that the enzyme from monocots utilizes Tyr (TAL activity) in addition to Phe, whereas the enzyme from dicots utilizes only Phe efficiently. The four homotetrameric parsley PAL (Havir et al., 1971), indicating that PAL from maize also has TAL activity. However, the uncertainty remains that a protein with TAL activity copurifies with PAL activity. Referring to the heterologous expression of parsley PAL cDNAs (Schulz et al., 1989; Appert et al., 1994), Whetten and Sederoff (1995) stated: "The same experiment could be performed with maize cDNA to test for PAL and TAL activities in the same polypeptide." This is exactly the experiment we report here. Expression of a PAL-specific cDNA from maize in Escherichia coli provided the ultimate proof that PAL and TAL activities reside in ...

show abstract

Isolation of a cDNA from tomato coding for an unregulated, cytosolic chorismate mutase

Cited by 18 publications

References 23 publications

Identification of genes differentially expressed during ripening of banana

Identification of genes differentially expressed during ripening of banana

Genetic dissection of vitamin E biosynthesis in tomato

Maize Phenylalanine Ammonia-Lyase Has Tyrosine Ammonia-Lyase Activity

Contact Info

Product

Resources

About