Glycine and serine synthesis in non-photosynthetic tissues

Ireland, Robert J.; Hiltz, David

doi:10.1017/cbo9780511721809.009

Cited by 13 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These data indicate that glycine was metabolized by glycine decarboxylase (Ireland and Hilz 1995;, and that the serine produced was preferentially used for anabolic, and not catabolic reactions. The fraction of supplied 13 C lost as 13 CO 2 during the first week after additions was relatively low (1-14%; Fig.…”

Section: Discussionmentioning

confidence: 87%

Nitrogen acquisition from inorganic and organic sources by boreal forest plants in the field

et al. 2003

View full text Add to dashboard Cite

A wide range of recent studies have indicated that organic nitrogen may be of great importance to plant nitrogen (N) nutrition. Most of these studies have, however, been conducted in laboratory settings, excluding important factors for actual plant uptake, such as competition, mycorrhizal associations and soil interactions. In order to accurately evaluate the importance of different N compounds to plant N nutrition, field studies are crucial. In this study, we investigated short- as well as long-term plant nitrogen uptake by Deschampsia flexuosa, Picea abies and Vaccinium myrtillus from 15NO3-, 15NH4+ and (U-13C, 15N) arginine, glycine or peptides. Root N uptake was analysed after 6 h and 64 days following injections. Our results show that all three species, irrespective of their type of associated mycorrhiza (arbuscular, ecto- or ericoid, respectively) rapidly acquired similar amounts of N from the entire range of added N sources. After 64 days, P. abies and V. myrtillus had acquired similar amounts of N from all N sources, while for D. flexuosa, the uptake from all N sources except ammonium was significantly lower than that from nitrate. Furthermore, soil analyses indicate that glycine was rapidly decarboxylated after injections, while other organic compounds exhibited slower turnover. In all, these results suggest that a wide range of N compounds may be of importance for the N nutrition of these boreal forest plants, and that the type of mycorrhiza may be of great importance for N scavenging, but less important to the N uptake capacity of plants.

show abstract

Section: Discussionmentioning

confidence: 87%

Nitrogen acquisition from inorganic and organic sources by boreal forest plants in the field

et al. 2003

View full text Add to dashboard Cite

show abstract

“…Under conditions where¯ux through the photorespiratory pathway is diminished, glycine may be produced by alternative reactions (Fig. 5;Keys 1980;Kleczkowski and Givan 1988;Ireland and Hiltz 1995). There is some evidence that glycine synthase (i.e.…”

Section: Discussionmentioning

confidence: 99%

“…the glycine decarboxylase complex catalysing the reverse reaction) can catalyse the synthesis of glycine from CO 2 , NH 3 and methyl groups supplied by C 1 donors such as methylene tetrahydrofolate (CH 2 THF) (reviewed in Ireland and Hiltz 1995). However, the major route of glycine synthesis in darkened leaves and non-photosynthetic tissues is thought to be from serine produced from 3-phosphoglycerate (3-PGA) (Walton and Woolhouse 1986;Kleczkowski and Givan 1988;Ireland and Hiltz 1995). Serine may be formed from 3-PGA through the`phosphorylated' pathway via phosphoserine or the`non-phosphorylated' pathway via glycerate (Fig.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Light-dependent modulation of foliar glutathione synthesis and associated amino acid metabolism in poplar overexpressing γ-glutamylcysteine synthetase

Noctor¹,

Arisi

Jouanin

et al. 1997

Planta

View full text Add to dashboard Cite

Glutathione (GSH), c-glutamylcysteine (c-EC) and major free amino acids were measured in darkened and illuminated leaves from untransformed poplars (Populus tremula´P. alba) and poplars expressing Escherichia coli genes for c-glutamylcysteine synthetase (c-ECS; EC 3.2.3.3) and glutathione reductase (GR; EC 1.6.4.2). In poplars overexpressing c-ECS, foliar c-EC contents and GSH contents were markedly enhanced compared to poplars lacking the bacterial gene for the enzyme. However, the quantitative relationship between the foliar pools of c-EC and GSH in these transformants was markedly dependent on light. In the dark, GSH content was relatively low and c-EC content high, the latter being higher than the foliar GSH contents of untransformed poplars in all conditions. Hence, this transformation appears to elevate c-EC from the ranks of a trace metabolite to one of major quantitative importance. On illumination, however, c-EC content decreased fourfold whereas GSH content doubled. Glutathione was also higher in the light in untransformed poplars and in those overexpressing GR. In these plants, c-EC was negligible in the light but increased in the dark. Cysteine content was little aected by light in any of the poplar types. No light-dependent changes in the extractable activities of c-ECS, glutathione synthetase (EC 3.2.3.2) or GR were observed. In contrast, both the activation state and the maximum extractable activity of nitrate reductase (EC 1.6.6.1) were increased by illumination. In all poplar types, glutamate and aspartate were the major amino acids. The most marked light-induced increases in individual amino acids were observed in the glutamine, asparagine, serine and glycine pools. Illumination of leaves from poplars overexpressing c-ECS at elevated CO 2 or low O 2 largely abolished the inverse light-dependent changes in c-EC and GSH. Low O 2 did not aect foliar contents of cysteine or glutamate but prevented the light-induced increase in the glycine pool. It is concluded that light-dependent glycine formation through the photorespiratory pathway is required to support maximal rates of GSH synthesis, particularly under conditions where the capacity for c-EC synthesis is augmented.

show abstract

“…Serine is a key intermediate in a number of important metabolic pathways including the photorespiratory metabolism of glycolate to phosphoglycerate ( Walton & Woolhouse 1986). It is also important as a precursor biomolecule in the generation of glycine, tryptophane, cysteine and in the interconversion of homocysteine and methionine ( Ireland & Hiltz 1995;Walton & Woolhouse 1986). Besides these functions, serine is involved in the synthesis of phospholipids, porphyrins, purines and thymidine, and is the source of one‐carbon units.…”

Section: Introductionmentioning

confidence: 99%

Molecular characterization of plastidic phosphoserine aminotransferase in serine biosynthesis fromArabidopsis

Noji

Saito

et al. 1998

The Plant Journal

View full text Add to dashboard Cite

SummarySerine biosynthesis in plants proceeds by two pathways; a photorespiratory pathway which is associated with photorespiration and a pathway from phosphoglycerate. A cDNA encoding plastidic phosphoserine aminotransferase (PSAT) which catalyzes the formation of phosphoserine from phosphohydroxypyruvate has been isolated from Arabidopsis thaliana. Genomic DNA blot analysis indicated that this enzyme is most probably encoded by a single gene and is mapped on the lower arm of chromosome 4. The deduced protein contains an N-terminal extension exhibiting the general features of a plastidic transit peptide, which was confirmed by subcellular organelle localization using GFP (green flourescence protein). Northern analysis indicated preferential expression of PSAT in roots of light-grown plants, supporting the idea that the phosphorylated pathway may play an important role in supplying the serine requirement of plants in non-green tissues. In situ hybridization analysis of PSAT revealed that the gene is generally expressed in all types of cells with a significantly higher amount in the meristem tissue of root tips.

show abstract

Glycine and serine synthesis in non-photosynthetic tissues

Cited by 13 publications

References 0 publications

Nitrogen acquisition from inorganic and organic sources by boreal forest plants in the field

Nitrogen acquisition from inorganic and organic sources by boreal forest plants in the field

Light-dependent modulation of foliar glutathione synthesis and associated amino acid metabolism in poplar overexpressing γ-glutamylcysteine synthetase

Molecular characterization of plastidic phosphoserine aminotransferase in serine biosynthesis fromArabidopsis

Contact Info

Product

Resources

About