The regulation and control of photorespiration

Leegood, Richard C.; Lea, Peter J.; Adcock, Michael D.; Häusler, Rainer E.

doi:10.1093/jxb/46.special_issue.1397

Cited by 228 publications

(137 citation statements)

References 136 publications

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“…However, a direct support for this hypothesis in the context of our results is currently lacking. That said, a relationship between senescence and photorespiration has been suggested in several studies of photorespirationdeficient mutants (Somerville, 1986;Blackwell et al, 1988;Leegood et al, 1995). However, differences in light conditions (long days in the whole-plant experiment and short days in the single-leaf experiment) for plant growth are another possible explanation for the differences in Gly and Ser levels observed here.…”

Section: Metabolism Of Amino Acids and Mineral Nutrients During Develsupporting

confidence: 51%

Comprehensive Dissection of Spatiotemporal Metabolic Shifts in Primary, Secondary, and Lipid Metabolism during Developmental Senescence in Arabidopsis

et al. 2013

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Developmental senescence is a coordinated physiological process in plants and is critical for nutrient redistribution from senescing leaves to newly formed sink organs, including young leaves and developing seeds. Progress has been made concerning the genes involved and the regulatory networks controlling senescence. The resulting complex metabolome changes during senescence have not been investigated in detail yet. Therefore, we conducted a comprehensive profiling of metabolites, including pigments, lipids, sugars, amino acids, organic acids, nutrient ions, and secondary metabolites, and determined approximately 260 metabolites at distinct stages in leaves and siliques during senescence in Arabidopsis (Arabidopsis thaliana). This provided an extensive catalog of metabolites and their spatiotemporal cobehavior with progressing senescence. Comparison with silique data provides clues to source-sink relations. Furthermore, we analyzed the metabolite distribution within single leaves along the basipetal sink-source transition trajectory during senescence. Ceramides, lysolipids, aromatic amino acids, branched chain amino acids, and stressinduced amino acids accumulated, and an imbalance of asparagine/aspartate, glutamate/glutamine, and nutrient ions in the tip region of leaves was detected. Furthermore, the spatiotemporal distribution of tricarboxylic acid cycle intermediates was already changed in the presenescent leaves, and glucosinolates, raffinose, and galactinol accumulated in the base region of leaves with preceding senescence. These results are discussed in the context of current models of the metabolic shifts occurring during developmental and environmentally induced senescence. As senescence processes are correlated to crop yield, the metabolome data and the approach provided here can serve as a blueprint for the analysis of traits and conditions linking crop yield and senescence.

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Section: Metabolism Of Amino Acids and Mineral Nutrients During Develsupporting

confidence: 51%

Comprehensive Dissection of Spatiotemporal Metabolic Shifts in Primary, Secondary, and Lipid Metabolism during Developmental Senescence in Arabidopsis

et al. 2013

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“…This young leaf was used in both NH 4 1 and NL plants because older leaves were not able to exude. In Fd-GOGAT antisense plants, photorespiration and thus ammonium production in the mitochondria has been shown to be higher in young photosynthetically active leaves (Leegood et al, 1995). The ammonium concentration of the phloem sap was 16 times higher in NH 4 1 plants compared to NL plants (Table I).…”

Section: Relative Ammonium Concentration In the Phloem Sapmentioning

confidence: 93%

Glutamate Dehydrogenase of Tobacco Is Mainly Induced in the Cytosol of Phloem Companion Cells When Ammonia Is Provided Either Externally or Released during Photorespiration

et al. 2004

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Glutamate (Glu) dehydrogenase (GDH) catalyses the reversible amination of 2-oxoglutarate for the synthesis of Glu using ammonium as a substrate. This enzyme preferentially occurs in the mitochondria of companion cells of a number of plant species grown on nitrate as the sole nitrogen source. For a better understanding of the controversial role of GDH either in ammonium assimilation or in the supply of 2-oxoglutarate (F. Dubois, T. Tercé-Laforgue, M.B. Gonzalez-Moro, M.B. Estavillo, R. Sangwan, A. Gallais, B. Hirel [2003] Plant Physiol Biochem 41: 565-576), we studied the localization of GDH in untransformed tobacco (Nicotiana tabacum) plants grown either on low nitrate or on ammonium and in ferredoxin-dependent Glu synthase antisense plants. Production of GDH and its activity were strongly induced when plants were grown on ammonium as the sole nitrogen source. The induction mainly occurred in highly vascularized organs such as stems and midribs and was likely to be due to accumulation of phloem-translocated ammonium in the sap. GDH induction occurred when ammonia was applied externally to untransformed control plants or resulted from photorespiratory activity in transgenic plants down-regulated for ferredoxin-dependent Glu synthase. GDH was increased in the mitochondria and appeared in the cytosol of companion cells. Taken together, our results suggest that the enzyme plays a dual role in companion cells, either in the mitochondria when mineral nitrogen availability is low or in the cytosol when ammonium concentration increases above a certain threshold.Ammonium is the ultimate form of inorganic nitrogen available to the plant. It can originate from a wide variety of metabolic processes such as nitrate reduction, photorespiration, phenylpropanoid metabolism, utilization of nitrogen transport compounds, amino acid catabolism, symbiotic nitrogen fixation (Hirel and Lea, 2001), and insect digestion in carnivorous plants (Schulze et al., 1997). It is then incorporated into an organic molecule, 2-oxoglutarate, by the combined action of the enzymes Gln synthetase (GS) and Glu synthase (Gln-2-oxoglutarate aminotransferase; GOGAT) to allow the synthesis of Gln and Glu. Both amino acids are further used as amino group donors for the synthesis of virtually all the nitrogencontaining molecules including the other amino acids needed for protein synthesis and nucleotides used as basic molecules for RNA and DNA synthesis (Hirel and Lea, 2001). The GS/GOGAT cycle is the major mechanism of ammonium assimilation in higher plants regardless of the various sources of ammonium listed above. However, it has often been argued that other enzymes have the capacity to assimilate ammonium, leading to the hypothesis that alternative pathways might operate under particular physiological conditions when the GS/GOGAT pathway may not be able to fulfill its function (Harrison et al., 2003).One of these alternative pathways is the reaction catalyzed by the mitochondrial NAD(H)-dependent Glu dehydrogenase (GDH; EC 1.4.1.2), which possesses the ...

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“…On the one hand, levels of glycolate, Ser, and particularly HP oscillated with a rather low amplitude (up to 4-fold), which is probably due to efficient metabolite channeling within the peroxisomes (Heupel et al, 1991). In addition, the enzymes that are involved in the turnover of these metabolites (GOX, Glu:glyoxylate aminotransferase, Ser: glyoxylate aminotransferase, HPR1, catalase, malate dehydrogenase) are highly abundant in peroxisomes (Reumann et al, 2007) and characterized by high affinities toward their substrates (for review, see Leegood et al, 1995). These features counteract the massive accumulation of the respective enzyme substrates.…”

Section: The Onset Of Light Coordinately Increases Metabolites Protementioning

confidence: 99%

Serine Acts as a Metabolic Signal for the Transcriptional Control of Photorespiration-Related Genes in Arabidopsis

et al. 2013

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Photosynthetic carbon assimilation including photorespiration is dynamically regulated during the day/night cycle. This includes transcriptional regulation, such as the light induction of corresponding genes, but little is known about the contribution of photorespiratory metabolites to the regulation of gene expression. Here, we examined diurnal changes in the levels of photorespiratory metabolites, of enzymes of the photorespiratory carbon cycle, and of corresponding transcripts in wild-type plants of Arabidopsis (Arabidopsis thaliana) and in a mutant with altered photorespiratory flux due to the absence of the peroxisomal enzyme Hydroxypyruvate Reductase1 (HPR1). Metabolomics of the wild type showed that the relative amounts of most metabolites involved in photorespiration increased after the onset of light, exhibited maxima at the end of the day, and decreased during the night. In accordance with those findings, both the amounts of messenger RNAs encoding photorespiratory enzymes and the respective protein contents showed a comparable accumulation pattern. Deletion of HPR1 did not significantly alter most of the metabolite patterns relative to wild-type plants; only serine accumulated to a constitutively elevated amount in this mutant. In contrast, the hpr1 mutation resulted in considerable deregulation of the transcription of photorespiration-related genes. This transcriptional deregulation could also be induced by the external application of L-serine but not glycine to the Arabidopsis wild type, suggesting that serine acts as a metabolic signal for the transcriptional regulation of photorespiration, particularly in the glycine-to-serine interconversion reactions.

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The regulation and control of photorespiration

Cited by 228 publications

References 136 publications

Comprehensive Dissection of Spatiotemporal Metabolic Shifts in Primary, Secondary, and Lipid Metabolism during Developmental Senescence in Arabidopsis

Comprehensive Dissection of Spatiotemporal Metabolic Shifts in Primary, Secondary, and Lipid Metabolism during Developmental Senescence in Arabidopsis

Glutamate Dehydrogenase of Tobacco Is Mainly Induced in the Cytosol of Phloem Companion Cells When Ammonia Is Provided Either Externally or Released during Photorespiration

Serine Acts as a Metabolic Signal for the Transcriptional Control of Photorespiration-Related Genes in Arabidopsis

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