Enzymatic activity, gene expression and posttranslational modifications of photosynthetic and non-photosynthetic phosphoenolpyruvate carboxylase in ammonium-stressed sorghum plants

Arias-Baldrich, Cirenia; Osa, Clara de la; Bosch, Nadja; Ruíz-Ballesta, Isabel; Monreal, J. A.; García‐Mauriño, Sofía

doi:10.1016/j.jplph.2017.03.020

Cited by 26 publications

(26 citation statements)

References 55 publications

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“…Indeed, low malate and PEP contents indicate a higher consumption under ammonium nutrition; therefore, confirming the prioritization of the pathway generating TCA intermediates, mainly OAA and 2-OG. The role of PEPC, ME and ICDH in root response to ammonium nutrition has been highlighted in different species including pea and sorghum (Ariz et al 2013; Arias-Baldrich et al 2017). Moreover, the relevance of PEPC agrees with a report where Arabidopsis ppc1/ppc2 double mutant was impaired in ammonium assimilation (Shi et al 2015).…”

Section: Discussionmentioning

confidence: 99%

Providing carbon skeletons to sustain amide synthesis in roots underlines the suitability of Brachypodium distachyon for the study of ammonium stress in cereals

Peña

González‐Moro

2019

AoB PLANTS

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Plants mainly acquire N from the soil in the form of nitrate (NO3−) or ammonium (NH4+). Ammonium-based nutrition is gaining interest because it helps to avoid the environmental pollution associated with nitrate fertilization. However, in general, plants prefer NO3− and indeed, when growing only with NH4+ they can encounter so-called ammonium stress. Since Brachypodium distachyon is a useful model species for the study of monocot physiology and genetics, we chose it to characterize performance under ammonium nutrition. Brachypodium distachyon Bd21 plants were grown hydroponically in 1 or 2.5 mM NO3− or NH4+. Nitrogen and carbon metabolism associated with NH4+ assimilation was evaluated in terms of tissue contents of NO3−, NH4+, K, Mg, Ca, amino acids and organic acids together with tricarboxylic acid (TCA) cycle and NH4+-assimilating enzyme activities and RNA transcript levels. The roots behaved as a physiological barrier preventing NH4+ translocation to aerial parts, as indicated by a sizeable accumulation of NH4+, Asn and Gln in the roots. A continuing high NH4+ assimilation rate was made possible by a tuning of the TCA cycle and its associated anaplerotic pathways to match 2-oxoglutarate and oxaloacetate demand for Gln and Asn synthesis. These results show B. distachyon to be a highly suitable tool for the study of the physiological, molecular and genetic basis of ammonium nutrition in cereals.

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Section: Discussionmentioning

confidence: 99%

Providing carbon skeletons to sustain amide synthesis in roots underlines the suitability of Brachypodium distachyon for the study of ammonium stress in cereals

Peña

González‐Moro

2019

AoB PLANTS

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“…Moreover, in a study of PEPC in ammonium-stressed sorghum, the expression of the C 3 -type PPC5 and the bacterial-type PPC6 was not detected in leaves and in roots but NH4 + has been shown to increase the phosphorylation state of PEPC and PEPC-kinase activity in the leaves both in the presence and absence of light [50]. NH4 + also increased the amount of monoubiquitinated PEPC in sorghum roots; hence, in such a case, although the roles of phosphorylation and monoubiquitination seem to be opposite in manner, both PTM's co-exist in leaves and in roots, respectively.…”

Section: Posttranslational Modifications (Ptms): Phosphorylation and Monoubiquitination Of Pepcsmentioning

confidence: 98%

“…NH4 + also increased the amount of monoubiquitinated PEPC in sorghum roots; hence, in such a case, although the roles of phosphorylation and monoubiquitination seem to be opposite in manner, both PTM's co-exist in leaves and in roots, respectively. An increase in phosphorylation was a consequence of favorable PPCK1 expression in leaves, while PEPC activity in roots augmented due to the increase in PPC3 expression thus increasing the capacity of sorghum to cope with the ammonium stress [50]. Recent studies of Gandullo and colleagues [51] on sorghum leaves found that phosphorylated PEPC is less sensitive to proteolysis than its dephosphorylated form in vivo and in vitro.…”

Section: Posttranslational Modifications (Ptms): Phosphorylation and Monoubiquitination Of Pepcsmentioning

confidence: 99%

Differential Expression, Tissue-Specific Distribution, and Posttranslational Controls of Phosphoenolpyruvate Carboxylase

Caburatan

Park

2021

Plants

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Phosphoenolpyruvate carboxylase (PEPC) is a ubiquitous cytosolic enzyme, which is crucial for plant carbon metabolism. PEPC participates in photosynthesis by catalyzing the initial fixation of atmospheric CO2 and is abundant in both C4 and crassulacean acid metabolism leaves. PEPC is differentially expressed at different stages of plant development, mostly in leaves, but also in developing seeds. PEPC is known to show tissue-specific distribution in leaves and in other plant organs, such as roots, stems, and flowers. Plant PEPC undergoes reversible phosphorylation and monoubiquitination, which are posttranslational modifications playing important roles in regulatory processes and in protein localization. Phosphorylation activates the PEPC enzyme, making it more sensitive to glucose-6-phosphate and less sensitive to malate or aspartate. PEPC phosphorylation is known to be diurnally regulated and delicately changed in response to various environmental stimuli, in addition to light. PEPCs belong to a small gene family encoding several plant-type and distantly related bacterial-type PEPCs. This paper provides a minireview of the general information on PEPCs in both C4 and C3 plants.

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“…Phosphorylation involves an N-terminal regulatory serine (Ser8 in C 4 -PEPC from sorghum), and this regulatory post-translational modification (PTM) interacts with metabolite effectors to decrease its sensitivity to feedback inhibition by L-malate and increase its affinity for the allosteric activator Glc-6P and its Vmax (Echevarría and Vidal 2003;Nimmo 2003). PEPC is also subjected to different PTMs, such as monoubiquitination (Uhrig et al 2008;Ruíz-Ballesta et al 2014, 2016, nitric oxide-related PTMs (S-nitrosylation, Tyr-nitration), and PTMs associated with oxidative stress (carbonylation; Arias-Baldrich et al 2017;Baena et al 2017). Monoubiquitination of Arabidopsis C 3 -PEPC is selectively degraded by autophagy (Baena et al 2021).…”

Section: Introductionmentioning

confidence: 99%

A conserved C-terminal peptide of sorghum phosphoenolpyruvate carboxylase promotes its proteolysis, which is prevented by Glc-6P or the phosphorylation state of the enzyme

Gandullo

Álvarez

Feria

et al. 2021

Planta

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Main conclusion A synthetic peptide from the C-terminal end of C4-phosphoenolpyruvate carboxylase is implicated in the proteolysis of the enzyme, and Glc-6P or phosphorylation of the enzyme modulate this effect. Abstract Phosphoenolpyruvate carboxylase (PEPC) is a cytosolic, homotetrameric enzyme that performs a variety of functions in plants. Among them, it is primarily responsible for CO2 fixation in the C4 photosynthesis pathway (C4-PEPC). Here we show that proteolysis of C4-PEPC by cathepsin proteases present in a semi-purified PEPC fraction was enhanced by the presence of a synthetic peptide containing the last 19 amino acids from the C-terminal end of the PEPC subunit (pC19). Threonine (Thr)944 and Thr948 in the peptide are important requirements for the pC19 effect. C4-PEPC proteolysis in the presence of pC19 was prevented by the PEPC allosteric effector glucose 6-phosphate (Glc-6P) and by phosphorylation of the enzyme. The role of these elements in the regulation of PEPC proteolysis is discussed in relation to the physiological context.

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Enzymatic activity, gene expression and posttranslational modifications of photosynthetic and non-photosynthetic phosphoenolpyruvate carboxylase in ammonium-stressed sorghum plants

Cited by 26 publications

References 55 publications

Providing carbon skeletons to sustain amide synthesis in roots underlines the suitability of Brachypodium distachyon for the study of ammonium stress in cereals

Providing carbon skeletons to sustain amide synthesis in roots underlines the suitability of Brachypodium distachyon for the study of ammonium stress in cereals

Differential Expression, Tissue-Specific Distribution, and Posttranslational Controls of Phosphoenolpyruvate Carboxylase

A conserved C-terminal peptide of sorghum phosphoenolpyruvate carboxylase promotes its proteolysis, which is prevented by Glc-6P or the phosphorylation state of the enzyme

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