C4 photosynthesis: a unique elend of modified biochemistry, anatomy and ultrastructure

Hatch, M.D.

doi:10.1016/s0304-4173(87)80009-5

Cited by 867 publications

(904 citation statements)

References 138 publications

Supporting

Mentioning

872

Contrasting

Unclassified

Order By: Relevance

“…This enzyme is widely found in higher plants, algae and prokaryotes. In C4 plants, it catalyses the initial CO: fixation reaction in the mesophyll cells and the fixed CO2 is translocated in the form of dicarboxylic acid to the bundle sheath cells for decarboxylation with the released CO: entering Calvin cycle [1]. This mechanism raises CO: concentration in the bundle sheath cells and consequently minimises photorespiration during photosynthesis.…”

Section: Introductionmentioning

confidence: 99%

Site‐directed mutagenesis of Lys⁶⁰⁰ in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions

Gao¹,

Woo²

1995

FEBS Letters

View full text Add to dashboard Cite

Phosphoenolpyruvate carboxylases from various organisms contain two conserved lysine residues. In the C4 dicot Flaveria trinervia, one of these residues is Lys 6°°. Converting this Lys 6°° to Arg 6°° or Thr 6°° mainly increased the KI values and but had minimal effect on the Vma X. The Km for PEP, Mg 2+ increased by up to 3-fold in Arg 6°° and Thr 6°° but the Km (HCO]) increased 9-fold in Thr 6°°, suggesting that Lys 6°° might be associated with bicarbonate-binding. This lysine was not obligatory for enzyme activity although the wild-type protein showed higher activity at physiological pH and was less inhibited by malate than the two mutants.Key words: Phosphoenolpyruvate carboxylase; Lysine; Substrate-binding site; Flaveria trinervia binding sites are associated with some of these conserved residues and, since the substrates are anions at neutral pH, it is likely that positively charged residues are involved in the binding sites. Chemical modifications indicate that 2 histidine [6], 2 arginine [7] and 4 lysine [8-10] residues per tetramer are essential for the enzyme function. Modifications of these residues, which may form a substrate (PEP) domain [11], result in enzyme inactivation. In vitro mutagenesis has identified two conserved histidine residues as the PEP-binding sites [12,13]. In this study, we have changed Lys 6°~ in E trinervia, a site previously thought to be involved in PEP-binding [14], to arginine or threonine by techniques of site-directed mutagenesis, and compared their kinetic and regulatory properties with the wildtype enzyme.

show abstract

Section: Introductionmentioning

confidence: 99%

Site‐directed mutagenesis of Lys⁶⁰⁰ in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions

Gao¹,

Woo²

1995

FEBS Letters

View full text Add to dashboard Cite

show abstract

“…It is invariably localized to the chloroplasts with the pyruvate phosphate dikinase (also known as pyruvate orthophosphate dikinase) as the central enzyme [4,[21][22][23]. It produces PEP, pyrophosphate (PP) and adenosine monophosphosphate (AMP) from pyruvate, phosphate and ATP.…”

Section: Modules Of the C 4 Cyclementioning

confidence: 99%

“…The global perspective, which tests all genes at the same time, identifies both changes that are expected based on previously published data (i.e. enzyme assays or Western Blots; summarized in [4]) and changes that are not anticipated. Unlike the targeted approaches that existed before, RNA-seq is not limited to measuring abundance of known or expected transcripts.…”

Section: Introductionmentioning

confidence: 99%

“…The metabolic aspect of the trait can be deconstructed in the C 4 cycle itself consisting of carboxylation, transfer acid generation, decarboxylation and regeneration modules and their integration in the underlying leaf metabolism which presumably resembles that of non-C 4 plants ( Figure 1, Table 1). Originally, three types of C 4 cycles were recognized, the NADP-malic enzyme (NADP-ME), the NADmalic enzyme (NAD-ME) and the phosphoenolpyruvate (PEP) carboxykinase (PEP-CK) type [4] and they were named according to the presence of decarboxylation enzymes [4]. This simplistic view was theoretically questioned [11] at the same time as multiple lines of evidence showed a more complex cycle than previously envisioned [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

“…In the majority of plants, the carboxylation and decarboxylation modules are separated into different cell types, the mesophyll and bundle sheath, but in a variety of Chenopdiaceae and Hydrilla they also occur in the same cell [15]. Many enzymes involved in the C 4 cycle reside in organelles rather than in the cytosol [4]. Their localization necessitates the presence of transport proteins which connect the reactions of the C 4 cycle to the cytosol [16].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Understanding metabolite transport and metabolism in C4 plants through RNA-seq

Schlüter

Denton

Bräutigam

2016

Current Opinion in Plant Biology

View full text Add to dashboard Cite

RNA-seq, the measurement of steady-state RNA levels by next generation sequencing, has enabled quantitative transcriptome analyses of complex traits in many species without requiring the parallel sequencing of their genomes. The complex trait of C 4 photosynthesis, which increases photosynthetic efficiency via a biochemical pump that concentrates CO 2 around RubisCO, has evolved convergently multiple times. Due to these interesting properties, C 4 photosynthesis has been analyzed in a series of comparative RNA-seq projects. These projects compared both species with and without the C 4 trait and different tissues or organs within a C 4 plant. The RNA-seq studies were evaluated by comparing to earlier single gene studies. The studies confirmed the marked changes expected for C 4 signature genes, but also revealed numerous new players in C 4 metabolism showing that the C 4 cycle is more complex than previously thought, and suggesting modes of integration into the underlying C 3 metabolism.

show abstract

Flow cytometry of mesophyll and bundle sheath chloroplast thylakoids of maize (Zea mays L.)

Pfündel

Meister

1996

Cytometry

View full text Add to dashboard Cite

Chlorophyll fluorescence at short and long wave‐lengths was used to sort thylakoid membranes of maize, a plant with the C4 dicarboxylic acid pathway of photosynthesis, in a flow cytometer. The method yielded two distinct particle populations that were identified as mesophyll and bundle sheath thylakoids by low‐temperature fluorescence spectroscopy and by the pigment ratio of chlorophyll a/b. Mesophyll and bundle sheath thylakoids were essentially pure after sorting by flow cytometry. Fluorescence data and chlorophyll a/b pigment ratios of thylakoids separated by flow cytometry were compared with earlier data of preparations obtained by conventional isolation procedures. Our results indicate that impure mesophyll and bundle sheath membranes were used in most previous investigations. We were unable to detect the major light‐harvesting complex of PS II (LHC II) in our pure bundle sheath thylakoids using fluorescence excitation spectroscopy. Therefore, we believe that the previously reported presence of LHC II in bundle sheath chloroplasts of maize can be attributed to mesophyll contamination. © 1996 Wiley‐Liss, Inc.

show abstract

C4 photosynthesis: a unique elend of modified biochemistry, anatomy and ultrastructure

Cited by 867 publications

References 138 publications

Site‐directed mutagenesis of Lys⁶⁰⁰ in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions

Site‐directed mutagenesis of Lys⁶⁰⁰ in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions

Understanding metabolite transport and metabolism in C4 plants through RNA-seq

Flow cytometry of mesophyll and bundle sheath chloroplast thylakoids of maize (Zea mays L.)

Contact Info

Product

Resources

About

C4 photosynthesis: a unique elend of modified biochemistry, anatomy and ultrastructure

Cited by 867 publications

References 138 publications

Site‐directed mutagenesis of Lys600 in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions

Site‐directed mutagenesis of Lys600 in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions

Understanding metabolite transport and metabolism in C4 plants through RNA-seq

Flow cytometry of mesophyll and bundle sheath chloroplast thylakoids of maize (Zea mays L.)

Contact Info

Product

Resources

About

Site‐directed mutagenesis of Lys⁶⁰⁰ in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions

Site‐directed mutagenesis of Lys⁶⁰⁰ in phosphoenolpyruvate carboxylase of Flaveria trinervia: its roles in catalytic and regulatory functions