C4 photosynthesis is present in approximately 7,500 species classified into 19 families, including monocots and eudicots. In the majority of documented cases, a two-celled CO2-concentrating system that uses a metabolic cycle of four-carbon compounds is employed. C4 photosynthesis repeatedly evolved from C3 photosynthesis, possibly driven by the survival advantages it bestows in the hot, often dry, and nutrient-poor soils of the tropics and subtropics. The development of the C4 metabolic cycle greatly increased the ATP demand in chloroplasts during the evolution of malic enzyme-type C4 photosynthesis, and the additional ATP required for C4 metabolism may be produced by the cyclic electron transport around PSI. Recent studies have revealed the nature of cyclic electron transport and the elevation of its components during C4 evolution. In this review, we discuss the energy requirements of C3 and C4 photosynthesis, the current model of cyclic electron transport around PSI and how cyclic electron transport is promoted during C4 evolution using studies on the genus Flaveria, which contains a number of closely related C3, C4 and C3-C4 intermediate species.
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http://dx.doi.org/10.1093/pcp/pcw012 | DOI Listing |
Heliyon
January 2025
Environmental Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
In this study, a Cu@Ag core-shell was synthesized using a co-precipitation method. To create a new electrochemical sensor, a Cu@Ag core-shell with conductive polymers such as polyalizarin yellow R (PA) and Nafion (Nf) was immobilized on the surface of a glassy carbon electrode (Cu@Ag-Nf/PA/GCE). X-ray diffraction analysis (XRD), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR) techniques were employed to characterize the Cu@Ag-Nf/PA/GCE.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
An electrochemical method for the oxidative dearomatization of electron-deficient phenols by employing tetrabutylammonium bromide as a mediator under aqueous biphasic conditions is reported. This approach represents a safer alternative to the use of stoichiometric chemical oxidants and enables oxidative dearomative spirolactonization and spiroetherification reactions. Compared to previous approaches based on direct electrolysis, this strategy expands the substrate scope to electron-deficient phenols.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Exploiting novel noncovalent interactions for catalysis design represents a fascinating direction. For the flexible and relatively weak anion-π interactions, manipulation of two or more π-acidic surfaces for cooperative activation is highly desirable. Here, we demonstrate the strategy of cooperative anion-π catalysis based on chiral molecular cages with V-shaped electron-deficient cavities for synergic binding and activation of dicarbonyl electrophiles toward highly enantioselective desymmetrization transformation.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Institute of Hybrid Materials, National Center of International Research for Hybrid Materials Technology, National Base of International Science & Technology Cooperation, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. Electronic address:
Self-supported hardwood kraft lignin (HKL)/graphene-based carbon fibrous aerogel (L/GCA) presents a fascinating prospect as the electrode of supercapacitor due to its impress rate capacity and cyclic stability. However, the hydrophobicity nature of L/GCA hampers the ion transfer between the electrode and electrolyte, thereby limiting its electrochemical performance. To address this, we enhanced the electrochemical performance of L/GCA through boron doping based on the improvement of hydrophilicity and the re-arrangement of electron density.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
The delocalization length of charge carriers in organic semiconductors influences their mobility and is an important factor in the design of functional materials. Here, we have studied the radical anions of a series of linear and cyclic butadiyne-linked porphyrin oligomers using CW-EPR, H Mims ENDOR and NIR/MIR spectroelectrochemistry together with DFT calculations and multiscale molecular modeling. Low-temperature hyperfine EPR spectroscopy and optical data show that polarons are delocalized nonuniformly over about four porphyrins with most of the spin density on just two units even in the cyclic structures, in which all porphyrin sites are identical.
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