Cyclophilin 37 maintains electron transport via the cytochrome b6/f complex under high light in Arabidopsis.

Plants have evolved multiple mechanisms to cope with diverse types of light stress, particularly the regulation of the electron transport chain (ETC). Under high light (HL) conditions, the balance of electron flux in the ETC is disturbed, which leads to the overaccumulation of reactive oxygen species (ROS) and results in photodamage and photoinhibition. The cytochrome (Cyt) b6/f complex, which coordinates electron transfer between photosystems I and II (PSI and PSII), plays an essential role in regulating the ETC and initiating photoprotection.

The ability of P700 oxidation in photosystem I reflects chilling stress tolerance in cucumber.

Low temperature inhibits photosynthesis and negatively affects plant growth. Cucumber (Cucumis sativus L.) is a chilling-sensitive plant, and its greenhouse production requires considerable energy during the winter.

Coral symbionts evolved a functional polycistronic flavodiiron gene.

Photosynthesis in cyanobacteria, green algae, and basal land plants is protected against excess reducing pressure on the photosynthetic chain by flavodiiron proteins (FLV) that dissipate photosynthetic electrons by reducing O. In these organisms, the genes encoding FLV are always conserved in the form of a pair of two-type isozymes (FLVA and FLVB) that are believed to function in O photo-reduction as a heterodimer. While coral symbionts (dinoflagellates of the family Symbiodiniaceae) are the only algae to harbor FLV in photosynthetic red plastid lineage, only one gene is found in transcriptomes and its role and activity remain unknown.

Loss of mature D1 leads to compromised CP43 assembly in Arabidopsis thaliana.

Background: Photosystem II (PSII) is a highly conserved integral-membrane multi-subunit pigment-protein complex. The proteins, pigments, lipids, and ions in PSII need to be assembled precisely to ensure a proper PSII biogenesis. D1 is the main subunit of PSII core reaction center (RC), and is usually synthesized as a precursor D1.

Seedling Lethal 1 Interacting With Plastid-Encoded RNA Polymerase Complex Proteins Is Essential for Chloroplast Development.

Mitochondrial transcription termination factors (mTERFs) are highly conserved proteins in metazoans. Plants have many more mTERF proteins than animals. The functions and the underlying mechanisms of plants' mTERFs remain largely unknown.

Arabidopsis PsbP-Like Protein 1 Facilitates the Assembly of the Photosystem II Supercomplexes and Optimizes Plant Fitness under Fluctuating Light.

In green plants, photosystem II (PSII) forms multisubunit supercomplexes (SCs) containing a dimeric core and light-harvesting complexes (LHCs). In this study, we show that Arabidopsis thaliana PsbP-like protein 1 (PPL1) is involved in the assembly of the PSII SCs and is required for adaptation to changing light intensity. PPL1 is a homolog of PsbP protein that optimizes the water-oxidizing reaction of PSII in green plants and is required for the efficient repair of photodamaged PSII; however, its exact function has been unknown.

Arabidopsis CIPK14 positively regulates glucose response.

Calcium is a ubiquitous intracellular secondary messenger in plants. Calcineurin B-like proteins (CBLs), which contain four Ca(2+)-binding EF hand motifs, are Ca(2+) sensors and regulate a group of Ser/Thr protein kinases called CBL-interacting protein kinases (CIPKs). Although the CBL-CIPK network has been demonstrated to play crucial roles in plant development and responses to various environmental stresses in Arabidopsis, little is known about their function in glucose signaling.

C-terminal processing of reaction center protein D1 is essential for the function and assembly of photosystem II in Arabidopsis.

Photosystem II (PSII) reaction center protein D1 is synthesized as a precursor (pD1) with a short C-terminal extension. The pD1 is processed to mature D1 by carboxyl-terminal peptidase A to remove the C-terminal extension and form active protein. Here we report functional characterization of the Arabidopsis gene encoding D1 C-terminal processing enzyme (AtCtpA) in the chloroplast thylakoid lumen.

Mechanistic analysis of AKT1 regulation by the CBL-CIPK-PP2CA interactions.

Arabidopsis K+ transporter 1 (AKT1) participates in K+ uptake in roots, especially under low-K conditions. We recently identified a Ca²⁺ signaling pathway consisting of multiple calcineurin B-like calcium sensors (CBLs) and multiple target kinases (CBL-interacting protein kinases or CIPKs) that phosphorylate and activate AKT1, whereas a specific PP2C-type phosphatase inactivates CIPK-dependent AKT1 activity. In this study, we analyzed the interactions between PP2Cs and the CBL-CIPK pathway and found previously unsuspected mechanisms underlying the CBL-CIPK-PP2C signaling processes.