Figure 1 from Modification of Activity of the Thylakoid H+/K+ Antiporter KEA3 Disturbs ∆pH-Dependent Regulation of Photosynthesis1[OPEN] | Semantic Scholar (2024)

GH+ of the pgr5 mutant is restored to the wild-type level by introduction of flavodiiron protein and strong downregulation of the cytochrome b6f complex, counteracting proton leakage from the thylakoid membrane, and the gH+ parameter may be influenced by other factors not related to the H+ leakage through ATP synthase.

Evidence is provided that under conditions where cpATP synthase activity is low, a KEA3-dependent reduction of ΔpH benefits photosynthesis and growth, which is particularly important during transitions from high to low light.

The genetically reexamined the high-gH+ phenotype of the pgr5 mutant and concludes that the gH+ parameter may be influenced by other factors not related to the H+ leakage through ATP synthase.

It is revealed that the Arabidopsis KEA3 protein hom*o-dimerizes via its C-terminal domain has a regulatory function, which responds to light intensity transients, and a trade-off between long-term photoprotection and a short-term boost in carbon fixation rates is revealed.

It is discovered that the chlororespiratory reduction 2-1 (crr2-1) mutation, which abolished NDH-dependent CET, enhanced the kea3-1 mutant phenotypes in Arabidopsis, and two distinct modes of NDH action are proposed.

It is discovered that the chlororespiratory reduction 2-1 ( crr2-1 ) mutation, which abolished NDH- 55 dependent CET, enhanced the kea3-1 mutant phenotypes in Arabidopsis thaliana, and two distinct modes of NDH action are proposed.

Current knowledge of the network for pmf regulation is summarized, mainly based on genetic studies, to modify the extent of photosynthetic control without affecting the pmf size.

A computer model was proposed to investigate the transthylakoid electric phenomena in the chloroplast focusing on the interaction between cations and the negative charges close to the membrane surface and revealed the key role played by Donnan potential in regulating the energization of the thylakoids membrane.

Measurements of the electrochromic carotenoid absorbance shift (ECS) revealed that the light-dependent pH gradient across the thylakoid membrane was lower in the leaves of α-CA2-KO plants than in WT plants, and it is proposed that α- CA2 may be situated in the chloroplasts.

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The identification of a mutant allele of KEA3, disturbed proton gradient regulation (dpgr) based on its reduced non‐photochemical quenching (NPQ) in artificial (CO2‐free with low O2) air, and the findings suggest that fine regulation of K EA3 activity is necessary for optimizing photosynthesis in fluctuating light conditions are suggested.

It is shown that overexpression of the Arabidopsis thylakoid K+/H+ antiporter KEA3 accelerates the relaxation of photoprotective energy-dependent quenching after transitions from high to low light inArabidopsis and tobacco, which enhances PSII quantum efficiency in both organisms, supporting that in wild-type plants, residual light energyQuenching following a high toLow light transition represents a limitation to photosynthetic efficiency in fluctuating light.

Findings reveal an important Cl− channel required for ion transport and homeostasis across the thylakoid membrane in higher plants, which are essential for fine‐tuning photosynthesis under fluctuating environmental conditions.

The results underpin the importance of the thylakoid ion transport proteins potassium cation efflux antiporter KEA3 and voltage-dependent chloride channel VCCN1 and suggest that the activity of yet unknown K+ channel(s), but not TPK3, is critical for optimal photosynthesis in dynamic light environments.

A component of the thylakoid membrane, the two-pore potassium (K+) channel TPK3, which modulates the composition of the proton motive force through ion counterbalancing is described, which manages the pmf necessary to convert photochemical energy into physiological functions.

The effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux are seen, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field.

It is concluded that flavodiiron proteins can help to protect the photosystems in Arabidopsis under fluctuating light, even in the presence of CET.

It is proposed that AtCLCe functions in Cl− homeostasis after transition from light to dark, which affects chloroplast ultrastructure and regulation of photosynthetic electron transport.

Results indicate that Arabidopsis KEA1-KEA6 act as K+ transport systems, and support the interpretation that KEA3 promotes dissipation of ΔpH in the thylakoid membrane.

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