Assessment of the requirement for aquaporins in the thylakoid membrane of plant chloroplasts to sustain photosynthetic water oxidation

Beebo, Azeez; Mathai, John; Schoefs, Benoı̂t; Spetea, Cornelia

doi:10.1016/j.febslet.2013.05.046

Cited by 36 publications

(25 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding suggests that other ions or chemical compounds enter the thylakoid lumen instead of Cl − . Furthermore, several aquaporins were postulated to be present in the thylakoid membrane, which may be required for rapid regulation of lumen volume following ion flux activity during photosynthesis (Beebo et al ). The finding that the lumen was enlarged in the atbest mutant suggests that, in coordination with other channels and transporters, AtBest is critical for the regulation of lumen volume.…”

Section: Discussionmentioning

confidence: 99%

A bestrophin‐like protein modulates the proton motive force across the thylakoid membrane in Arabidopsis

Duan

Kong

Zhang

et al. 2016

JIPB

View full text Add to dashboard Cite

During photosynthesis, photosynthetic electron transport generates a proton motive force (pmf) across the thylakoid membrane, which is used for ATP biosynthesis via ATP synthase in the chloroplast. The pmf is composed of an electric potential (ΔΨ) and an osmotic component (ΔpH). Partitioning between these components in chloroplasts is strictly regulated in response to fluctuating environments. However, our knowledge of the molecular mechanisms that regulate pmf partitioning is limited. Here, we report a bestrophin‐like protein (AtBest), which is critical for pmf partitioning. While the ΔpH component was slightly reduced in atbest, the ΔΨ component was much greater in this mutant than in the wild type, resulting in less efficient activation of nonphotochemical quenching (NPQ) upon both illumination and a shift from low light to high light. Although no visible phenotype was observed in the atbest mutant in the greenhouse, this mutant exhibited stronger photoinhibition than the wild type when grown in the field. AtBest belongs to the bestrophin family proteins, which are believed to function as chloride (Cl−) channels. Thus, our findings reveal an important Cl− channel required for ion transport and homeostasis across the thylakoid membrane in higher plants. These processes are essential for fine‐tuning photosynthesis under fluctuating environmental conditions.

show abstract

Section: Discussionmentioning

confidence: 99%

A bestrophin‐like protein modulates the proton motive force across the thylakoid membrane in Arabidopsis

Duan

Kong

Zhang

et al. 2016

JIPB

View full text Add to dashboard Cite

show abstract

“…The overexpression of tonoplast-targeted fluorescent proteins by the 35S promoter, and the weak dimerization of tonoplast-targeted GFP, have been suggested to produce artificial structures . Additionally, large-scale proteomics analysis suggested the localization of δTIP in the chloroplast envelope or thylakoid (Beebo et al, 2013). To rule out the possibility that tonoplast structures engulfing swollen ) leaves or leaves exposed to a 2-h HL treatment (2,000 µmol m −2 s −1 at 10°C) in wild-type (WT), Pro35S:VIPP1-GFP, or Pro35S:VIPP1Δc-GFP plants within the ProRBCS:RBCS-mRFP background.…”

Section: The Elimination Of Swollen Chloroplasts Is An Atg-dependent mentioning

confidence: 99%

Selective Elimination of Membrane-Damaged Chloroplasts via Microautophagy

et al. 2018

View full text Add to dashboard Cite

Plant chloroplasts constantly accumulate damage caused by visible wavelengths of light during photosynthesis. Our previous study revealed that entire photodamaged chloroplasts are subjected to vacuolar digestion through an autophagy process termed chlorophagy; however, how this process is induced and executed remained poorly understood. In this study, we monitored intracellular induction of chlorophagy in Arabidopsis () leaves and found that mesophyll cells damaged by high visible light displayed abnormal chloroplasts with a swollen shape and 2.5 times the volume of normal chloroplasts. In wild-type plants, the activation of chlorophagy decreased the number of swollen chloroplasts. In the autophagy-deficient mutants, the swollen chloroplasts persisted, and dysfunctional chloroplasts that had lost chlorophyll fluorescence accumulated in the cytoplasm. Chloroplast swelling and subsequent induction of chlorophagy were suppressed by the application of exogenous mannitol to increase the osmotic pressure outside chloroplasts or by overexpression of VESICLE INDUCING PROTEIN IN PLASTID1, which maintains chloroplast envelope integrity. Microscopic observations of autophagy-related membranes showed that swollen chloroplasts were partly surrounded by autophagosomal structures and were engulfed directly by the tonoplast, as in microautophagy. Our results indicate that an elevation in osmotic potential inside the chloroplast due to high visible light-derived envelope damage results in chloroplast swelling and serves as an induction factor for chlorophagy, and this process mobilizes entire chloroplasts via tonoplast-mediated sequestering to avoid the cytosolic accumulation of dysfunctional chloroplasts.

show abstract

“…In chloroplasts, water must be supplied to the thylakoid lumen to sustain photosynthetic water oxidation and for regulatory volume changes of the lumen in the light [60]. The apparent basal water permeability of the spinach thylakoid membrane was found to be low but sufficient to sustain water oxidation.…”

Section: The Photosynthetic Machinery Requires Thylakoid Channels Andmentioning

confidence: 99%

Function and evolution of channels and transporters in photosynthetic membranes

Pfeil

Schoefs

Spetea

2013

Cell. Mol. Life Sci.

Self Cite

View full text Add to dashboard Cite

Chloroplasts from land plants and algae originated from an endosymbiotic event, most likely involving an ancestral photoautotrophic prokaryote related to cyanobacteria. Both chloroplasts and cyanobacteria have thylakoid membranes, harboring pigment-protein complexes that perform the light-dependent reactions of oxygenic photosynthesis. The composition, function and regulation of these complexes have thus far been the major topics in thylakoid membrane research. For many decades, we have also accumulated biochemical and electrophysiological evidence for the existence of solute transthylakoid transport activities that affect photosynthesis. However, research dedicated to molecular identification of the responsible proteins has only recently emerged with the explosion of genomic information. Here we review the current knowledge about channels and transporters from the thylakoid membrane of Arabidopsis thaliana and of the cyanobacterium Synechocystis sp. PCC 6803. No homologues of these proteins have been characterized in algae, although similar sequences could be recognized in many of the available sequenced genomes. Based on phylogenetic analyses, we hypothesize a host origin for most of the so far identified Arabidopsis thylakoid channels and transporters. Additionally, the shift from a non-thylakoid to a thylakoid location appears to have occurred at different times for different transport proteins. We propose that closer control of and provision for the thylakoid by products of the host genome has been an ongoing process, rather than a one-step event. Some of the proteins recruited to serve in the thylakoid may have been the result of the increased specialization of its pigment-protein composition and organization in green plants.Electronic supplementary materialThe online version of this article (doi:10.1007/s00018-013-1412-3) contains supplementary material, which is available to authorized users.

show abstract

Assessment of the requirement for aquaporins in the thylakoid membrane of plant chloroplasts to sustain photosynthetic water oxidation

Cited by 36 publications

References 73 publications

A bestrophin‐like protein modulates the proton motive force across the thylakoid membrane in Arabidopsis

A bestrophin‐like protein modulates the proton motive force across the thylakoid membrane in Arabidopsis

Selective Elimination of Membrane-Damaged Chloroplasts via Microautophagy

Function and evolution of channels and transporters in photosynthetic membranes

Contact Info

Product

Resources

About