Comparison of thylakoid structure and organization in sun and shade Haberlea rhodopensis populations under desiccation and rehydration

Sárvári, Éva; Mihailova, Gergana; Solti, Ádám; Keresztes, Attila; Velitchkova, Maya; Georgieva, Katya

doi:10.1016/j.jplph.2014.07.015

Cited by 30 publications

(25 citation statements)

References 52 publications

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“…Composition of R. myconi leaves was characterised by a relatively high Chl content and low Chl a : b ratio (Fig. 2) but within an expected range for a shade‐preferring species (Sárvári et al , 2014; Esteban et al , 2015; Georgieva et al , 2017b; Fernández‐Marín et al , 2018a). The VAZ pool and the Toc : Chl ratios were moderately high and comparable to values of Mediterranean herbaceous species (Munné‐Bosch et al , 2016; Fernández‐Marín et al , 2017).…”

Section: Discussionmentioning

confidence: 67%

Born to revive: molecular and physiological mechanisms of double tolerance in a paleotropical and resurrection plant

et al. 2020

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Summary Resurrection plants recover physiological functions after complete desiccation. Almost all of them are native to tropical warm environments. However, the Gesneriaceae include four genera, remnant of the past palaeotropical flora, which inhabit temperate mountains. One of these species is additionally freezing‐tolerant: Ramonda myconi. We hypothesise that this species has been able to persist in a colder climate thanks to some resurrection‐linked traits. To disentangle the physiological mechanisms underpinning multistress tolerance to desiccation and freezing, we conducted an exhaustive seasonal assessment of photosynthesis (gas exchange, limitations to partitioning, photochemistry and galactolipids) and primary metabolism (through metabolomics) in two natural populations at different elevations. R. myconi displayed low rates of photosynthesis, largely due to mesophyll limitation. However, plants were photosynthetically active throughout the year, excluding a reversible desiccation period. Common responses to desiccation and low temperature involved chloroplast protection: enhanced thermal energy dissipation, higher carotenoid to Chl ratio and de‐epoxidation of the xanthophyll cycle. As specific responses, antioxidants and secondary metabolic routes rose upon desiccation, while putrescine, proline and a variety of sugars rose in winter. The data suggest conserved mechanisms to cope with photo‐oxidation during desiccation and cold events, while additional metabolic mechanisms may have evolved as specific adaptations to cold during recent glaciations.

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Section: Discussionmentioning

confidence: 67%

Born to revive: molecular and physiological mechanisms of double tolerance in a paleotropical and resurrection plant

et al. 2020

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“…Such unbound LHCII may form aggregates that serve as photoprotective energy quenchers during dehydration, as has been shown for high-light conditions and during state transitions in higher plants and in C. reinhardtii (Betterle et al, 2009;Iwai et al, 2010;Johnson et al, 2011;Yamamoto et al, 2013Yamamoto et al, , 2014. A quenching state of LHCII also has been proposed during dehydration of the homoiochlorophyllous resurrection plant H. rhodopensis (Sárvári et al, 2014). Thus, rearrangements in PSII-LHCII macrostructure likely play a key role in minimizing ROS formation and, therefore, photodamage in homoiochlorophyllous resurrection plants in the desiccated state.…”

Section: The Physiological Significance Of Psii Arraysmentioning

confidence: 81%

“…Elevated levels of the thylakoid protease FtsH have been observed at late stages of dehydration of the poikilochlorophyllous resurrection plant Xerophyta viscosa (Ingle et al, 2007), in which degradation of thylakoid proteins is a natural occurrence during desiccation. However, the observation of a similar phenomenon in homoiochlorophyllous types such as Selaginella tamariscina (Wang et al, 2010), H. rhodopensis (Georgieva et al, 2009;Sárvári et al, 2014), and Boea hygrometrica (Jiang et al, 2007) suggests . The density of PSII complexes in grana thylakoid membranes changes during dehydration and rehydration.…”

Section: Decline In Photosynthetic Activity and Protein Levelsmentioning

confidence: 95%

Photoprotection Conferred by Changes in Photosynthetic Protein Levels and Organization during Dehydration of a Homoiochlorophyllous Resurrection Plant

et al. 2015

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During desiccation, homoiochlorophyllous resurrection plants retain most of their photosynthetic apparatus, allowing them to resume photosynthetic activity quickly upon water availability. These plants rely on various mechanisms to prevent the formation of reactive oxygen species and/or protect their tissues from the damage they inflict. In this work, we addressed the issue of how homoiochlorophyllous resurrection plants deal with the problem of excessive excitation/electron pressures during dehydration using Craterostigma pumilum as a model plant. To investigate the alterations in the supramolecular organization of photosynthetic protein complexes, we examined cryoimmobilized, freeze-fractured leaf tissues using (cryo)scanning electron microscopy. These examinations revealed rearrangements of photosystem II (PSII) complexes, including a lowered density during moderate dehydration, consistent with a lower level of PSII proteins, as shown by biochemical analyses. The latter also showed a considerable decrease in the level of cytochrome f early during dehydration, suggesting that initial regulation of the inhibition of electron transport is achieved via the cytochrome b 6 f complex. Upon further dehydration, PSII complexes are observed to arrange into rows and semicrystalline arrays, which correlates with the significant accumulation of sucrose and the appearance of inverted hexagonal lipid phases within the membranes. As opposed to PSII and cytochrome f, the light-harvesting antenna complexes of PSII remain stable throughout the course of dehydration. Altogether, these results, along with photosynthetic activity measurements, suggest that the protection of retained photosynthetic components is achieved, at least in part, via the structural rearrangements of PSII and (likely) light-harvesting antenna complexes into a photochemically quenched state.

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“…The results showed that the top band, which was identified as NDH (labeled WT-1 and ML-1 in Fig. S2A), and the bottom band, which was identified as PSI SC (19,20) (labeled WT-6 and ML-4), displayed identical patterns of subunit composition in the WT and ML (Fig. S2B).…”

Section: Significancementioning

confidence: 99%

PSB27: A thylakoid protein enabling Arabidopsis to adapt to changing light intensity

Hou

Garcia

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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In earlier studies we have identified FKBP20-2 and CYP38 as soluble proteins of the chloroplast thylakoid lumen that are required for the formation of photosystem II supercomplexes (PSII SCs). Subsequent work has identified another potential candidate functional in SC formation (PSB27). We have followed up on this possibility and isolated mutants defective in the PSB27 gene. In addition to lack of PSII SCs, mutant plants were severely stunted when cultivated with light of variable intensity. The stunted growth was associated with lower PSII efficiency and defective starch accumulation. In response to high light exposure, the mutant plants also displayed enhanced ROS production, leading to decreased biosynthesis of anthocyanin. Unexpectedly, we detected a second defect in the mutant, namely in CP26, an antenna protein known to be required for the formation of PSII SCs that has been linked to state transitions. Lack of PSII SCs was found to be independent of PSB27, but was due to a mutation in the previously described cp26 gene that we found had no effect on light adaptation. The present results suggest that PSII SCs, despite being required for state transitions, are not associated with acclimation to changing light intensity. Our results are consistent with the conclusion that PSB27 plays an essential role in enabling plants to adapt to fluctuating light intensity through a mechanism distinct from photosystem II supercomplexes and state transitions.photosystem | PSII supercomplex | photosynthesis | anthocyanin biosynthesis | reactive oxygen species P hotosynthetic light reactions entail the coordinated function of several large membrane complexes: photosystem I (PSI), photosystem II (PSII), cytochrome b6f complex, and CF 0 -CF 1 complex. PSII catalyzes the initial step of photosynthesis, the light-dependent oxidation of water that yields molecular oxygen and reduced plastoquinone. The native form of PSII residing in the thylakoid membrane is believed to be organized into several types of supercomplexes (SCs), including the PSII core and the peripheral light harvesting complex II (LHCII), that play a primary role in the harvesting of light, transfer of excitation energy to the reaction center and regulation of light utilization. Several monomeric antenna proteins including CP24, CP26, and CP29 regulate the interaction of the PSII core with LHCII trimers (1-4). Regulation is achieved through photoprotective mechanisms that dissipate absorbed excess energy as heat in response to stress conditions such as high light intensity (5, 6).In natural settings, both the intensity and the spectral quality of light vary extensively, sometimes within very short periods. The changes in light intensity result in imbalanced excitation of PSI and PSII, and with that may lower the efficiency of the photosynthetic light reactions. In acclimating to the changing conditions, plants modify their thylakoid proteins and reorganize their photosynthetic machinery (7,8). In a rapid response, designated state transitions (9), LHCII associates...

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Comparison of thylakoid structure and organization in sun and shade Haberlea rhodopensis populations under desiccation and rehydration

Cited by 30 publications

References 52 publications

Born to revive: molecular and physiological mechanisms of double tolerance in a paleotropical and resurrection plant

Born to revive: molecular and physiological mechanisms of double tolerance in a paleotropical and resurrection plant

Photoprotection Conferred by Changes in Photosynthetic Protein Levels and Organization during Dehydration of a Homoiochlorophyllous Resurrection Plant

PSB27: A thylakoid protein enabling Arabidopsis to adapt to changing light intensity

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