scholarly journals 2-Cysteine Peroxiredoxins and Thylakoid Ascorbate Peroxidase Create a Water-Water Cycle That Is Essential to Protect the Photosynthetic Apparatus under High Light Stress Conditions

2015 ◽  
Vol 167 (4) ◽  
pp. 1592-1603 ◽  
Author(s):  
Jasmin Awad ◽  
Henrik U. Stotz ◽  
Agnes Fekete ◽  
Markus Krischke ◽  
Cornelia Engert ◽  
...  
Keyword(s):  
Ascorbate Peroxidase ◽  
Water Cycle ◽  
Light Stress ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
Stress Conditions ◽  
High Light Stress

Effect of High Light and High Light Stress on Composition, Function and Structure of the Photosynthetic Apparatus

1983 ◽  
pp. 353-370 ◽  
Author(s):  
H. K. Lichtenthaler ◽  
R. Burgstahler ◽  
C. Buschmann ◽  
D. Meier ◽  
U. Prenzel ◽  
...  
Keyword(s):  
Light Stress ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
High Light Stress

scholarly journals Photosynthetic signalling during high light stress and recovery: targets and dynamics

2020 ◽  
Vol 375 (1801) ◽  
pp. 20190406 ◽  
Author(s):  
Peter J. Gollan ◽  
Eva-Mari Aro
Keyword(s):  
Gene Expression ◽  
Electron Transport ◽  
Redox Homeostasis ◽  
Light Stress ◽  
Photosynthetic Apparatus ◽  
Photosynthetic Electron Transport ◽  
High Light ◽  
Abiotic Stress Response ◽  
High Light Stress ◽  
Retrograde Signalling

The photosynthetic apparatus is one of the major primary sensors of the plant's external environment. Changes in environmental conditions affect the balance between harvested light energy and the capacity to deal with excited electrons in the stroma, which alters the redox homeostasis of the photosynthetic electron transport chain. Disturbances to redox balance activate photosynthetic regulation mechanisms and trigger signalling cascades that can modify the transcription of nuclear genes. H 2 O 2 and oxylipins have been identified as especially prominent regulators of gene expression in response to excess light stress. This paper explores the hypothesis that photosynthetic imbalance triggers specific signals that target discrete gene profiles and biological processes. Analysis of the major retrograde signalling pathways engaged during high light stress and recovery demonstrates both specificity and overlap in gene targets. This work reveals distinct, time-resolved profiles of gene expression that suggest a regulatory interaction between rapidly activated abiotic stress response and induction of secondary metabolism and detoxification processes during recovery. The findings of this study show that photosynthetic electron transport provides a finely tuned sensor for detecting and responding to the environment through chloroplast retrograde signalling. This article is part of the theme issue ‘Retrograde signalling from endosymbiotic organelles’

Strategies of light energy utilisation, dissipation and attenuation in sixco-occurring alpine heath species in Tasmania

2003 ◽  
Vol 30 (12) ◽  
pp. 1205 ◽  
Author(s):  
Erica L. Williams ◽  
Mark J. Hovenden ◽  
Dugald C. Close
Keyword(s):  
Light Stress ◽  
Photosynthetic Apparatus ◽  
Distinct Species ◽  
High Light ◽  
Light Energy ◽  
Shrub Species ◽  
High Light Stress ◽  
Thermal Energy Dissipation ◽  
Alpine Shrub ◽  
Cycle Dependent

Alpine environments are characterised by low temperatures and high light intensities. This combination leads to high light stress owing to the imbalance between light energy harvesting and its use in photochemistry. In extreme cases, high light stress can lead to the level of photo-oxidative damage exceeding the rate of repair to the photosynthetic apparatus. Plant species may vary in the mechanisms they use to prevent photodamage, but most comparisons are of geographically and ecologically distinct species. Differences in leaf colouration suggested that photoprotective strategies might differ among Tasmanian evergreen alpine shrub species. We compared chlorophyll fluorescence and leaf pigment composition in six co-occurring alpine shrub species on the summit of Mt Wellington, southern Tasmania, Australia, during spring and autumn. We found marked differences among species in light energy utilisation, attenuation and dissipation. Ozothamnus ledifolius maintained a large capacity for photosynthetic light utilisation and thus, had a low requirement for light dissipation. All five of the other species relied on xanthophyll-cycle-dependent thermal energy dissipation. In addition Epacris serpyllifolia, Richea sprengelioides and Leptospermum rupestre had foliar anthocyanins that would attenuate photosynthetically active light in the leaf. During spring, all species retained de-epoxidised xanthophylls through the night and the pre-dawn concentration of antheraxanthin and zeaxanthin was significantly correlated with reductions in pre-dawn Fv / Fm. We propose that these species use three photoprotective strategies to cope with the combination of high light and low temperature.

scholarly journals Stable Reference Gene Selection for RT-qPCR Analysis inSynechococcus elongatusPCC 7942 under Abiotic Stresses

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xiao Luo ◽  
Jiaxing Li ◽  
Tianliang Chang ◽  
Hongyan He ◽  
Yi Zhao ◽  
...  
Keyword(s):  
Reference Gene ◽  
Reference Genes ◽  
Time Course ◽  
Light Stress ◽  
Nacl Stress ◽  
High Light ◽  
Stress Conditions ◽  
Internal Reference ◽  
High Light Stress ◽  
Pcc 7942

Synechococcus elongatusPCC 7942 (S. elongatusPCC 7942) is a model cyanobacteria species for circadian clock mechanism studies. It has also been widely used as a bioreactor to produce biofuels and other metabolic products. Quantitative real-time PCR (qPCR) technology is the most commonly used method for studying the expression of specific genes, in which the relative expression level of target genes is calibrated by stably expressed internal reference genes. In this work, we examined the expression of nine candidate reference genes in time-course samples ofS. elongatusPCC 7942 under no treatment (control), NaCl-stress conditions, H2O2-stress conditions, and high light-stress conditions. Based on the qPCR amplification parameters, the stability ranking of these candidate reference genes was established by three statistical software programs, geNorm, NormFinder, and BestKeeper. Considering all the stress conditions or high light stress alone, the results showed that the combination ofprsandsecAwas the best choice for the double reference gene calibration method by qPCR. The combination ofsecAandppc,rimMandrnpA,rnpA,andilvDwas most stable under no treatment, NaCl-stress conditions, and H2O2-stress conditions, respectively.rimMwas stable under only special conditions and should be carefully chosen.16SandrnpBwere not suitable as internal reference genes forS. elongatusPCC 7942 qPCR experiments under all experimental conditions. To validate the above results, a cyanobacterial core clock gene,kaiC, was used to evaluate the actual performance of the optimized reference genes by qPCR, as well as the worst reference genes under different stress conditions. The results indicated that the best reference gene yielded more accurate calibration results for qPCR experiments carried out inS. elongatusPCC 7942 time-course samples.

Nitric oxide mediates abscisic acid induced light-tolerance in leaves of tall fescue under high-light stress

2013 ◽  
Vol 162 ◽  
pp. 1-10 ◽  
Author(s):  
Yuefei Xu ◽  
Juanjuan Fu ◽  
Xitong Chu ◽  
Yongfang Sun ◽  
He Zhou ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Abscisic Acid ◽  
Tall Fescue ◽  
Light Stress ◽  
High Light ◽  
High Light Stress
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