scholarly journals Indications for a Central Role of Hexokinase Activity in Natural Variation of Heat Acclimation in Arabidopsis thaliana

2020 ◽  
Author(s):  
Vasil Atanasov ◽  
Lisa Fürtauer ◽  
Thomas Nägele
Keyword(s):  
Arabidopsis Thaliana ◽  
Metabolic Regulation ◽  
Co2 Assimilation ◽  
High Light ◽  
Plant Performance ◽  
Hexokinase Activity ◽  
South Italy ◽  
Single Stress ◽  
Photosynthetic Capacities

Diurnal and seasonal changes of abiotic environmental factors shape plant performance and distribution. Changes of growth temperature and light intensity may vary significantly on a diurnal, but also on a weekly or seasonal scale. Hence, acclimation to a changing temperature and light regime is essential for plant survival and propagation. In the present study, we analyzed photosynthetic CO2 assimilation and metabolic regulation of the central carbohydrate metabolism in two natural accessions of Arabidopsis thaliana originating from Russia and south Italy during exposure to heat and a combination of heat and high light. Our findings indicate that it is hardly possible to predict photosynthetic capacities to fix CO2 under combined stress from single stress experiments. Further, capacities of hexose phosphorylation were found to be significantly lower in the Italian than in the Russian accession which could explain an inverted sucrose-to-hexose ratio. Together with the finding of significantly stronger accumulation of anthocyanins under heat/high light these observations indicate a central role of hexokinase activity in stabilization of photosynthetic capacities within a changing environment.

scholarly journals Indications for a Central Role of Hexokinase Activity in Natural Variation of Heat Acclimation in Arabidopsis thaliana

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 819
Author(s):  
Vasil Atanasov ◽  
Lisa Fürtauer ◽  
Thomas Nägele
Keyword(s):  
Arabidopsis Thaliana ◽  
Carbohydrate Metabolism ◽  
Metabolic Regulation ◽  
Environmental Changes ◽  
Co2 Assimilation ◽  
High Light ◽  
Plant Performance ◽  
Hexokinase Activity ◽  
South Italy

Diurnal and seasonal changes of abiotic environmental factors shape plant performance and distribution. Changes of growth temperature and light intensity may vary significantly on a diurnal, but also on a weekly or seasonal scale. Hence, acclimation to a changing temperature and light regime is essential for plant survival and propagation. In the present study, we analyzed photosynthetic CO2 assimilation and metabolic regulation of the central carbohydrate metabolism in two natural accessions of Arabidopsis thaliana that originate from north western Russia and south Italy during exposure to heat and a combination of heat and high light. Our findings indicate that it is hardly possible to predict photosynthetic capacities under combined stress from single stress experiments. Further, capacities of hexose phosphorylation were found to be significantly lower in the Italian than in the Russian accession, which could explain an inverted sucrose-to-hexose ratio. Together with the finding of significantly stronger accumulation of anthocyanins under heat/high light, these observations indicate a central role of hexokinase activity in the stabilization of photosynthesis and carbohydrate metabolism during environmental changes.

Stomatal aperture can compensate altered stomatal density in Arabidopsis thaliana at growth light conditions

2006 ◽  
Vol 33 (11) ◽  
pp. 1037 ◽  
Author(s):  
Dirk Büssis ◽  
Uritza von Groll ◽  
Joachim Fisahn ◽  
Thomas Altmann
Keyword(s):  
Arabidopsis Thaliana ◽  
Stomatal Conductance ◽  
Stomatal Density ◽  
Co2 Assimilation ◽  
High Light ◽  
Stomatal Aperture ◽  
Photochemical Quenching ◽  
Light Conditions ◽  
Wild Type ◽  
Light Intensities

Stomatal density of transgenic Arabidopsis thaliana plants over-expressing the SDD1 (stomatal density and distribution) gene was reduced to 40% and in the sdd1-1 mutant increased to 300% of the wild type. CO2 assimilation rate and stomatal conductance of over-expressers and the sdd1-1 mutant were unchanged compared with wild types when measured under the light conditions the plants were exposed to during growth. Lower stomatal density was compensated for by increased stomatal aperture and conversely, increased stomatal density was compensated for by reduced stomatal aperture. At high light intensities the assimilation rates and stomatal conductance of SDD1 over-expressers were reduced to 80% of those in wild type plants. Areas beneath stomata and patches lacking stomata were analysed separately. In areas without stomata, maximum fluorescence yield (Fv / Fm) and quantum yield of photosystem II (Φ PSII) were significantly lower than in areas beneath stomata. In areas beneath stomata, Fv / Fm and Φ PSII were identical to levels measured in wild type leaves. At high light intensities over-expressers showed decreased photochemical quenching (qP) compared with wild types. However, the decrease of qP was significantly stronger in areas without stomata than in mesophyll areas beneath stomata. At high CO2 partial pressures and high light intensities CO2 assimilation rates of SDD1 over-expressers did not reach wild type levels. These results indicate that photosynthesis in SDD1 over-expressers was reduced because of limiting CO2 in areas furthest from stomata at high light.

Physiological role of AOX1a in photosynthesis and maintenance of cellular redox homeostasis under high light in Arabidopsis thaliana

2014 ◽  
Vol 81 ◽  
pp. 44-53 ◽  
Author(s):  
Abhaypratap Vishwakarma ◽  
Leena Bashyam ◽  
Balasubramanian Senthilkumaran ◽  
Renate Scheibe ◽  
Kollipara Padmasree
Keyword(s):  
Arabidopsis Thaliana ◽  
Redox Homeostasis ◽  
Physiological Role ◽  
High Light ◽  
Cellular Redox

scholarly journals Melatonin Enhanced the Tolerance of Arabidopsis thaliana to High Light Through Improving Anti-oxidative System and Photosynthesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Si-Jia Yang ◽  
Bo Huang ◽  
Yu-Qing Zhao ◽  
Di Hu ◽  
Tao Chen ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Light Stress ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
Protective Effects ◽  
Biotic And Abiotic Stresses ◽  
Exogenous Melatonin ◽  
Sunlight Intensity ◽  
Oxidative System

Land plants live in a crisis-filled environment and the fluctuation of sunlight intensity often causes damage to photosynthetic apparatus. Phyto-melatonin is an effective bioactive molecule that helps plants to resist various biotic and abiotic stresses. In order to explore the role of melatonin under high light stress, we investigated the effects of melatonin on anti-oxidative system and photosynthesis of Arabidopsis thaliana under high light. Results showed that exogenous melatonin increased photosynthetic rate and protected photosynthetic proteins under high light. This was mainly owing to the fact that exogenous melatonin effectively decreased the accumulation of reactive oxygen species and protected integrity of membrane and photosynthetic pigments, and reduced cell death. Taken together, our study promoted more comprehensive understanding in the protective effects of exogenous melatonin under high light.

scholarly journals Vacuolar invertase activity shapes photosynthetic stress response of Arabidopsis thaliana and stabilizes central energy supply

2017 ◽  
Author(s):  
Jakob Weiszmann ◽  
Lisa Fürtauer ◽  
Wolfram Weckwerth ◽  
Thomas Nägele
Keyword(s):  
Arabidopsis Thaliana ◽  
Stress Response ◽  
Energy Metabolism ◽  
Plant Stress ◽  
Invertase Activity ◽  
High Light ◽  
Vacuolar Invertase ◽  
Central Energy ◽  
Sucrose Cleavage

AbstractStabilization of the central carbohydrate and energy metabolism plays a key role in plant stress response. As the primary photosynthetic products, carbohydrates are substrate for numerous metabolic and stress-protective reactions. Further, they have been shown to be involved in diverse signalling processes finally affecting and regulating plant stress response on a whole plant level. Sucrose metabolism is known to be central to many stress-related processes and enzymes catalysing its biosynthesis, transport and degradation have been shown to significantly impact stress resistance and acclimation output. However, due to the cyclic structure of sucrose metabolism involving sucrose cleavage in multiple compartments as well as energy-demanding re-synthesis via hexose phosphorylation, it is challenging to derive an unambiguous picture of its contribution to stress reactions. In the present study, a combined stress experiment comprising cold and high-light identified metabolism of sucrose and fumaric acid to significantly separate the stress response of a cold susceptible and a tolerant natural accession of Arabidopsis thaliana. Kinetic modelling and simulation of subcellular rates of invertase-driven sucrose cleavage revealed a contrasting picture between the susceptible and the tolerant accession pointing to an important role of vacuolar invertase during initial stress response. Using a T-DNA insertion mutant with a dramatically reduced invertase activity provided evidence for a central role of the enzyme in stabilizing photosynthesis and the central energy metabolism during freezing and high-light stress. Reducing vacuolar invertase activity to about 3% of the wild type resulted in a strong increase of ADP and ATP levels indicating a severe effect on cytosolic and plastidial energy balance. Together with a significant decrease of maximum quantum yield of photosystem II (Fv/Fm) these results suggest that vacuolar invertase activity stabilizes cytosolic energy metabolism by supplying hexose equivalents being phosphorylated in the cytosol. Finally, the accompanying ATP consumption is essential for cytosolic phosphate balance which directly affects photosynthetic performance by the supply of ADP being crucial for photosynthetic ATP production.

scholarly journals The essential role of sugar metabolism in the acclimation response of Arabidopsis thaliana to high light intensities

2014 ◽  
Vol 65 (6) ◽  
pp. 1619-1636 ◽  
Author(s):  
Jessica Schmitz ◽  
Luisa Heinrichs ◽  
Federico Scossa ◽  
Alisdair R. Fernie ◽  
Marie-Luise Oelze ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Essential Role ◽  
Sugar Metabolism ◽  
High Light ◽  
Light Intensities ◽  
Acclimation Response

scholarly journals Role of CBF transcription factors during long-term acclimation to high light and low temperature in two ecotypes of Arabidopsis thaliana

2021 ◽  
Author(s):  
christopher baker ◽  
Jared Stewart ◽  
Cynthia Amstutz ◽  
Jeffrey Johnson ◽  
Lindsey Ching ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factors ◽  
Freezing Tolerance ◽  
Transcriptional Control ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Light Level ◽  
High Light ◽  
Cool Temperature

When grown under cool temperature, winter annuals upregulate photosynthetic capacity as well as freezing tolerance. Here, the role of three cold-induced C-repeat-Binding Factor (CBF1–3) transcription factors in photosynthetic upregulation and freezing tolerance was examined in two Arabidopsis thaliana ecotypes originating from Italy (IT) or Sweden (SW), and their corresponding CBF1–3-deficient mutant lines it:cbf123 and sw:cbf123. Photosynthetic, morphological, and freezing-tolerance phenotypes as well as gene expression profiles were characterized in plants grown from seedling stage under different combinations of light level and temperature. Under high light and cool growth temperature (HLC), a greater role of CBF1–3 in IT versus SW was evident from both phenotypic and transcriptomic data, especially with respect to photosynthetic upregulation and freezing tolerance of whole plants. Overall, features of SW were consistent with a different approach to HLC acclimation than seen in IT, and an ability of SW to reach the new homeostasis through involvement of transcriptional controls other than CBF1–3. These results provide tools and direction for further mechanistic analysis of the transcriptional control of approaches to cold acclimation suitable for either persistence through brief cold spells or for maximization of productivity in environments with continuous low temperatures.

scholarly journals Structural and Functional Heat Stress Responses of Chloroplasts of Arabidopsis thaliana

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 650
Author(s):  
Puneet Paul ◽  
Anida Mesihovic ◽  
Palak Chaturvedi ◽  
Arindam Ghatak ◽  
Wolfram Weckwerth ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
Stress Responses ◽  
Protein Translocation ◽  
Plant Performance ◽  
Global Networks ◽  
Growth And Survival ◽  
Physiological Capacity ◽  
Single Stress ◽  
Chloroplast Morphology

Temperature elevations constitute a major threat to plant performance. In recent years, much was learned about the general molecular mode of heat stress reaction of plants. The current research focuses on the integration of the knowledge into more global networks, including the reactions of cellular compartments. For instance, chloroplast function is central for plant growth and survival, and the performance of chloroplasts is tightly linked to the general status of the cell and vice versa. We examined the changes in photosynthesis, chloroplast morphology and proteomic composition posed in Arabidopsis thaliana chloroplasts after a single or repetitive heat stress treatment over a period of two weeks. We observed that the acclimation is potent in the case of repetitive application of heat stress, while a single stress results in lasting alterations. Moreover, the physiological capacity and its adjustment are dependent on the efficiency of the protein translocation process as judged from the analysis of mutants of the two receptor units of the chloroplast translocon, TOC64, and TOC33. In response to repetitive heat stress, plants without TOC33 accumulate Hsp70 proteins and plants without TOC64 have a higher content of proteins involved in thylakoid structure determination when compared to wild-type plants.

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