Phosphoenolpyruvate carboxylase (PEPC), NADP-malic enzyme (NADP-ME), and pyruvate, phosphate dikinase (PPDK) participate in the process of concentrating CO₂ in C₄ photosynthesis. Non-photosynthetic counterparts of these enzymes, which are present in all plants, play important roles in the maintenance of pH and replenishment of Krebs cycle intermediates, thereby contributing to the biosynthesis of amino acids and other compounds and providing NADPH for biosynthesis and the antioxidant system. Enhanced activities of PEPC and/or NADP-ME and/or PPDK were found in plants under various types of abiotic stress, such as drought, high salt concentration, ozone, the absence of phosphate and iron or the presence of heavy metals in the soil. Moreover, the activities of all of these enzymes were enhanced in plants under biotic stress caused by viral infection. The functions of PEPC, NADP-ME and PPDK appear to be more important for plants under stress than under optimal growth conditions.

• MeSH
• citrátový cyklus MeSH
• fosfoenolpyruvátkarboxylasa fyziologie   MeSH
• fotosyntéza * MeSH
• fyziologický stres * MeSH
• koncentrace vodíkových iontů MeSH
• malátdehydrogenasa fyziologie   MeSH
• oxid uhličitý metabolismus   MeSH
• pyruvátfosfátdikinasa fyziologie   MeSH
• rostlinné proteiny fyziologie   MeSH
• rostliny enzymologie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• fosfoenolpyruvátkarboxylasa MeSH
• malátdehydrogenasa MeSH
• malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+) MeSH Prohlížeč
• oxid uhličitý MeSH
• pyruvátfosfátdikinasa MeSH
• rostlinné proteiny MeSH

A series of photosynthetic electron transport (PET) inhibitors from the group of salicylanilide alkylcarbamates was investigated. The compounds were analyzed using RP-HPLC to determine lipophilicity, and their PET inhibition was determined in spinach (Spinacia oleracea L.) chloroplasts. The site of action of the studied compounds is situated at the donor site of photosystem 2 (PS 2). Compounds substituted by chlorine in C'-3 and C'-4 of the aniline ring and the optimal length of the alkyl chain pentyl-heptyl in the carbamate moiety provided the most active PET inhibitors (IC(50) inhibition <10 μmol/L). Disubstitution in C'-3,4 by chlorine caused significant PET inhibiting activity decrease. Nevertheless, for all three series of C'-3, C'-4, C'-3,4 compounds, the dependence of PET activity on lipophilicity showed to be quasi-parabolic.

• MeSH
• fotosyntetické reakční centrum - proteinové komplexy antagonisté a inhibitory   metabolismus   MeSH
• fotosyntéza účinky léků   MeSH
• karbamáty chemická syntéza   chemie   farmakologie   MeSH
• salicylanilidy chemie   MeSH
• Spinacia oleracea metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fotosyntetické reakční centrum - proteinové komplexy MeSH
• karbamáty MeSH
• salicylanilide MeSH Prohlížeč
• salicylanilidy MeSH

The influence of pH 3-10 on the growth, motility and photosynthesis in Euglena gracilis was demonstrated during a 7-d cultivation. The cells did not survive at pH < 4 and > 8, highest growth rate being detected at pH 7. Motility followed a similar pattern as growth rate. Photosynthetic response curves were shown to be of the same type over the whole pH range. High respiration was characteristic for cells grown at pH 5 and 6, the lowest one at 7. At high and also at low pH more active respiration was found which can be considered as a protective response on proton stress. Respiration was not completely inhibited with potassium cyanide. Photosynthesis was the most effective at pH 6; lower and higher pH decreased photosynthetic efficiency. pH affected more the growth rate than the photosynthesis.

• MeSH
• Euglena gracilis růst a vývoj   fyziologie   MeSH
• fotosyntéza * MeSH
• koncentrace vodíkových iontů MeSH
• kyanid draselný MeSH
• pohyb MeSH
• spotřeba kyslíku MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyanid draselný MeSH

In Arabidopsis, the plastidial isoform of phosphoglucose isomerase, PGI1, mediates growth and photosynthesis, likely due to its involvement in the vascular production of cytokinins (CK). To examine this hypothesis, we characterized pgi1-2 knockout plants impaired in PGI1 and pgi1-2 plants specifically expressing PGI1 in root tips and vascular tissues. Moreover, to investigate whether the phenotype of pgi1-2 plants is due to impairments in the plastidial oxidative pentose phosphate pathway (OPPP) or the glycolytic pathway, we characterized pgl3-1 plants with reduced OPPP and pfk4pfk5 knockout plants impaired in plastidial glycolysis. Compared with wild-type (WT) leaves, pgi1-2 leaves exhibited weaker expression of photosynthesis- and 2-C-methyl-D-erythritol 4-P (MEP) pathway-related proteins, and stronger expression of oxidative stress protection-related enzymes. Consistently, pgi1-2 leaves accumulated lower levels of chlorophyll, and higher levels of tocopherols, flavonols and anthocyanins than the WT. Vascular- and root tip-specific PGI1 expression countered the reduced photosynthesis, low MEP pathway-derived CK content, dwarf phenotype and the metabolic characteristics of pgi1-2 plants, reverting them to WT-like levels. Moreover, pgl3-1, but not pfk4pfk5 plants phenocopied pgi1-2. Histochemical analyses of plants expressing GUS under the control of promoter regions of genes encoding plastidial OPPP enzymes exhibited strong GUS activity in root tips and vascular tissues. Overall, our findings show that root tip and vascular PGI1-mediated plastidial OPPP activity affects photosynthesis and growth through mechanisms involving long-distance modulation of the leaf proteome by MEP pathway-derived CKs.

• Klíčová slova
• Cytokinin, MEP pathway, Oxidative pentose phosphate pathway, Photosynthesis,
• MeSH
• anthokyaniny metabolismus   MeSH
• Arabidopsis * metabolismus   MeSH
• cytokininy metabolismus   MeSH
• fotosyntéza MeSH
• pentózofosfátový cyklus * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anthokyaniny MeSH
• cytokininy MeSH

Microorganisms produce volatile compounds (VCs) that promote plant growth and photosynthesis through complex mechanisms involving cytokinin (CK) and abscisic acid (ABA). We hypothesized that plants' responses to microbial VCs involve posttranslational modifications of the thiol redox proteome through action of plastidial NADPH-dependent thioredoxin reductase C (NTRC), which regulates chloroplast redox status via its functional relationship with 2-Cys peroxiredoxins. To test this hypothesis, we analysed developmental, metabolic, hormonal, genetic, and redox proteomic responses of wild-type (WT) plants and a NTRC knockout mutant (ntrc) to VCs emitted by the phytopathogen Alternaria alternata. Fungal VC-promoted growth, changes in root architecture, shifts in expression of VC-responsive CK- and ABA-regulated genes, and increases in photosynthetic capacity were substantially weaker in ntrc plants than in WT plants. As in WT plants, fungal VCs strongly promoted growth, chlorophyll accumulation, and photosynthesis in ntrc-Δ2cp plants with reduced 2-Cys peroxiredoxin expression. OxiTRAQ-based quantitative and site-specific redox proteomic analyses revealed that VCs promote global reduction of the thiol redox proteome (especially of photosynthesis-related proteins) of WT leaves but its oxidation in ntrc leaves. Our findings show that NTRC is an important mediator of plant responses to microbial VCs through mechanisms involving global thiol redox proteome changes that affect photosynthesis.

• Klíčová slova
• growth promotion, hormone signalling, microbial volatile compounds, photosynthesis, plant-microbe interactions, redox proteomics,
• MeSH
• Alternaria * MeSH
• Arabidopsis účinky léků   metabolismus   MeSH
• cytokininy metabolismus   MeSH
• fotosyntéza účinky léků   MeSH
• kyselina abscisová metabolismus   MeSH
• posttranslační úpravy proteinů účinky léků   MeSH
• proteiny huseníčku metabolismus   MeSH
• proteom MeSH
• těkavé organické sloučeniny farmakologie   MeSH
• thioredoxin-disulfidreduktasa metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytokininy MeSH
• kyselina abscisová MeSH
• NTRC protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku MeSH
• proteom MeSH
• těkavé organické sloučeniny MeSH
• thioredoxin-disulfidreduktasa MeSH

The assimilation of N-NO3- requires more energy than that of N-NH4+ . This becomes relevant when energy is limiting and may impinge differently on cell energy budget depending on depth, time of the day and season. We hypothesize that N-limited and energy-limited cells of the oceanic cyanobacterium Synechococcus sp. differ in their response to the N source with respect to growth, elemental stoichiometry and carbon allocation. Under N limitation, cells retained almost absolute homeostasis of elemental and organic composition, and the use of NH4+ did not stimulate growth. When energy was limiting, however, Synechococcus grew faster in NH4+ than in NO3- and had higher C (20%), N (38%) and S (30%) cell quotas. Furthermore, more C was allocated to protein, whereas the carbohydrate and lipid pool size did not change appreciably. Energy limitation also led to a higher photosynthetic rate relative to N limitation. We interpret these results as an indication that, under energy limitation, the use of the least expensive N source allowed a spillover of the energy saved from N assimilation to the assimilation of other nutrients. The change in elemental stoichiometry influenced C allocation, inducing an increase in cell protein, which resulted in a stimulation of photosynthesis and growth.

• Klíčová slova
• FTIR, carbon allocation, cyanobacteria, elemental stoichiometry, energy, nitrogen,
• MeSH
• adenosintrifosfát metabolismus   MeSH
• amoniové sloučeniny farmakologie   MeSH
• bakteriální proteiny metabolismus   MeSH
• biomasa MeSH
• dusičnany farmakologie   MeSH
• dusík metabolismus   MeSH
• energetický metabolismus * účinky léků   MeSH
• fosfor metabolismus   MeSH
• fotosyntéza účinky léků   MeSH
• kyslík metabolismus   MeSH
• lipidy analýza   MeSH
• sacharidy analýza   MeSH
• síra metabolismus   MeSH
• Synechococcus cytologie   účinky léků   růst a vývoj   metabolismus   MeSH
• uhlík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfát MeSH
• amoniové sloučeniny MeSH
• bakteriální proteiny MeSH
• dusičnany MeSH
• dusík MeSH
• fosfor MeSH
• kyslík MeSH
• lipidy MeSH
• sacharidy MeSH
• síra MeSH
• uhlík MeSH

Lichens survive harsh weather of Antarctica as well as of other hostile environments worldwide. Therefore, this investigation is important to understand the evolution of life on Earth in relation to their stress tolerance strategy. We have used chlorophyll a fluorescence (ChlF) and Raman spectroscopy, respectively, to monitor the activation/deactivation of photosynthesis and carotenoids in three diverse Antarctic lichens, Dermatocarpon polyphyllizum (DP), Umbilicaria antarctica (UA), and Leptogium puberulum (LP). These lichens, post 4 h or 24 h of hydration, showed differences in their ChlF transients and values of major ChlF parameters, e.g., in the maximum quantum efficiency of PSII photochemistry (Fv/Fm), and yields of fluorescence and heat dissipation (Φf,d), of effective quantum efficiency of PSII photochemistry (ΦPSII) and of non-photochemical quenching (Φnpq), which may be due to quantitative and/or qualitative differences in the composition of their photobionts. For understanding the kinetics of hydration-induced activation of photosynthesis, we screened ΦPSII of these lichens and reported its non-linear stimulation on a minute time scale; half of the activation time (t1/2) was fastest ~4.05 ± 0.29 min for DP, which was followed by 5.46 ± 0.18 min for UA, and 13.95 ± 1.24 min for LP. Upon drying of fully activated lichen thallus, there was a slow decay, in hours, of relative water content (RWC) as well as of Fv/Fm. Raman spectral signatures were different for lichens having algal (in DP and UA) and cyanobacteria (in LP) photobionts, and there was a significant shift in ν1(C=C) Raman band of carotenoids post 24 h hydration as compared to their value at a dry state or post 4 h of hydration; this shift was decreased, when drying, in DP and LP but not in UA. We conclude that hydration nonlinearly activated photosynthetic apparatus/reactions of these lichens in minute time range but there was a de-novo synthesis of chlorophylls as well as of carotenoids post 24 h. Their dehydration-induced deactivation, however, was comparatively slow, in hours range, and there seemed a degradation of synthesized chlorophylls and carotenoids post dryness. We conclude that in extremophilic lichens, their photosynthetic partners, in particular, possess a complex survival and photoprotective strategy to be successful in the extreme terrestrial environments in Antarctica.

• Klíčová slova
• Effective quantum efficiency of PSII photochemistry, Extremophile organisms, Harsh environments, Non-invasive methods, Optical signal, Raman spectra,
• MeSH
• Ascomycota MeSH
• chlorofyl a MeSH
• chlorofyl MeSH
• fluorescence MeSH
• fotosyntéza MeSH
• karotenoidy metabolismus   MeSH
• lišejníky * metabolismus   MeSH
• Ramanova spektroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH
• Názvy látek
• chlorofyl a MeSH
• chlorofyl MeSH
• karotenoidy MeSH

Effects of increasing doses of UV-B radiation on photosynthetic efficiency (PE) and motility in Chlamydomonas reinhardtii were investigated. The exposure time ranged from 10 to 120 min at 0.73 W/m2 UV-B radiation. A decrease in compensation points (CP) was followed by an increase in PE on extending the UV-B treatment up to 60 min. The subsequent increase in PE was accompanied by increasing CPs. Enhanced doses of UV-B radiation thus have a stimulatory effect on the PE in C. reinhardtii. No inhibitory effects could be detected. No statistically significant differences in motility could be observed due to an extremely high variation of values.

• MeSH
• Chlamydomonas reinhardtii fyziologie   účinky záření   MeSH
• fotosyntéza účinky záření   MeSH
• pohyb buněk účinky záření   MeSH
• ultrafialové záření MeSH
• vztah dávky záření a odpovědi MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• ACTINOMYCETALES *, CARBOMYCIN *, CHLOROPHYLL *, ERYTHROMYCIN *, EUGLENA *, EXPERIMENTAL LAB STUDY *, KANAMYCIN *, PHARMACOLOGY *, PHOTOSYNTHESIS *, SPIRAMYCIN *, STREPTOMYCIN *, VIOMYCIN *,
• MeSH
• Actinobacteria * MeSH
• Actinomyces * MeSH
• Actinomycetales * MeSH
• antibakteriální látky * MeSH
• chlorofyl * MeSH
• erythromycin * MeSH
• Euglena * MeSH
• farmakologie * MeSH
• fotosyntéza * MeSH
• kanamycin * MeSH
• leukomyciny * MeSH
• spiramycin * MeSH
• streptomycin * MeSH
• viomycin * MeSH
• výzkum * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky * MeSH
• carbomycin MeSH Prohlížeč
• chlorofyl * MeSH
• erythromycin * MeSH
• kanamycin * MeSH
• leukomyciny * MeSH
• spiramycin * MeSH
• streptomycin * MeSH
• viomycin * MeSH

Plum pox virus (PPV, family Potyviridae) is one of the most important viral pathogens of Prunus spp. causing considerable damage to stone-fruit industry worldwide. Among the PPV strains identified so far, only PPV-C, PPV-CR, and PPV-CV are able to infect cherries under natural conditions. Herein, we evaluated the pathogenic potential of two viral isolates in herbaceous host Nicotiana benthamiana. Significantly higher accumulation of PPV capsid protein in tobacco leaves infected with PPV-CR (RU-30sc isolate) was detected in contrast to PPV-C (BY-101 isolate). This result correlated well with the symptoms observed in the infected plants. To further explore the host response upon viral infection at the molecular level, a comprehensive proteomic profiling was performed. Using reverse-phase ultra-high-performance liquid chromatography followed by label-free mass spectrometry quantification, we identified 38 unique plant proteins as significantly altered due to the infection. Notably, the abundances of photosynthesis-related proteins, mainly from the Calvin-Benson cycle, were found more aggressively affected in plants infected with PPV-CR isolate than those of PPV-C. This observation was accompanied by a significant reduction in the amount of photosynthetic pigments extracted from the leaves of PPV-CR infected plants. Shifts in the abundance of proteins that are involved in stimulation of photosynthetic capacity, modification of amino acid, and carbohydrate metabolism may affect plant growth and initiate energy formation via gluconeogenesis in PPV infected N. benthamiana. Furthermore, we suggest that the higher accumulation of H2O2 in PPV-CR infected leaves plays a crucial role in plant defense and development by activating the glutathione synthesis.

• Klíčová slova
• LC−MS, antioxidants, compatible interaction, label-free quantification, photosynthesis, sharka, tobacco,
• MeSH
• chlorofyl biosyntéza   MeSH
• chromatografie s reverzní fází MeSH
• energetický metabolismus genetika   MeSH
• fotosyntéza genetika   MeSH
• genotyp MeSH
• glutathion biosyntéza   MeSH
• hmotnostní spektrometrie MeSH
• interakce hostitele a patogenu genetika   MeSH
• karotenoidy biosyntéza   MeSH
• listy rostlin genetika   metabolismus   virologie   MeSH
• nemoci rostlin genetika   virologie   MeSH
• oxidace-redukce MeSH
• peroxid vodíku metabolismus   MeSH
• proteiny tepelného šoku klasifikace   genetika   metabolismus   MeSH
• Prunus avium virologie   MeSH
• regulace genové exprese u rostlin * MeSH
• rostlinné proteiny klasifikace   genetika   metabolismus   MeSH
• slivoň švestka virologie   MeSH
• tabák genetika   metabolismus   virologie   MeSH
• virus šarky švestky klasifikace   genetika   růst a vývoj   patogenita   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorofyl MeSH
• glutathion MeSH
• karotenoidy MeSH
• peroxid vodíku MeSH
• proteiny tepelného šoku MeSH
• rostlinné proteiny MeSH