The objective of our study was to characterise the growth of tomato seedlings under various light spectra, but special attention has been paid to gaining a deeper insight into the details of photosynthetic light reactions. The following light combinations (generated by LEDs, constant light intensity at 300 μmol m-2 s-1) were used: blue/red light; blue/red light + far red; blue/red light + UV; white light that was supplemented with green, and white light that was supplemented with blue. Moreover, two combinations of white light for which the light intensity was changed by imitating the sunrise, sunset, and moon were also tested. The reference point was also light generated by high pressure sodium lamps (HPS). Plant growth/morphological parameters under various light conditions were only partly correlated with the photosynthetic efficiency of PSI and PSII. Illumination with blue/red as the main components had a negative effect on the functioning of PSII compared to the white light and HPS-generated light. On the other hand, the functioning of PSI was especially negatively affected under the blue/red light that was supplemented with FR. The FT-Raman studies showed that the general metabolic profile of the leaves (especially proteins and β-carotene) was similar in the plants that were grown under the HPS and under the LED-generated white light for which the light intensity changed during a day. The effect of various light conditions on the leaf hormonal balance (auxins, brassinosteroids) is also discussed.

• Klíčová slova
• Solanum lycopersicum L., auxins, brassinosteroids, light spectral composition, photosynthesis, plant growth,
• MeSH
• brassinosteroidy metabolismus   MeSH
• chlorofyl metabolismus   MeSH
• fotosyntéza * účinky záření   MeSH
• fotosystém I (proteinový komplex) metabolismus   účinky záření   MeSH
• fotosystém II (proteinový komplex) metabolismus   účinky záření   MeSH
• kyseliny indoloctové metabolismus   MeSH
• listy rostlin růst a vývoj   metabolismus   účinky záření   MeSH
• metabolom MeSH
• Ramanova spektroskopie MeSH
• regulátory růstu rostlin metabolismus   MeSH
• semenáček růst a vývoj   metabolismus   účinky záření   MeSH
• Solanum lycopersicum růst a vývoj   metabolismus   účinky záření   MeSH
• světlo MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• brassinosteroidy MeSH
• chlorofyl MeSH
• fotosystém I (proteinový komplex) MeSH
• fotosystém II (proteinový komplex) MeSH
• kyseliny indoloctové MeSH
• regulátory růstu rostlin MeSH

Gemmatimonas phototrophica AP64 is the first phototrophic representative of the bacterial phylum Gemmatimonadetes. The cells contain photosynthetic complexes with bacteriochlorophyll a as the main light-harvesting pigment and an unknown carotenoid with a single broad absorption band at 490 nm in methanol. The carotenoid was extracted from isolated photosynthetic complexes, and purified by liquid chromatography. A combination of nuclear magnetic resonance (1H NMR, COSY, 1H-13C HSQC, 1H-13C HMBC, J-resolved, and ROESY), high-resolution mass spectroscopy, Fourier-transformed infra-red, and Raman spectroscopy was used to determine its chemical structure. The novel linear carotenoid, that we have named gemmatoxanthin, contains 11 conjugated double bonds and is further substituted by methoxy, carboxyl and aldehyde groups. Its IUPAC-IUBMB semi-systematic name is 1'-Methoxy-19'-oxo-3',4'-didehydro-7,8,1',2'-tetrahydro- Ψ, Ψ carotene-16-oic acid. To our best knowledge, the presence of the carboxyl, methoxy and aldehyde groups on a linear C40 carotenoid backbone is reported here for the first time.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Bee pollen samples were discriminated using vibrational spectroscopic methods by connecting with botanical sources, composition, and color. SEM and light microscope images of bee pollen loads were obtained and used to assess the botanical origin. Fourier transform (FT) mid- and near-infrared (FT-MIR, FT-NIR), and FT-Raman spectra of bee pollen samples (a set of randomly chosen loads can be defined as an independent sample) were measured and processed by principal component analysis (PCA). The CIE L*a*b* color space parameters were calculated from the image analysis. FT-MIR, FT-NIR, and FT-Raman spectra showed marked sensitivity to bee pollen composition. In addition, FT-Raman spectra indicated plant pigments as chemical markers of botanical origin. Furthermore, the fractionation of bee pollen was also performed, and composition of the fractions was characterized as well. The combination of imaging, spectroscopic, and statistical methods is a potent tool for bee pollen discrimination and thus may evaluate the quality and composition of this bee-keeping product.

• Klíčová slova
• bee pollen, color, discrimination, image analysis, spectroscopic methods,
• Publikační typ
• časopisecké články MeSH

The use of photosystem II (PSII) inhibitors allows simulating cascade of defense and damage responses, including the oxidative stress. In our study, PSII inhibiting herbicide metribuzin was applied to the leaf of the model plant species Chenopodium album. The temporally and spatially resolved cascade of defense responses was studied noninvasively at the leaf level by combining three imaging approaches: Raman spectroscopy as a principal method, corroborated by chlorophyll a fluorescence (ChlF) and infrared thermal imaging. ChlF imaging show time-dependent transport in acropetal direction through veins and increase of area affected by metribuzin and demonstrated the ability to distinguish between fast processes at the level of electron transport (1 - Vj) from slow processes at the level of non-photochemical energy dissipation (NPQ) or maximum efficiency of PSII photochemistry (Fv/Fm). The high-resolution resonance Raman images show zones of local increase of carotenoid signal 72 h after the herbicide application, surrounding the damaged tissue, which points to the activation of defense mechanisms. The shift in the carotenoid band indicates structural changes in carotenoids. Finally, the increase of leaf temperature in the region surrounding the spot of herbicide application and expanding in the direction to the leaf tip proves the metribuzin effect on slow stomata closure.

• Klíčová slova
• Raman mapping, carotenoids, oxidative stress, photoinhibition, photosynthesis, xanthophyll cycle, zeaxanthin,
• MeSH
• časové faktory MeSH
• Chenopodium fyziologie   MeSH
• chlorofyl a metabolismus   MeSH
• fluorescence MeSH
• fotosystém II (proteinový komplex) metabolismus   MeSH
• infračervené záření * MeSH
• listy rostlin metabolismus   MeSH
• optické zobrazování * MeSH
• počítačové zpracování signálu MeSH
• Ramanova spektroskopie * MeSH
• teplota * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chlorofyl a MeSH
• fotosystém II (proteinový komplex) MeSH