Response of rice (Oryza sativa) exposed to both biotic and abiotic stresses can be quantified by employing fast and accurate optical methods. In this study, the overall stress responses of (i) 12 near-isogenic lines (NILs) in the genetic background of the rice blast-susceptible cultivar Lijiangxintuanheigu (LTH) and (ii) four NILs in the genetic background of the bacterial blight-susceptible cultivar IR24, were inspected by means of Chl fluorescence (Chl-F) imaging. The distribution of the maximum and effective quantum yield of PSII (Fv/FM and QY) and steady-state Chl-F (Ft) were found to be effective in differentiating symptomatic leaf tissue for both rice blast and bacterial blight, which correlated well with 30 cycles of rice blast and six cycles of bacterial blight previously screened using classical (manual) approaches. Subsequently, identified Chl-F parameters allowing detection under ambient light (QY and Ft) were tested across both biotic and abiotic (drought) stress experiments, for rice cultivars contrasting for drought stress response (N22, IR64 and NSIC Rc 222). Their applicability has been proven for both rice blast and bacterial blight; however, QY failed to detect the effect of drought. In addition to Chl-F, the usefulness of 11 selected vegetation indices (Vis) was tested on these three cultivars exposed to particular stresses: (i) rice blast was detectable by Vis calculated from the visible spectrum; (ii) bacterial blight by near-infrared-related Vis; and (iii) drought by Vis calculated from the visible spectrum. The key Chl-F parameters and/or Vis have been summarized and discussed.
- MeSH
- chlorofyl chemie metabolismus MeSH
- fluorescence MeSH
- fluorometrie MeSH
- fotosystém II - proteinový komplex genetika metabolismus MeSH
- fyziologický stres * MeSH
- interakce hostitele a patogenu MeSH
- listy rostlin genetika metabolismus mikrobiologie MeSH
- Magnaporthe fyziologie MeSH
- nemoci rostlin genetika mikrobiologie MeSH
- období sucha * MeSH
- regulace genové exprese u rostlin MeSH
- rýže (rod) genetika metabolismus mikrobiologie MeSH
- spektrofotometrie MeSH
- Xanthomonas fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
Mature berries of Pinot Noir grapevines were sampled across a latitudinal gradient in Europe, from southern Spain to central Germany. Our aim was to study the influence of latitude-dependent environmental factors on the metabolite composition (mainly phenolic compounds) of berry skins. Solar radiation variables were positively correlated with flavonols and flavanonols and, to a lesser extent, with stilbenes and cinnamic acids. The daily means of global and erythematic UV solar radiation over long periods (bud break-veraison, bud break-harvest, and veraison-harvest), and the doses and daily means in shorter development periods (5-10 days before veraison and harvest) were the variables best correlated with the phenolic profile. The ratio between trihydroxylated and monohydroxylated flavonols, which was positively correlated with antioxidant capacity, was the berry skin variable best correlated with those radiation variables. Total flavanols and total anthocyanins did not show any correlation with radiation variables. Air temperature, degree days, rainfall, and aridity indices showed fewer correlations with metabolite contents than radiation. Moreover, the latter correlations were restricted to the period veraison-harvest, where radiation, temperature, and water availability variables were correlated, making it difficult to separate the possible individual effects of each type of variable. The data show that managing environmental factors, in particular global and UV radiation, through cultural practices during specific development periods, can be useful to promote the synthesis of valuable nutraceuticals and metabolites that influence wine quality.
- MeSH
- anthokyaniny analýza metabolismus MeSH
- ekosystém MeSH
- flavonoly analýza metabolismus MeSH
- nadmořská výška MeSH
- ovoce chemie růst a vývoj metabolismus účinky záření MeSH
- polyfenoly analýza metabolismus MeSH
- ultrafialové záření MeSH
- Vitis chemie růst a vývoj metabolismus účinky záření MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
A method for identification of highly fluorescent compounds in vine leaves infected by Plasmopara viticola was developed using reversed phase liquid chromatography with simultaneous diode array and fluorometric detection. Fluorescent compounds were extracted from leaves with a methanol-water mixture (70:30). Separation by HPLC was performed using a C(18) column and gradient elution with water-acetonitrile mixtures (20-80% of acetonitrile). The main unknown fluorescent compound was identified by line spectral comparison with a standard obtained by UV photoisomerization of trans-resveratrol glucoside, and its structure was confirmed by liquid chromatography-mass spectrometry. Identification and structural elucidation of the fluorescent compound in the leaves of Vitis vinifera allows early detection of Plasmopara viticola invasion.
- MeSH
- chromatografie kapalinová normy MeSH
- fenantreny chemie izolace a purifikace MeSH
- fluorescenční barviva chemie izolace a purifikace MeSH
- glukosidy chemie izolace a purifikace účinky záření MeSH
- hmotnostní spektrometrie normy MeSH
- isomerie MeSH
- listy rostlin chemie metabolismus mikrobiologie MeSH
- nemoci rostlin mikrobiologie MeSH
- Peronospora MeSH
- referenční standardy MeSH
- rostlinné extrakty chemie izolace a purifikace MeSH
- stilbeny chemie účinky záření MeSH
- ultrafialové záření MeSH
- Vitis chemie metabolismus mikrobiologie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We explored ability of reflectance vegetation indexes (VIs) related to chlorophyll fluorescence emission (R₆₈₆/R₆₃₀, R₇₄₀/R₈₀₀) and de-epoxidation state of xanthophyll cycle pigments (PRI, calculated as (R₅₃₁- R₅₇₀)/(R₅₃₁-R₅₇₀) to track changes in the CO₂ assimilation rate and Light Use Efficiency (LUE) in montane grassland and Norway spruce forest ecosystems, both at leaf and also canopy level. VIs were measured at two research plots using a ground-based high spatial/spectral resolution imaging spectroscopy technique. No significant relationship between VIs and leaf light-saturated CO₂ assimilation (A(MAX)) was detected in instantaneous measurements of grassland under steady-state irradiance conditions. Once the temporal dimension and daily irradiance variation were included into the experimental setup, statistically significant changes in VIs related to tested physiological parameters were revealed. ΔPRI and Δ(R₆₈₆/R₆₃₀) of grassland plant leaves under dark-to-full sunlight transition in the scale of minutes were significantly related to A(MAX) (R² = 0.51). In the daily course, the variation of VIs measured in one-hour intervals correlated well with the variation of Gross Primary Production (GPP), Net Ecosystem Exchange (NEE), and LUE estimated via the eddy-covariance flux tower. Statistical results were weaker in the case of the grassland ecosystem, with the strongest statistical relation of the index R₆₈₆/R₆₃₀ with NEE and GPP.
One of the elements showing strong beneficial effect on plants at low concentrations and toxic effects at higher concentrations is titanium (Ti). We investigated the interconnection between the Fe uptake and the Ti intoxication in model experiment on Fe-deficient spinach (Spinacia oleracea) plants to help to elucidate the mechanism of the biological activity of titanium in plants. The two different Ti (0 and 20 mg L⁻¹) and two different Fe (0 and 1.35 mg L⁻¹) concentrations in hydroponic medium were used in all four possible combinations. We compared chemical analysis of Ti and Fe in roots and shoots with the changes of the in vivo chlorophyll fluorescence. Although Fe and Ti concentration found in shoots of Ti-non-treated Fe-deficient plants was comparable with that in Ti-treated Fe-deficient plants, the soluble form of Ti present in the growth media had a negative effect on photosynthetic activity monitored by chlorophyll fluorescence measurements. The presence of Fe in growth medium significantly decreased the Ti concentration in shoots and increased the photosynthetic activity. Here, we propose that Ti affect components of electron transport chain containing Fe in their structure (particularly photosystem I) and decrease the photosystem II efficiency.
