UV screening by phenolics in berries of grapevine (Vitis vinifera)

2003 ◽  
Vol 30 (12) ◽  
pp. 1177 ◽  
Author(s):  
Christiane A. Kolb ◽  
Jiri Kopecký ◽  
Markus Riederer ◽  
Erhard E. Pfündel
Keyword(s):  
Vitis Vinifera ◽  
High Performance ◽  
Solar Spectrum ◽  
Outdoor Exposure ◽  
Hydroxycinnamic Acids ◽  
Vitis Vinifera L ◽  
Visible Radiation ◽  
Natural Radiation ◽  
Light Regimes

The role of phenolics in UV-screening was investigated in berries of a white grape cultivar (Vitis vinifera L. cv. Bacchus). Fluorescence microscopy revealed accumulation of phenolics in the skin of berries and, by high performance liquid chromatography and mass spectrometry, flavonols and hydroxycinnamic acids were identified as the main groups of UV-absorbing phenolics. Relationships between natural radiation and the synthesis of phenolics were studied in plants that were cultivated in the absence of UV radiation in a greenhouse before outdoor exposure to three different light regimes: the entire solar spectrum, the solar spectrum minus UV-B radiation and only visible radiation. During six days of exposure, flavonol synthesis was significantly stimulated by natural UV, in particular UV-B, but concentrations of hydroxycinnamic acids decreased under all conditions. Direct comparison of fluorimetrically-determined skin absorbance with absorbance of extracted flavonols or hydroxycinnamic acids suggested that acclimation of UV screening depends almost exclusively on flavonol synthesis. While increased flavonol levels resulted in efficient UV-A shielding, UV-B shielding was incomplete, probably due to decreased levels of the UV-B-absorbing hydroxycinnamic acids during exposure.

scholarly journals Effects of post-veraison irrigation on the phenolic composition of Vitis vinifera L. cv. ‘Xinomavro’ grapes

OENO One ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 173-189
Author(s):  
Seraphim Theocharis ◽  
Nikolaos Nikolaou ◽  
Eleftheria Zioziou ◽  
Maria Kyraleou ◽  
Stamatina Kallithraka ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
High Performance ◽  
Effective Means ◽  
High Performance Liquid Chromatographic ◽  
Vitis Vinifera L ◽  
Continuous Irrigation ◽  
Ultraviolet Absorbance ◽  
Absorbance Detection ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic

‘Xinomavro’ (the second planted red Greek variety behind ‘Agiorgitiko’) generally produces wines that are light in colour but with increased astringency, possibly related to grape flavonoid amount and composition; although irrigation is accepted as an effective means to enhance grape phenolic maturity, its role has not yet been sufficiently studied in the case of Xinomavro. This study aimed to determine the effect of post-veraison irrigation on berry anthocyanin and proanthocyanidin amount and composition, of field-grown Xinomavro vines (Vitis vinifera L.), under the typical summer conditions of Northern Greece. In a 10-year-old Xinomavro vineyard, two post-veraison watering regimes were applied—irrigation starting 20 days after veraison (mid-ripening irrigation, MRI) and irrigation starting immediately after veraison was completed (after veraison irrigation, AVI)—alongside non irrigated vines (NI), and vines irrigated continuously from berry set through harvest (continuous irrigation, CI). Proanthocyanidin composition was determined in both skins and seeds by employing phloroglucinolysis followed by HPLC-UV and MS detection (high-performance liquid chromatographic with tandem mass spectrometric and ultraviolet absorbance detection), and the anthocyanin profile was identified only in the skin extracts by HPLC-UV (high-performance liquid chromatographic with ultraviolet absorbance detection). Post-veraison irrigation increased yield parameters and reduced anthocyanin levels and the proportion of their stable forms (acylated vs. non-acylated, tri-oxygenated and methoxylated on the B-ring vs. di-oxygenated and hydroxylated), compared to NI vines; however, these effects were more pronounced in the case of early post-veraison irrigation (AVI) than late-season irrigation (MRI). Irrigation also increased the mean Degree of Polymerization (mDP) and prodelphinidin percentage of skin tannins and decreased mDP of seed tannins. In the light of the necessity to control the accelerated ripening under the increasingly hotter and drier climatic conditions, late irrigation (MRI) might provide a solution to avoid excessive sugar levels and allow a slightly higher yield without significant reductions in berry phenolic content. The results suggest that the optimisation of the timing of irrigation could provide an effective adaptation strategy to climate change in Mediterranean viticultural areas.

The Effect of Natural Soiling and Cleaning on the Size Distribution of Particles Deposited on Glass Mirrors

1980 ◽  
Vol 102 (4) ◽  
pp. 248-256 ◽  
Author(s):  
E. P. Roth ◽  
A. J. Anaya
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Diffuse Reflectance ◽  
Solar Spectrum ◽  
Outdoor Exposure ◽  
Size Distribution Function ◽  
Outdoor Environment ◽  
Size Distribution Of Particles

The particle size distribution and the reflectance properties of silvered glass mirrors exposed in an outdoor environment have been measured to determine the separate effects of natural soiling and natural cleaning (wind and rain). The wavelength dependent diffuse reflectance was correlated with the particle size distribution function for mirrors exposed to increasing periods of outdoor exposure. These measurements have indicated the significant role of small particles (radii ≲ 5 μm) in the soiling of exposed mirrors and in the subsequent reflectance loss over the solar spectrum.

scholarly journals (Z)-3-Hexenyl Butyrate Induces Stomata Closure and Ripening in Vitis vinifera

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1122
Author(s):  
Celia Payá ◽  
M. Pilar López-Gresa ◽  
Diego S. Intrigliolo ◽  
Ismael Rodrigo ◽  
José María Bellés ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Field Experiments ◽  
Negative Impact ◽  
Block Design ◽  
Stomatal Closure ◽  
Total Yield ◽  
Soluble Solids ◽  
Vitis Vinifera L ◽  
Randomized Block Design

Agronomy solutions for modifying pre-harvest grape ripening are needed for a more sustainable viticulture. Field experiments were performed in Vitis vinifera L. vines to study the effect of the previously described stomata-closing compound (Z)-3-hexenyl butyrate (HB). Exogenous treatments at different doses were periodically carried out using a randomized block design. Firstly, we observed that HB was able to induce stomatal closure in grapevine plants. Under field conditions, the application of HB around veraison induced a higher color intensity in berries, and vines treated at higher doses reached this stage earlier than the un-treated controls. There was also a clear increase in both grape anthocyanin concentration and total soluble solids without having a negative impact on total yield. We therefore, confirm the role of HB as a universal natural stomatal closure compound and propose a new use for HB in viticulture as a ripening inducer, by accelerating anthocyanin accumulation.

scholarly journals The Role of Strigolactones in the Regulation of Root System Architecture in Grapevine (Vitis vinifera L.) in Response to Root-Restriction Cultivation

2021 ◽  
Vol 22 (16) ◽  
pp. 8799 ◽  
Author(s):  
Yan Xu ◽  
Jiyuan Wang ◽  
Ruiqi Wang ◽  
Lei Wang ◽  
Caixi Zhang ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Root Architecture ◽  
Total Content ◽  
Root System Architecture ◽  
Root Diameter ◽  
Vitis Vinifera L ◽  
High Concentration ◽  
Expression Levels ◽  
Root Restriction

This study investigated the effects of root-restriction cultivation on the root architecture, endogenous strigolactone (SL) content, and SL-related genes expression in grapevine (Vitis vinifera L.). In addition, we clarified the effects of synthetic SL analog GR24 application on grapevine roots to explore the role of SLs in their development. The results showed that the root architecture changed significantly under root-restriction cultivation. At 40 days after transplantation (DAT), the contents of two types of SLs in roots under root restriction were both significantly lower than that in roots of the control. SL content was significantly positively correlated with the expression levels of VvCCD8 and VvD27, indicating that they play vital roles in SLs synthesis. After GR24 treatment for 20 days, the root length was significantly shorter than in the control. A low concentration (0.1 μM) of GR24 significantly reduced the root diameter and increased the fine-root density, while a high concentration (10 μM) of GR24 significantly reduced the lateral root (LR) length and increased the LR density. Concomitantly, GR24 (0.1 μM) reduced endogenous SL content. After GR24 treatment for 5 days, the total content of two tested SLs was highly positively correlated with the expression levels of VvDAD2, whereas it was highly negatively correlated with VvSMAXL4 at 20 days after GR24 treatment. This study helps to clarify the internal mechanism of root-restriction cultivation affecting the changes in grapevine root architecture, as well as further explore the important role of SLs in the growth of grapevine roots in response to root-restriction treatment.

PRELIMINARY OBSERVATIONS ON THE ROLE OF SIRTUIN GENES IN GRAPEVINE (VITIS VINIFERA L.) PHYSIOLOGY

2014 ◽  
pp. 363-369 ◽  
Author(s):  
M. Cucurachi ◽  
M. Busconi ◽  
C. Fogher ◽  
B. Hubbard ◽  
D.A. Sinclair ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Vitis Vinifera L

scholarly journals Comprehensive Chemical and Sensory Assessment of Wines Made from White Grapes of Vitis vinifera Cultivars Albillo Dorado and Montonera del Casar: A Comparative Study with Airén

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1282
Author(s):  
José Pérez-Navarro ◽  
Pedro Izquierdo-Cañas ◽  
Adela Mena-Morales ◽  
Juan Chacón-Vozmediano ◽  
Jesús Martínez-Gascueña ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Vitis Vinifera ◽  
High Performance ◽  
Gas Chromatography Mass Spectrometry ◽  
Vitis Vinifera L ◽  
Wine Aroma ◽  
Market Growth ◽  
Sensory Analyses ◽  
Broad Cross Section ◽  
Sensory Profiles

The ability to obtain different wines with a singular organoleptic profile is one of the main factors for the wine industry’s growth, in order to appeal to a broad cross section of consumers. Due to this, white wines made from the novel grape genotypes Albillo Dorado and Montonera del Casar (Vitis vinifera L.) were studied and compared to the well-known Airén at two consecutive years. Wines were evaluated by physicochemical, spectrophotometric, high-performance liquid chromatography–diode array detection–mass spectrometry, gas chromatography–mass spectrometry and sensory analyses. The chromatic characteristics of the new wines were defined by more color purity than Airén, with greenish highlights. In general, the phenolic profile of the Albillo Dorado wines showed a higher flavonol and hydroxycinnamic acid derivative content. Several volatile compounds were determined, and their odor activity values were calculated to determine their impact on wine aroma. A fruity series dominated the wine aromatic composition, but spicier and greener notes characterized the aroma profile of Airén wines. Albillo Dorado and Montonera del Casar were sensory evaluated as wines with a less fresh taste compared to Airén. Unique chemical and sensory profiles were determined for wines made from these novel grape genotypes, providing alternative monovarietal wines to encourage the wine market growth and extend the offer to consumers.

Optically-assessed preformed flavonoids and susceptibility of grapevine to Plasmopara viticola under different light regimes

2008 ◽  
Vol 35 (1) ◽  
pp. 77 ◽  
Author(s):  
Giovanni Agati ◽  
Zoran G. Cerovic ◽  
Anna Dalla Marta ◽  
Valentina Di Stefano ◽  
Patrizia Pinelli ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Large Scale ◽  
Plasmopara Viticola ◽  
Vitis Vinifera L ◽  
Infected Leaf ◽  
Light Regimes ◽  
Polyphenolic Content ◽  
Non Destructive ◽  
Large Scale Screening

The role of flavonoids in the response of plants to Plasmopara viticola, the phytopathogen agent of downy mildew, was studied in the Vitis vinifera L. cultivar Sangiovese. Grapevines in the vineyard were exposed to two light regimes, 100% and 35% of full sunlight in order to induce differences in total leaf polyphenolic content. Epidermal leaf phenolic compounds were assessed optically, using the Dualex chlorophyll fluorescence-based portable leaf-clip. Dualex data were calibrated by means of HPLC analysis of extracts from the same measured leaves. Good correlations were obtained with total flavonoid contents, which consist mainly of quercetin 3-O-glucuronide. From the Dualex non-destructive measurements, we showed that full-sun exposed leaves contained 75% more flavonoids than shaded leaves. Inoculation of leaves with P. viticola sporangia resulted in a significantly lower infected leaf area in sun-lit leaves compared with shaded ones, as seen from subsequent analysis of the downy mildew severity. These results indicated an inverse relationship between preformed flavonoids and the susceptibility of grapevines to downy mildew. The rapid optical method for the non-destructive assessment of flavonoids presented here could be useful for large scale screening and predicting V. vinifera susceptibility to P. viticola.

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