Abstract
Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d. Different light regimes were produced by filters transmitting natural radiation, or screening out the UV-B (280–315 nm), or screening out the UV-A (315–400 nm) and the UV-B spectral range. During exposure, synthesis of UV-screening phenolics in leaves was quantified using HPLC: All treatments increased concentrations of hydroxycinnamic acids but the rise was highest, reaching 230% of the initial value, when UV radiation was absent. In contrast, UV-B radiation specifically increased flavonoid concentrations resulting in more than a 10-fold increase. Transmittance in the UV of all extracted phenolics was lower than epidermal UV transmittance determined fluorimetrically, and the two parameters were curvilinearly related. It is suggested that curvilinearity results from different absorption properties of the homogeneously dissolved phenolics in extracts and of the non-homogeneous distribution of phenolics in the epidermis. UV-B-dependent inhibition of maximum photochemical yield of photosystem II (PSII), measured as variable fluorescence of dark-adapted leaves, recovered in parallel to the buildup of epidermal screening for UV-B radiation, suggesting that PSII is protected against UV-B damage by epidermal screening. However, UV-B inhibition of CO2assimilation rates was not diminished by efficient UV-B screening. We propose that protection of UV-B inactivation of PSII is observed because preceding damage is efficiently repaired while those factors determining UV-B inhibition of CO2 assimilation recover more slowly.
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Claims 11
Claim · model-written summary
All light treatments increased hydroxycinnamic acid concentrations in grape leaves during exposure.
- Taxon
- Vitis vinifera
Vitis viniferae0 - Material
- Silvanere0
- Organ / stage
- leavese1
- Treatment
- three different light regimese0
- Compound
- hydroxycinnamic acidse2
- Outcome
- concentrations of hydroxycinnamic acidse2
- Direction
- increasede2
- Comparator
- initial valuee2
- Setting
- greenhousee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e1“During exposure, synthesis of UV-screening phenolics in leaves was quantified using HPLC”
e2“All treatments increased concentrations of hydroxycinnamic acids but the rise was highest, reaching 230% of the initial value, when UV radiation was absent”
Claim · model-written summary
Hydroxycinnamic acid concentrations rose highest, to 230% of the initial value, when UV radiation was absent.
- Taxon
- Vitis viniferaVitis viniferae0
- Material
- Silvanere0
- Organ / stage
- leavese1
- Treatment
- UV radiation was absente2
- Compound
- hydroxycinnamic acidse2
- Outcome
- concentrations of hydroxycinnamic acidse2
- Direction
- higheste2
- Value
- 230%e2
- Comparator
- initial valuee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e1“During exposure, synthesis of UV-screening phenolics in leaves was quantified using HPLC”
e2“All treatments increased concentrations of hydroxycinnamic acids but the rise was highest, reaching 230% of the initial value, when UV radiation was absent”
Claim · model-written summary
UV-B radiation specifically increased flavonoid concentrations in grape leaves by more than 10-fold.
- Taxon
- Vitis viniferaVitis viniferae0
- Material
- Silvanere0
- Organ / stage
- leavese1
- Treatment
- UV-B radiatione3
- Compound
- flavonoide3
- Outcome
- flavonoid concentrationse3
- Direction
- increasede3
- Value
- more than a 10-fold increasee3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e1“During exposure, synthesis of UV-screening phenolics in leaves was quantified using HPLC”
e3“In contrast, UV-B radiation specifically increased flavonoid concentrations resulting in more than a 10-fold increase”
Claim · model-written summary
UV transmittance of extracted phenolics was lower than epidermal UV transmittance.
- Taxon
- Vitis viniferaVitis viniferae0
- Compound
- phenolicse4
- Outcome
- Transmittance in the UV of all extracted phenolicse4
- Direction
- lowere4
- Comparator
- epidermal UV transmittancee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e4“Transmittance in the UV of all extracted phenolics was lower than epidermal UV transmittance determined fluorimetrically, and the two parameters were curvilinearly related”
Claim · model-written summary
UV transmittance of extracted phenolics and epidermal UV transmittance were curvilinearly related.
- Taxon
- Vitis viniferaVitis viniferae0
- Compound
- phenolicse4
- Outcome
- curvilinearly relatede4
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e4“Transmittance in the UV of all extracted phenolics was lower than epidermal UV transmittance determined fluorimetrically, and the two parameters were curvilinearly related”
Claim · model-written summary
Curvilinearity between the two transmittance measures is suggested to result from different absorption properties of dissolved extracts and the non-homogeneous epidermal distribution of phenolics.
- Taxon
- Vitis viniferaVitis viniferae0
- Compound
- phenolicse5
- Outcome
- curvilinearitye5
- Qualifier
- different absorption properties of the homogeneously dissolved phenolics in extracts and of the non-homogeneous distribution of phenolics in the epidermise5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e5“It is suggested that curvilinearity results from different absorption properties of the homogeneously dissolved phenolics in extracts and of the non-homogeneous distribution of phenolics in the epidermis”
Claim · model-written summary
UV-B-dependent inhibition of maximum photochemical yield of PSII recovered in parallel to the buildup of epidermal screening against UV-B.
- Taxon
- Vitis viniferaVitis viniferae0
- Organ / stage
- dark-adapted leavese6
- Treatment
- UV-B radiatione6
- Outcome
- maximum photochemical yield of photosystem II (PSII)e6
- Direction
- recoverede6
- Qualifier
- in parallel to the buildup of epidermal screeninge6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e6“UV-B-dependent inhibition of maximum photochemical yield of photosystem II (PSII), measured as variable fluorescence of dark-adapted leaves, recovered in parallel to the buildup of epidermal screening for UV-B radiation, suggesting that PSII is protected against UV-B damage by epidermal screening”
Claim · model-written summary
PSII is suggested to be protected against UV-B damage by epidermal screening.
- Taxon
- Vitis viniferaVitis viniferae0
- Outcome
- PSII is protected against UV-B damagee6
- Qualifier
- by epidermal screeninge6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e6“UV-B-dependent inhibition of maximum photochemical yield of photosystem II (PSII), measured as variable fluorescence of dark-adapted leaves, recovered in parallel to the buildup of epidermal screening for UV-B radiation, suggesting that PSII is protected against UV-B damage by epidermal screening”
Claim · model-written summary
UV-B inhibition of CO2 assimilation rates was not diminished by efficient UV-B screening.
- Taxon
- Vitis viniferaVitis viniferae0
- Treatment
- efficient UV-B screeninge7
- Outcome
- UV-B inhibition of CO2assimilation ratese7
- Direction
- not diminishede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e7“However, UV-B inhibition of CO2assimilation rates was not diminished by efficient UV-B screening. We propose that protection of UV-B inactivation of PSII is observed because preceding damage is efficiently repaired while those factors determining UV-B inhibition of CO2 assimilation recover more slowly”
Claim · model-written summary
Protection of PSII against UV-B inactivation is suggested to occur because preceding damage is efficiently repaired.
- Taxon
- Vitis viniferaVitis viniferae0
- Outcome
- protection of UV-B inactivation of PSIIe7
- Qualifier
- preceding damage is efficiently repairede7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e7“However, UV-B inhibition of CO2assimilation rates was not diminished by efficient UV-B screening. We propose that protection of UV-B inactivation of PSII is observed because preceding damage is efficiently repaired while those factors determining UV-B inhibition of CO2 assimilation recover more slowly”
Claim · model-written summary
Factors determining UV-B inhibition of CO2 assimilation are suggested to recover more slowly.
- Taxon
- Vitis viniferaVitis viniferae0
- Outcome
- those factors determining UV-B inhibition of CO2 assimilatione7
- Qualifier
- recover more slowlye7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grape (Vitis vinifera cv Silvaner) vine plants were cultivated under shaded conditions in the absence of ultraviolet (UV) radiation in a greenhouse, and subsequently placed outdoors under three different light regimes for 7 d”
e7“However, UV-B inhibition of CO2assimilation rates was not diminished by efficient UV-B screening. We propose that protection of UV-B inactivation of PSII is observed because preceding damage is efficiently repaired while those factors determining UV-B inhibition of CO2 assimilation recover more slowly”