Effects Partial Solar Radiation on the Grapevine

Transcription

1 Effects Partial Solar Radiation on the Grapevine Johann Martinez-Luscher, Christopher Chen, Luca Brillante, Monica Cooper and S. Kaan Kurtural* Department of Viticulture and Enology

2 Flavonoids in grape berry Properties Color Co-pigmentation Astringency (tactile) Bitterness (taste) Health-promoting effects Important antioxidant capacity

3 Berry Anatomy Flesh (pulp) - juice - hydroxycinnamates Seed - tannins (bitter) - flavan-3-ols - hydroxybenzoic acids Skin - color pigments - tannins (astringent) - flavan-3-ols - flavonols Illustration by Jordan Koutroumanidis, Winetitles

4 Flavonoid biosynthesis Phenylalanine (phenyl propanoid pathway) Tannins

5 Constitution of flavonol and anthocyanin profiles 3 4 substituted 4 substituted substituted Shikimate eriodictyol narigenin pentahydroxyflavone F3H F3H F3H F3 H F3 5 H dihydroxyquercetin dihydroxykaempferol dihydroxymyricetin DFR leucocyanidin LDX cyanidin UFGT H cyanidin 3-o-glucoside FLS quercetin H MT isorhamnetin H FLS kaempferol H myricetin H MT laricitrin FLS C H 3 DFR leucodelphidin LDX delphidin UFGT delphidin 3-o-glucoside H + C H 3 MT I Glucose peonidin 3-o-glucoside H MT syringetin C H 3 C H 3 H MT + I Glucose MT H + petunidin 3-o-glucoside malvidin 3-o-glucoside C H 3 C H 3 F Glucose C H 3 Flavonols Anthocyanins H + I Glucose H + I Glucose C H 3 Abbreviations: F3 H: flavonoid 3 -hydroxylase; F3 5 H: flavonoid 3 5 -hydroxylase; FLS: flavonol synthase; DFR: dihydroflavonol reductase; LDX: leucocyanidin dioxygenase; UFGT: UDP-glucose flavonoid 3--glucosyltransferase; MT: -methyltransferase

6 Effect of water deficit on profiles 3 4 substituted Shikimate substituted eriodictyol narigenin pentahydroxyflavone F3H F3H F3H dihydroxyquercetin F3 H dihydroxykaempferol F3 5 H dihydroxymyricetin DFR leucocyanidin LDX cyanidin UFGT cyanidin 3-o-glucoside H FLS quercetin MT isorhamnetin H H FLS kaempferol H H FLS myricetin C H 3 MT laricitrin DFR leucodelphidin LDX delphidin UFGT delphidin 3-o-glucoside but flavonols? H + C H 3 MT I Glucose peonidin 3-o-glucoside H MT syringetin C H 3 C H 3 H MT + I Glucose MT H + petunidin 3-o-glucoside malvidin 3-o-glucoside C H 3 C H 3 F Glucose C H substituted predominate with water deficit as F3 5 H expression levels increase after veraison H + I Glucose H + I Glucose C H 3 Castellarin et al., 2007 (Planta; BMC Plant Biology; Plant Cell and Environment)

7 H A substituted substituted + C 2 3 H H B 6 4 H Anthocyanins Cyanidins F3 H Pelargonidins Uncommon in Vitis vinifera grapes 5 HH Delphidins F3 5 H Flavonol homologues Quercetins Kaempferols Myricetins

8 Flavonols impact on wine mouthfeel Ferrer-Gallego et al., 2016

9 Proanthocyanidins Important due to their astringent properties Role in long term color stability Grape based proanthocyanidins (+)-catechin (C) (-)-epicatechin (EC) (-)-epicatechin-3--gallate (ECG) (-)-epigallocatechin (EGC) Skin vs. seed proanthocyanidins Skins contain EGC Greater degree of polymerization Lower proportion of galloylated subunits 9 20/06/2017

10 How can we relate this information to tactile and taste sensation? Increase Tannin Molecular Size increase astringency/ chalky Sun et al, J. Agric. Food Chem. 2013, 61: Vidal et al, J Sci Food Agric. 2003, 83: Increase %ECG increase drying and chalkiness Vidal et al, J Sci Food Agric. 2003, 83: Increase %EGC lower coarseness Vidal et al, J Sci Food Agric. 2003, 83: Increase Color Incorporation less astringent Vidal et al, Analytica Chimica Acta. 2004, 513: 57-65

11 Varietal differences and effects of management practices Anthocyanin profile composition Effect of controlling vegetation Bobeica et al., 2015

12 Effect of water deficit on wine hue Cassasa et al., 2015

13 Changing environment in California Less cloud coverage, increasing temperatures Yield loss: Direct: Berry water content, shriveling Indirect: Acidity, astringency, color hue Shifts in: Phenology Compositional shifts in flavonoid profile 13 20/06/2017

14 ptimum light environment in the fruit zone during ripening Maximize diffuse or indirect sunlight within the canopy interior Minimize exposure of clusters to direct sunlight particularly in warm climates

15 B F C E D H A G

16 Radiation Effects on Whole Canopy Net Canopy Pn ( µmol C2/vine/s) % reflected 100% incident LLN#1 10 % transmitted LLN# PPFD (µmol/m 2 /s) LLN#3 1% transmitted Kurtural et al. 2003; Dami et al. 2005; Kurtural et al. 2005; % transmitted

17 Plant UV-B photoreception : UVR8 Heijde and Ulm 2013 Trends Plant Sci.

18 Experiment at akville Experiment Station Vineyard description Four year old producing vineyard CS clone 7/C3309. Spacing: 6 x 8, NW-SE orientation Bi-lateral cordon, relaxed vertical shoot-positioned training system Experimental design Five colored shade nets (and untreated control) Two applied water amounts Arranged factorially in a split-plot design with four blocks 18 20/06/2017

19 Colored shade nets Five polyethylene cloths with ~ 80% transmissivity of visible light Blue Pearl Aluminet Red Black Untreated control 19 20/06/2017

20 Applied water amounts Well watered (SDI): 65% of estimated ETc and applied to maintain a mid-day leaf water potential ψl of -1.2 MPa, from fruit set to harvest. Deficit watered (RDI): applied at the same ψl with SDI soon after bud break but was decreased to 25% ETc from fruit set to veraison with a ψl of -1.4 MPa and then reinstated to SDI from veraison until harvest /06/2017

21 RESULTS 21 20/06/2017

22 What do the these nets actually do? Transmittance of wavelengths by net color WL range % Tr Black % Tr White % Tr Silver % Tr Red % Tr Blue UV-B UV-A Violet Blue Green Yellow Red Far red Fr/R /20/2017

23 NE side (Morning exposed) 50 Physical conditions of the berry mol m -2 s pen field Control Blue Pearl Black Red Aluminet Temperature ( C) Solar radiation SW side (Evening exposed) Uncovered Shaded Ambient Temperature ( F) 1 0 Temperature ( C) Wavelength (nm) Temperature ( F) 23 6/20/ Uncovered Shaded Ambient 0 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 40

24 Components of yield Water applied Net Cover Berry Mass Cluster mass (g) Yield (kg/vine) (g Berry -1 ) SDI Control Blue Pearl Black Red Aluminet * RDI Control Blue Pearl Black Red Aluminet P (net) P (water) P (cnets x water) /20/2017

25 Berry composition 25 6/20/2017

26 Water applied Net Cover Berry Mass Total Anthocyanins Anth. Profile Hydroxylation TSS ph Titratable Acidity (g Berry -1 ) (mg Berry -1 ) 3'4'5'/3'4' (Brix ) (g L -1 ) SDI Control Blue Pearl Black Red Aluminet RDI Control Blue Pearl Black Red Aluminet In vines without nets (Control), well exposed berries did not make it to the end of the experiment! P (cloth) P (water) < P (cloth x water)

27 Kinetic development of anthocyanins 27 6/20/2017

28 UV-B and water deficit affected differently the anthocyanin groups Total skin anthocyanins Total skin anthocyanins (mg g -1 dry wt) 25 P (UV-B) =0.029 P (WA) = P (UV-BxWA) = Relative expression Gene expression one week after veraison P (UV-B) =0.020 P (WA) =0.624 P (UV-BxWA) =0.704 UFGT UFGT Cyanidins 3 4 substituted (mg g -1 dry wt) 3'4' substituted P (UV-B) =0.041 P (WA) <0.001 P (UV-BxWA) =0.634 Relative expression P (UV-B) =0.027 P (WA) =0.662 P (UV-BxWA) =0.480 F3 H F3'H Delphidins substituted (mg g -1 dry wt) 3'4'5' substituted P (UV-B) =0.059 P (WA) =0.005 P (UV-BxWA) =0.571 Relative expression P (UV-B) =0.863 P (WA) <0.001 P (UV-BxWA) =0.280 F3 5 H F3'5'H 0 kj m -2 d kj m -2 d kj m -2 d

29 Anthocyanin profile hydroxylation under higher light and water deficit Tot. Anth: 16.2 mg g -1 Cy: 21 % Dp: 79 % Tot. Anth : 13.6 mg g -1 Cy: 17 % Dp: 83 % Tot. Anth : 13.2 mg g -1 Cy: 9 % Dp: 91 % Tot. Anth : mg g -1 Cy: 10% Dp: 90 % Delphidin (molar %)

30 Water applied Net cover Skin mdp Seed mdp SDI Control Blue Pearl Black ** Red ** Aluminet RDI Control Blue ** Pearl Black Red Aluminet In vines without nets (Control), well exposed berries did not make it to the end of the experiment! P (nets) P (water) P (nets x water) /20/2017

31 How can we explain flavonol-anthocyanin profile behavior with transcript levels? Total flavonols Total anthocyanins Methylated Flavonols Methylated Anthocyanins Quercetins Cyanidins Methylated Flavonols Methylated Anthocyanins Delphidins Myricetins

32 Discussion Whereas moderate solar radiation exposure can equilibrate berry acidity and promote anthocyanin biosynthesis; extreme temperatures can lead to organic acids and anthocyanin degradation (Mori et al., 2007; Sweetman et al., 2014). In the present study, the 3.5 C reduction in temperature in the moment of highest berry temperature (i.e. 15:00 Hrs in the SW side) was associated with ameliorated berry composition. Greater anthocyanin content in berry Uncovered grapevines often displayed a greater level of proportion of berries with sunburn. 32 6/20/2017

33 So far based on 2016 results Primary metabolism: Yield reduction: Aluminet RDI irrigation treatment: Greater Brix accumulation Secondary metabolism: Hydroxylation of anthocyanins: Greater with Blue +RDI No measurable effect on skin mdp (tactile) Seed mdp > Control +RDI => Greater bitternes (taste) Seed mdp < Black, Red +SDI or Blue+RDI => Less bitterness (taste) 33 6/20/2017

34 Thank you for listening!