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Professor Brian Jordan Professor of Plant Biotechnology Agriculture and Life Sciences Faculty

The Effects of Ultraviolet Radiation and Canopy Shading on Grape Berry Biochemistry & Molecular Biology. Professor Brian Jordan Professor of Plant Biotechnology Agriculture and Life Sciences Faculty Lincoln University. Responses of Plants to Light. other organic compounds. Photosynthesis.

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Professor Brian Jordan Professor of Plant Biotechnology Agriculture and Life Sciences Faculty

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  1. The Effects of Ultraviolet Radiation and Canopy Shading on Grape Berry Biochemistry & Molecular Biology Professor Brian JordanProfessor of Plant Biotechnology Agriculture and Life Sciences Faculty Lincoln University

  2. Responses of Plants to Light other organic compounds Photosynthesis Sugars leaf growth stem growth germination, etc. Small amounts of light Light flowering dormancy plant habit, etc. Daily duration of light Information direction of growth Direction oflight

  3. Plants UV-B UV-A Blue Red & far red 0.7 0.6 0.5 0.4 Spectral irradiance (relative units) 0.3 0.2 0.1 0.0 300 400 500 600 700 800 900 1000 Wavelength (nm)

  4. PAR700nm – 380nm UV-A380-315nm UV-B315-280nm UV-C<280nm O3layer 100% 0% Earth’s surface Ultraviolet Penetration through the Stratospheric Ozone Layer

  5. Photoperception to gene expression Photoperception Signal Transduction Gene Expression

  6. UV-B Photoreceptor UV-B Specific Non-Specific Photoreceptor Via DNA damage Via ROS SignalTransduction Changes to gene expression

  7. Signal Transduction Pathways UV-B Peroxidase NADPH oxidase Receptor NOS ? Chloroplast signal, electron transport/ photophosphorylation O2- NO Ca2+/CaM H2O2 JA Ethylene Phosphorylation H2O2 SA Transcription factors Chs PDF1.2 PR genes Photosynthetic genes

  8. Role of UV/Light in Grape Development and Wine Quality • Effect on “ageing” of white wines in New Zealand • Changes to polyphenolic compounds • Changes to amino acids/protein content • Impact on aroma/flavour (methoxypyrazines) • Lipoxygenase as an example of molecular approach

  9. Vineyard experiments UVA+, UVB+ screen UVA+, UVB- screen UV- screen No frame No leaf removal, no frame UV+ UVA+ UV-

  10. UV-B Damage No UV-B Damage

  11. UV-absorbing compounds

  12. Amino Acid Metabolism and Implications for Wine Industry UV (and PAR) NITROGEN (Uptake and assimilation) AMINO ACIDS Cysteine, glutamate, glycine Valine, isoleucine, leucine All amino acids except proline Glutathione: implicated in the prevention of browning process Phenylalanine, tyrosine, tryptophan Methoxypyrazines: amino acids as precursors to flavour and aroma compounds Amino acid composition and implications for fermentation bouquet and yeast assimilable nitrogen Phenolics: amino acids as precursors – implicated in ageing and bitterness in white wine

  13. Amino Acid Composition Chardonnay Sauvignon blanc Glutamine Proline Arginine Alanine Serine Glutamate Arginine Proline Glutamine Alanine Threonine Serine Increasing Amounts

  14. Light regulation of nitrogen metabolism • Light regulates the conversion of glutamate into glutamine in the chloroplast • This involves the GOGAT pathway and requires ATP • This assimilation of nitrogen then provides amino acids/amines to the fruit Glutamate Glutamine

  15. Amino acids

  16. Amino acids

  17. 3-mercaptohexanol/3-mercaptohexanal acetate Tropical fruit and Citrus aromas Methoxypyrazines Green/green-pepper or capsicum aromas Major aroma chemicals

  18. Present Understanding: Synthesis of Thiol Precursors Changes during Must Fermentation Grape Metabolism through Berry Development and in Response to the Environment Lipids and Fatty Acids in Cell Membranes Release of Aroma Volatiles Primarily by Yeast Non Volatile s-cysteine Conjugate Precursor eg, s-3-(hexan-1-ol)-Glutathione 5/6Carbon Backbone LOXHPLetc GSTs Soft Berry at Harvest Hard Solid Berry VERAISON ‘Membrane Turnover’

  19. LOX-HPL pathway

  20. Phylogenetic analysis of grape LOXs and characterised LOXs from other plants L O L L 13-LOXs Type I L X 9-LOXs Type I O L O 1 O 1 1 1 X O d t X e X 1 A 1 r X S 1 L t P 1 C t L S 1 2 1 s N 1 t L C X X 1 X V 1 s 2 O 1 O O O L X v 2 L t X 1 O L L L O O A v a 1 X X L C V 1 1 1 G X 1 G L M X O m c m O X L 1 L 4 5 v O L V O L B X 1 X O P s L L 3 O X V v 1 C O X L G 1 L m O v X 3 H 1 1 G X m O 7 L L O X 1 3 G m m 6 Z 1 X O L 1 O s X 1 L O O L X 1 P s 2 L O X 1 Z m 1 1 A h 1 L O X 2 m G 1 X O L 2 L O X 6 Z m 1 m G 1 X O L O L X D V v Type II13-LOXs 2 t A 2 X O L L O X 2 A t 3 L O X 2 S t 2 L O X O V v L O X R L V L O O v X X 2 P A t V 4 v L O X I V v L O X H V v v V G X O L v v V F V X O L v E L V X O O A X L 2 X O O L v s L v O V 1 V X 1 K 2 J X t 1 Z L S O X d m O L L 2 2 o X O 1 O X 2 P d X L o O H 2 2 L P v L X O O 2 1 O X s X L 2 2 O A L t L 1 O X 2 B n 2

  21. SB berry expressed LOXs Relative expression of four berry expressed LOXs Proportional distribution of grape LOXs in different berry fractions

  22. Relative gene expressions of berry expressed LOXs during development

  23. Relative gene expressions of berry expressed LOXs during upon wounding

  24. Relative LOX gene expressions in SB berries infected with Botrytis I – berries with obvious signs of infection, NI – berries closely located to the infected, Control – healthy berries distantly located from the infected.

  25. pH effect on recombinant VvLOXA activity

  26. pH effect on recombinant VvLOXO activity

  27. Methoxypyrazines • Little is known about their biosynthesis • Thought to derive from amino acid biosynthesis • Accumulate up until veraison • Degrade after veraison and with exposure of grape bunches to light • At low concentrations (ng.L-1) contribute to green/green-pepper aromas

  28. UV responses & wine quality

  29. UV responses & wine quality +UV No leaf No No NoUV removal frame UV-B

  30. Effects of UV and Leaf Removal on Wine Quality • Methoxypyrazine levels low in juice at harvest, but high early in grape development: control of gene expression from amino acid precursors • Amino acid composition different in juice in response to light environment • Regulation of proline biosynthesis important for fermentation • Flavonoids accumulate with UV exposure: role of transcription factors • Lipoxygenase pathway: complex gene family and expression pattern

  31. Acknowledgements Grape Biotechnology and UV Research • Jason Wargent, Lancaster University, UK • Scott Gregan • Stephen Stilwell • Andriy Podolyan (Ph.D.) • Jim Shinkle, Trinity University, USA • Dr Rainer Hofmann • Dr Chris Winefield • Professor Brian Jordan (Programme Leader) Support From: • Foundation for Research, Science & Technology • NZ Royal Society/MoRST COST-ACTION 858 • Marlborough Wine Research Centre, Auckland University & Plant & Food Research • New Zealand Wine Industry • Lincoln University

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