One of the aims of the VoF project is to investigate the effects of climate change on berry shrivel and berry cell death. Specifically due to predicted night-time temperatures increasing at a higher rate compared to diurnal temperatures, which might exacerbate this phenomena.
Cell death in winegrape berries may be a double-edged sword! It can be correlated with berry shrinkage but also related to flavour and sugar concentration. This article looks at shiraz, chardonnay and sultana berries, in terms of cell death and shrinkage.
Cell death occurs in pre-harvest berries of chardonnay and shiraz but not sultana. However, only shiraz consistently shrinks. This concentrates sugar and can lead to high alcohol wines. Shiraz is shown to be the ‘biggest loser’ in terms of weight loss but the flavour development and sugar concentration aspects are the other side of the double-edged sword.
Paper: Is the shiraz berry the biggest loser? The double-edged sword of cell death in winegrapes. Professor Steve Tyerman, Dr Sigfredo Fuentes, Dr Cassandra Collins and Dr Sue Bastian. August edition 2012 of Australian and New Zealand Grapegrower and Winemaker.
Figures:Cell death study using FDA (fluorescein diacetate). Images taken under microscope for Chardonnay, Shiraz and Sultana berries. Living tissue in mesocarp of berries corresponds to bright sections (fluorescence).