In grape berries, sugar and potassium (K+) accumulation slows from the mid-ripening stage, and is eventually complete when berries are fully ripe1. Mesocarp cells die within the central region of Shiraz berries at the late ripening stage2. It has been hypothesised that hypoxia may be a contributing factor to berry cell death3, decreasing respiration and the berry energy status. Membranes of cells with high vitality may be better energised by H+ pumps, generating electric potentials across membranes. The resulting voltage could regulate various K+ transporters and channels. To characterise berry energy status theoretically associated with cell vitality and K+ accumulation, we measured trans-membrane voltage (Vm) and trans-tissue voltage (Vt) in Shiraz berries. Vm and Vt of berries increased in verasion, followed by a subsequent declining. The Vm values were unevenly distributed between berry compartments, and the Vm profile in earlier ripening stages may be associated with oxygen distribution. The expression levels of genes associated with K+ transport, membrane energisation and berry cell death were analysed in Shiraz pericarps at verasion, mid-ripening and late-ripening stages. Four clusters of genes were distinguished by different patterns of expression change, indicating the complexity of K+ transport regulation in ripening berries under energy limitation. The outcome of this study may be beneficial to improve viticulture strategy and manage berry composition.
|Publication status||Published - 26 Jun 2022|
|Event||18th Australian Wine Industry Technical Conference and Trade Exhibition - Adelaide Convention Centre, Adelaide, Australia|
Duration: 26 Jun 2022 → 29 Jun 2022
https://awitc.com.au/ (Conference webpage)
https://awitc.com.au/conference-program/ (Conference program)
|Conference||18th Australian Wine Industry Technical Conference and Trade Exhibition|
|Period||26/06/22 → 29/06/22|
|Other||The Australian Wine Industry Technical Conference is the premier technical event for the Australian wine industry. Held every three years since 1970, it combines an extensive program of plenary sessions, workshops, posters, student forum and social events with the industry’s most respected and extensive trade exhibition.|
The Australian Wine Industry Technical Conference Inc. has two members: The Australian Wine Research Institute and the Australian Society of Viticulture and Oenology.