The French Associates Institute for Agriculture and Biotechnology of Drylands, The Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boqer campus, Midreshet Ben Gurion, Israel.
College of Agriculture and Environmental Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
BMC Plant Biol. 2019 Feb 11;19(1):69. doi: 10.1186/s12870-019-1652-y.
Grape leaves provide the biochemical substrates for berry development. Thus, understanding the regulation of grapevine leaf metabolism can aid in discerning processes fundamental to fruit development and berry quality. Here, the temporal alterations in leaf metabolism in Merlot grapevine grown under sufficient irrigation and water deficit were monitored from veraison until harvest.
The vines mediated water stress gradually and involving multiple strategies: osmotic adjustment, transcript-metabolite alteration and leaf shedding. Initially stomatal conductance and leaf water potential showed a steep decrease together with the induction of stress related metabolism, e.g. up-regulation of proline and GABA metabolism and stress related sugars, and the down-regulation of developmental processes. Later, progressive soil drying was associated with an incremental contribution of Ca and sucrose to the osmotic adjustment concomitant with the initiation of leaf shedding. Last, towards harvest under progressive stress conditions following leaf shedding, incremental changes in leaf water potential were measured, while the magnitude of perturbation in leaf metabolism lessened.
The data present evidence that over time grapevine acclimation to water stress diversifies in temporal responses encompassing the alteration of central metabolism and gene expression, osmotic adjustments and reduction in leaf area. Together these processes mitigate leaf water stress and aid in maintaining the berry-ripening program.
葡萄叶为浆果发育提供生化底物。因此，了解葡萄叶片代谢的调控可以帮助我们了解对果实发育和浆果品质至关重要的过程。本研究从转色期到收获期监测了在充分灌溉和水分亏缺条件下生长的梅洛葡萄叶片代谢的时间变化。
葡萄藤逐渐介导水分胁迫，涉及多种策略：渗透调节、转录-代谢物改变和叶片脱落。最初，气孔导度和叶片水势急剧下降，同时诱导了与胁迫相关的代谢，如脯氨酸和 GABA 代谢以及与胁迫相关的糖的上调，以及发育过程的下调。后来，随着土壤逐渐干燥，钙和蔗糖对渗透调节的贡献逐渐增加，同时叶片开始脱落。最后，在叶片脱落并持续受到胁迫的情况下，收获前测量到叶片水势的增量变化，而叶片代谢的扰动幅度减小。
这些数据表明，随着时间的推移，葡萄对水分胁迫的适应在时间响应上存在差异，包括对中心代谢和基因表达、渗透调节以及叶片面积减少的改变。这些过程共同减轻叶片水分胁迫，有助于维持浆果成熟进程。
