Zamboni Anita, Minoia Leone, Ferrarini Alberto, Tornielli Giovanni Battista, Zago Elisa, Delledonne Massimo, Pezzotti Mario
Department for Sciences, Technologies and Markets of Grapevine and Wine, Via della Pieve 70, I-37029 San Floriano di Valpolicella (VR), Italy.
J Exp Bot. 2008;59(15):4145-59. doi: 10.1093/jxb/ern256. Epub 2008 Nov 13.
Post-harvest withering of grape berries is used in the production of dessert and fortified wines to alter must quality characteristics and increase the concentration of simple sugars. The molecular processes that occur during withering are poorly understood, so a detailed transcriptomic analysis of post-harvest grape berries was carried out by AFLP-transcriptional profiling analysis. This will help to elucidate the molecular mechanisms of berry withering and will provide an opportunity to select markers that can be used to follow the drying process and evaluate different drying techniques. AFLP-TP identified 699 withering-specific genes, 167 and 86 of which were unique to off-plant and on-plant withering, respectively. Although similar molecular events were revealed in both withering processes, it was apparent that off-plant withering induced a stronger dehydration stress response resulting in the high level expression of genes involved in stress protection mechanisms, such as dehydrin and osmolite accumulation. Genes involved in hexose metabolism and transport, cell wall composition, and secondary metabolism (particularly the phenolic and terpene compound pathways) were similarly regulated in both processes. This work provides the first comprehensive analysis of the molecular events underpinning post-harvest withering and could help to define markers for different withering processes.
葡萄浆果采后萎蔫用于甜酒和加强型葡萄酒的生产，以改变葡萄汁的品质特征并提高单糖浓度。人们对萎蔫过程中发生的分子过程了解甚少，因此通过AFLP转录谱分析对采后葡萄浆果进行了详细的转录组分析。这将有助于阐明浆果萎蔫的分子机制，并提供机会选择可用于跟踪干燥过程和评估不同干燥技术的标记物。AFLP-TP鉴定出699个萎蔫特异性基因，其中167个和86个分别是离体和植株上萎蔫所特有的。尽管在两个萎蔫过程中都发现了相似的分子事件，但很明显，离体萎蔫诱导了更强的脱水胁迫反应，导致参与胁迫保护机制的基因高表达，如脱水素和渗透溶质积累。参与己糖代谢和转运、细胞壁组成和次生代谢（特别是酚类和萜类化合物途径）的基因在两个过程中受到类似的调控。这项工作首次全面分析了采后萎蔫的分子事件，并有助于为不同的萎蔫过程确定标记物。
