Withering is an important biological process accompanied by dehydration and cell wall metabolism in postharvest plant organs during curing/processing and storage. However, dynamics involved in cell wall metabolism and resultant water loss during withering in postharvest tobacco leaves is not well-documented. Here, tandem mass tag (TMT)-based quantitative proteomic analysis in postharvest tobacco leaves (cultivar K326) under different withering conditions was performed. In total, 11,556 proteins were detected, among which 496 differentially abundant proteins (DAPs) were identified. To elucidate the withering mechanism of tobacco leaves, 27 DAPs associated with cell wall metabolism were screened. In particular, pectin acetylesterases, glucan endo-1,3-beta-glucosidases, xyloglucan endotransglucosylase/hydrolase, alpha-xylosidase 1-like, probable galactinol-sucrose galactosyltransferases, endochitinase A, chitotriosidase-1-like and expansin were the key proteins responsible for the withering of postharvest tobacco leaves. These DAPs were mainly involved in pectin metabolism, cellulose, hemicellulose and galactose metabolism, amino sugar and nucleotide sugar metabolism as well as cell wall expansion. Furthermore, relative water content and softness values were significantly and positively correlated. Thus, dehydration and cell wall metabolism were crucial for tobacco leaf withering under different conditions. Nine candidate DAPs were confirmed by parallel reaction monitoring (PRM) technique. These results provide new insights into the withering mechanism underlying postharvest physiological regulatory networks in plants/crops.

萎凋是采后植物器官在腌制/加工和储存过程中伴随着脱水和细胞壁代谢的重要生物过程。然而，采后烟叶枯萎过程中细胞壁代谢和由此产生的水分损失所涉及的动态尚未得到充分记录。在这里，对不同萎凋条件下的采后烟叶（品种 K326）进行了基于串联质量标签（TMT）的定量蛋白质组学分析。总共检测到 11,556 个蛋白质，其中鉴定出 496 个差异丰度蛋白质（DAP）。为了阐明烟叶枯萎机制，筛选了27个与细胞壁代谢相关的DAP。特别是，果胶乙酰酯酶、葡聚糖内切 1,3-β-葡萄糖苷酶、木葡聚糖内切转葡糖基酶/水解酶、α-木糖苷酶 1 样、可能的半乳糖醇-蔗糖半乳糖基转移酶、内切几丁质酶 A、壳三糖苷酶 1 样和扩展蛋白是负责的关键蛋白质。用于采后烟叶的枯萎。这些DAP主要参与果胶代谢、纤维素、半纤维素和半乳糖代谢、氨基糖和核苷酸糖代谢以及细胞壁扩张。此外，相对含水量和柔软度值呈显着正相关。因此，脱水和细胞壁代谢对于不同条件下烟叶枯萎至关重要。通过平行反应监测（PRM）技术确认了九个候选DAP。这些结果为植物/农作物采后生理调节网络的枯萎机制提供了新的见解。