Changes in water loss and cell wall metabolism during postharvest withering of tobacco (Nicotiana tabacum L.) leaves using tandem mass tag-based quantitative proteomics approach

• Published in: Plant physiology and biochemistry 2020-05, Vol.150, p.121-132
• Main Authors: Wu, Shengjiang, Cao, Gaoyi, Adil, Muhammad Faheem, Tu, Yonggao, Wang, Wei, Cai, Bin, Zhao, Degang, Shamsi, Imran Haider
• Format: Article
• Language: English
• Subjects: Cell Wall - metabolism; Dehydration; Gene Expression Regulation, Plant; Nicotiana - metabolism; Plant Leaves - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Postharvest tobacco leaves; Proteomics; TMT-Based quantitative proteomics; Water - metabolism; Withering
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2020.02.040

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. •Withering is an important biological process accompanied by intricate cell wall metabolism and water loss during curing.•In total, 496 DAPs were identified and of which 27 DAPs were found to be involved in cell wall metabolism.•14 DAPs were involved in pectin, cellulose/hemicellulose, galactose, nucleotide sugar metabolism and cell wall expansion.•Relative water content and softness values were significantly correlated.