Song Huwei, Wang Xinfeng, Hu Weicheng, Yang Xianghui, Diao Enjie, Shen Ting, Qiang Qian
Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University, Huai'an 223300, Jiangsu, China; Huaian Key Laboratory of Food Components and Functional Foods, Huaiyin Normal University, Huai'an 223300, Jiangsu, China.
College of Horticulture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
Food Chem. 2017 Oct 1;232:434-442. doi: 10.1016/j.foodchem.2017.04.045. Epub 2017 Apr 7.
A novel peptidomics approach was used to discover cold-induced peptides in loquat fruit. Twenty unique peptides derived from 18 proproteins were identified, and they were involved in sugar signalling, protein metabolism and stress response. The quantitative analysis revealed 7 peptides with more than 2-fold upregulation, especially a 4.96-fold increase detected in the phytosulfokine (PSK) peptide. To further evaluate effects of PSK1 on fruit chilling tolerance, weight loss, firmness and internal browning were investigated in PSK1-treated loquat fruit at 0°C. By contrast, these chilling injury symptoms were effectively reduced by PSK1. PSK1 markedly delayed decreases of ATP content and energy charge. The PSK1-treated fruit exhibited significantly lower activities of cell-wall degrading enzymes and transcripts of genes related to lignin synthesis. Our results demonstrated that PSK1 improves chilling tolerance of loquat fruit by maintaining high energy status and cell integrity. Peptidomics analysis provides a promising tool to discover some key peptides.
一种新型的肽组学方法被用于发现枇杷果实中冷诱导的肽。从18种前体蛋白中鉴定出20种独特的肽，它们参与糖信号传导、蛋白质代谢和应激反应。定量分析显示7种肽上调超过2倍，尤其是植物磺肽素（PSK）肽增加了4.96倍。为了进一步评估PSK1对果实耐冷性的影响，在0°C下对经PSK1处理的枇杷果实的失重、硬度和内部褐变进行了研究。相比之下，PSK1有效减轻了这些冷害症状。PSK1显著延缓了ATP含量和能荷的下降。经PSK1处理的果实细胞壁降解酶活性和与木质素合成相关基因的转录本显著降低。我们的结果表明，PSK1通过维持高能量状态和细胞完整性来提高枇杷果实的耐冷性。肽组学分析为发现一些关键肽提供了一个有前景的工具。
