Exogenous phytosulfokine α alleviates chilling injury of loquat fruit via regulating sugar, proline, polyamine and γ-aminobutyric acid metabolisms

• Published in: Food chemistry 2024-03, Vol.436, p.137729-137729, Article 137729
• Main Authors: Liu, Yu, Hou, Yuanyuan, Yi, Binghan, Zhao, Yaqin, Bao, Yinqiu, Wu, Zhengguo, Zheng, Yonghua, Jin, Peng
• Format: Article
• Language: English
• Subjects: Chilling injury; Loquat fruit; Phytosulfokine α; Polyamine and GABA; Proline; Sugar
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2023.137729

[Display omitted] •PSKα treatment mitigated chilling injury of loquat fruit during cold storage.•PSKα treatment could maintain high reducing sugar contents in loquat fruit.•PSKα treatment enhanced proline, PAs, and GABA contents in loquat fruit.•PSKα treatment promoted PSKα accumulation in loquat fruit. Postharvest loquat fruit is susceptible to chilling injury (CI) under cold stress. In this study, the effects of phytosulfokine α (PSKα) on sugar, proline, polyamine and γ-aminobutyric acid (GABA) metabolisms in loquat fruit during cold storage were investigated. The results showed that PSKα treatment significantly increased PSKα content along with up-regulating EjPSK3 and EjPSK6 expressions, and inhibited the increases of internal browning index, electrolyte leakage and malondialdehyde (MDA) content of loquat fruit. Besides, PSKα treatment maintained higher reducing sugar, proline, polyamines, and GABA contents in loquat fruit via activating biosynthesis pathway and suppressing catabolism pathway. More importantly, the results of correlation analysis indicated that PSKα content displayed positive correlations with reducing sugar, proline, polyamines and GABA contents. These findings suggested that the improved chilling tolerance in PSKα-treated loquat fruit was due to enhancing reducing sugar, proline, polyamines, and GABA contents, which might be modulated by endogenous PSKα signaling.