Genome-wide identification and role of HSFs in antioxidant response of hot water treated zucchini fruit during cold storage

• Published in: Plant physiology and biochemistry 2024-07, Vol.212, p.108743, Article 108743
• Main Authors: Bokhary, Syed Umar Farooq, Madebo, Miilion Paulos, Zhao, Yaqin, Ru, Xueyin, Bao, Yinqiu, You, Wanli, Zheng, Yonghua, Jin, Peng
• Format: Article
• Language: English
• Subjects: Antioxidants - metabolism; Chilling injury (CI); Chilling tolerance; Cold Temperature; CpHSFA4a; Cucurbita - genetics; Cucurbita - metabolism; Food Storage; Fruit - genetics; Fruit - metabolism; Gene Expression Regulation, Plant; Heat Shock Transcription Factors - genetics; Heat Shock Transcription Factors - metabolism; Hot Temperature; Plant Proteins - genetics; Plant Proteins - metabolism; Postharvest; Reactive oxygen species; Reactive Oxygen Species - metabolism; Water - metabolism
• ISSN: 0981-9428; 1873-2690; 1873-2690
• DOI: 10.1016/j.plaphy.2024.108743

Zucchini squashes are cold-sensitive and vulnerable to chilling injury (CI) resulting from reactive oxygen species (ROS) and hot water (HW) immersing effectively reduce CI symptoms during cold storage. However, mechanism involved in reduced ROS due to HW treatment has not been characterized well. In this study, tender green zucchini fruit were treated with HW for 15 min at 45 ± 1 °C and stored for 15 d at 4 ± 1 °C and above 90 % relative humidity. Results showed substantial reduction in CI index, electrolyte leakage, malonaldehyde (MDA) contents and ROS accumulation along with increased activity of ROS-scavenging enzymes due to HW treatment. To gain insight into the molecular mechanism involved in antioxidant defense system, transcriptomic analysis revealed that heat shock factors (HSF) accumulated due to HW treatment regulated the ROS pathway during cold stress. CpHSFA4a was one of the highly expressed transcription factors (TF) due to HW treatment that regulated the transcription of ROS enzymes related genes. CpHSFA4a bind actively with heat shock element (HSE) in promoter regions of CpSOD, CpCAT, CpAPX1, CpAPX2, and CpAPX3, activated and increased the expression of these genes. In conclusion, HW treatment alleviated the CI by maintaining ROS homeostasis through CpHSFA4a mediated ROS pathway in zucchini squashes during cold storage. •HW treatment alleviated CI and maintained post storage quality of zucchini squashes.•HW treatment induced the ROS signal transduction which in turn triggered the transcription of HSFs.•CpHSFA4a played a pivotal role in ROS homeostasis by transcriptional regulation of ROS related downstream genes.•HW treatment upregulated the enzymes related to ROS metabolism.