Role of phenylalanine ammonia-lyase in heat pretreatment-induced chilling tolerance in banana fruit

• Published in: Physiologia plantarum Vol. 132; no. 3; pp. 318 - 328
• Main Authors: Chen, Jian-ye, He, Li-hong, Jiang, Yue-ming, Wang, Yong, Joyce, Daryl C, Ji, Zuo-liang, Lu, Wang-jin
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.03.2008; Blackwell Publishing Ltd; Blackwell
• Subjects: Agronomy. Soil science and plant productions; antagonists & inhibitors; bananas; Base Sequence; Biological and medical sciences; chilling injury; Cold Temperature; cooling; DNA Primers; DNA Primers - genetics; drug effects; Economic plant physiology; Enzyme Inhibitors; Enzyme Inhibitors - pharmacology; enzymology; Fructification, ripening. Postharvest physiology; Fruit; Fruit - drug effects; Fruit - enzymology; Fruit - genetics; fruits; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes, Plant; genetics; Growth and development; heat; heat treatment; Hot Temperature; Indans; messenger RNA; metabolism; Musa; Musa - drug effects; Musa - enzymology; Musa - genetics; Organophosphonates; Organophosphonates - pharmacology; pharmacology; phenylalanine ammonia-lyase; Phenylalanine Ammonia-Lyase - antagonists & inhibitors; Phenylalanine Ammonia-Lyase - genetics; Phenylalanine Ammonia-Lyase - metabolism; plant stress; plant tissues; proteins; RNA, Messenger; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Plant; RNA, Plant - genetics; RNA, Plant - metabolism; storage temperature; Tolerance; Pretreatment; Cold; Fruit; Low temperature
• ISSN: 0031-9317; 1399-3054; 1399-3054
• DOI: 10.1111/j.1399-3054.2007.01013.x

Increasing evidence suggests that phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) is associated with low temperature stress in plant tissues. Banana fruit are highly susceptible to chilling injury. However, little is known about the role of PAL (i.e. gene expression, protein level and activity) in fruit chilling. In this work, the involvement of PAL induced by heat treatment (38°C for 3 days) prior to storage (8°C) in chilling tolerance was investigated. The PAL inhibitor 2-aminoindan-2-phosphonic acid (AIP) was also used to further study the role of PAL in the chilling tolerance. The results showed that mRNA transcripts (MaPAL1 and MaPAL2) and PAL protein levels increased during storage at chilling temperature. Heat treatment prior to storage alleviated chilling injury and enhanced PAL activity, protein amount and MaPAL1 and MaPAL2 transcript levels. The increases in parameters of PAL upon heat pretreatment were all inhibited by AIP treatment, which resulted in aggravation of chilling injury. Thus, these findings indicate that the induction of PAL by heat pretreatment was regulated at both the transcriptional and the translational levels and that PAL may play a role in heat pretreatment-induced chilling tolerance of banana fruit.