title: Role of phenylalanine ammonia-lyase in heat pretreatment-induced chilling tolerance in banana fruit.
abstract: 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 degrees C for 3 days) prior to storage (8 degrees 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.
authors.affiliation: Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Jian-ye
authors.initials: JY
authors.lastname: Chen
authors.forename: Li-hong
authors.initials: LH
authors.lastname: He
authors.forename: Yue-ming
authors.initials: YM
authors.lastname: Jiang
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Daryl C
authors.initials: DC
authors.lastname: Joyce
authors.forename: Zuo-liang
authors.initials: ZL
authors.lastname: Ji
authors.forename: Wang-jin
authors.initials: WJ
authors.lastname: Lu
mesh_terms: D001483:Base Sequence; D003080:Cold Temperature; D017931:DNA Primers / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005638:Fruit / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D006358:Hot Temperature; D007189:Indans; D028521:Musa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D063065:Organophosphonates / Q000494:pharmacology; D010650:Phenylalanine Ammonia-Lyase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
chemical_list: C411146:2-aminoindan-2-phosphonic acid; D017931:DNA Primers; D004791:Enzyme Inhibitors; D007189:Indans; D063065:Organophosphonates; D012333:RNA, Messenger; D018749:RNA, Plant; D010650:Phenylalanine Ammonia-Lyase