Effect of cold storage and 1-MCP treatment on ethylene perception, signalling and synthesis: Influence on the development of the evergreen behaviour in ‘Conference’ pears

• Published in: Postharvest biology and technology 2013-12, Vol.86, p.212-220
• Main Authors: Chiriboga, Maria-Angeles, Saladié, Montserrat, Giné Bordonaba, Jordi, Recasens, Inmaculada, Garcia-Mas, Jordi, Larrigaudière, Christian
• Format: Article
• Language: English
• Subjects: ACC; ACO; ACS; Biological and medical sciences; Chilling; Ethylene receptors; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Gene expression
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2013.07.003

•The effect of cold storage and 1-MCP on ethylene perception and synthesis was investigated in ‘Conference’ pears.•1-MCP promoted PcETR1 and repressed PcACS1, PcACO1 gene expression and inhibited ACO activity during cold storage.•1-MCP up-regulated PcETR5, better maintained transcript levels of PcCTR1 and down-regulated ACS and ACO genes during shelf-life.•These regulations led to a complete inhibition of ripening and may explain the ‘evergreen’ behaviour in ‘Conference’ pears. To further understand the response of ‘Conference’ pears to 1-methylcyclopropene (1-MCP) treatment and their ability to restore ripening after prolonged periods of cold storage, fruit were treated with 0, 300nLL−1 1-MCP or 300nLL−1 exogenous ethylene plus 600nLL−1 1-MCP prior to storage. Changes in ethylene, ethylene precursors (ACC, MACC), ethylene-related enzyme activities (ACS, ACO) together with their transcript levels, and the expression of four ethylene receptors and one Raf kinase protein from the ethylene signalling pathway, were monitored before and after cold storage and during subsequent ripening at 20°C. 1-MCP treatment acted on the ethylene pathway in two differentiated phases. In a first initiation occurring during cold storage, the 1-MCP treatment limited the up-regulation of both PcACS1 and PcACO1 observed in control fruit and promoted an up-regulation of PcETR1 leading to a complete inhibition of ACO activity during cold storage. These regulations resulted in fruit unable to produce ethylene upon removal and promoted the second phase (maintenance phase). This second phase was characterized by a down-regulation of PcACS1 and PcACS4 as well as PcACO1 together with a clear up-regulation of PcETR5 and better maintenance of PcCTR1 transcript levels, which were partially reversed with exogenous ethylene treatment. All these different regulations led in turn to a complete inhibition of the ripening processes, which may partially explain the occurrence of the evergreen behaviour in ‘Conference’ pear during shelf-life.