Project name: Prunus persica

Description: Peach is a climacteric fruit whose ripening is largely dependent on ethylene. Recently, it has been shown that auxin is able to autonomously regulate the expression of ripening related genes, and that a cross-talk between ethylene and auxin occurs during the ripening process.By using the non-destructing index of absorbance difference (IAD), mature nectarines were homogeneously grouped into three classes (0, 1 and 2) according to their ripening phase and treated with 1-methylcyclopropene (1-MCP), known to block ethylene receptors. 1-MCP responses differed in the three classes that were thus used to molecularly investigate the auxin-ethylene cross-talk during the transition from maturation to ripening and the accompanying switch of ethylene biosynthesis from System-1 to System-2. Microarray experiments showed that 1-MCP modified the expression of 121 genes (63 were up-regulated and 59 down-regulated). Besides inducing ethylene-, auxin- and ripening-repressed genes and repressing ethylene-, auxin- and ripening-induced genes, also genes induced by ripening, auxin and 1-MCP were discovered. The up-regulating effect of 1-MCP was observed for ctg134, similar to signalling peptides, for 1-aminocyclopropane-1-carboxylic acid synthase 1 (ACS1) and, interestingly, for many auxin-regulated genes, such as GH3, whose expression is widely used as a marker for free auxin. The latter finding, together with the induction of an IAA amidohydrolase, suggests that the 1-MCP application could have caused a rise in free auxin, thus leading to an increase in ethylene biosynthesis through the induction of the tightly regulated ACS1 gene.Overall design: A "direct comparison" approach has been used to investigate the effect at the transcriptional level of 1-methylcyclopropene (1-MCP) on preclimacteric nectarine (Prunus persica cv Stark Red Gold) fruit.RNA has been extracted from either 1-MCP treated fruit or from fruit kept in air (control).Four hybridization have been conducted for a total of four technical replicates (with dye-swap).

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Agricultural

Release date: 2010-04-01

Last updated: 2009-05-26