Transcriptomic Analysis on the Regulation of Tomato Ripening by the Ethylene Inhibitor 1-methylcyclopropene

Tomato is a climacteric fruit whose ripening is regulated by the plant hormone ethylene. 1-methylcyclopropene (1-MCP) is a competitive ethylene inhibitor that can delay the fruit ripening process. To understand the molecular mechanism of how 1-MCP inhibits tomato fruit ripening, transcriptomics (RNA-Seq) was used to identify genes that were differentially expressed in 1-MCP-treated (Day 1) tomato fruits. Of the 35340 genes in the tomato genome, about 50% were expressed with 1-MCP treatment. There were 5683 genes identified as significantly differentially expressed. Quantitative reverse transcription PCR (qRT-PCR) assays were used to validate the RNA-Seq data. Our results showed that 1-MCP treatment resulted in the down-regulation of fruit ripening-related genes, including genes involved in ethylene synthesis, signal transduction and carotenoid biosynthesis. Our results provide insight at the whole genome level regarding gene regulation by 1-MCP during fruit ripening. Understanding the molecular basis of 1-MCP inhibition on tomato ripening may help farmers and food processors to better use 1-MCP in agriculture and food industry.