Global transcriptome profiling analysis of ethylene-auxin interaction during tomato fruit ripening

Auxin-ethylene interactions are crucial for fruit ripening processes. However, the molecular basis of the regulatory network of auxin-ethylene interaction during ripening is still not very clear. To reveal the potential molecular mechanism of ethylene-auxin interplay in tomato (Solanum lycopersicum L.) fruit ripening, global transcriptome profiling analysis was performed on cherry tomato fruit treated with auxin, ethylene or the combination of the two hormones. The results showed that ethylene modulated auxin transport, metabolism and signaling processes by affecting the expression patterns of genes encoding auxin carrier proteins, aldehyde dehydrogenase and primary auxin-responsive proteins. Most genes involved in ethylene biosynthesis and signaling were regulated 7 days after treatment with exogenous auxin. Furthermore, the expression levels of mitogen-activated protein kinase (MAPK) and of ubiquitination-related genes were altered in auxin-treated fruit, suggesting that auxin regulates ethylene metabolism and signaling via complicated mechanisms. The potential interaction points in auxin-ethylene crosstalk were also identified and a model was proposed. Our analyses provide a global insight into the ethylene-auxin interaction and predict the potential regulators in the crosstalk of the two hormones during the fruit ripening process.