Conservation of Ethylene Signaling Components in Other Plant Species
Genes that are similar to the Arabidopsis ethylene signaling components have been found in other plant species. For example, the tomato genome, like that of Arabidopsis, encodes a family of ethylene receptor genes, including Never-ripe, which are differentially expressed throughout development. The tomato ethylene receptor genes are homologous to ETR1. A tobacco homolog of EIN3 has been found, and genes similar to all the Arabidopsis signaling components can be found in the rice genomic sequence. These and other studies suggest that the components of these proteins probably represent ubiquitous mediators of ethylene signaling in plants.