Ethylene signaling pathway is not linear, however its lateral part is responsible for sensing and signaling of sulfur status in plants.

A secondary, non-linear, lateral part of ethylene signaling pathway has been anticipated and speculated before. Recently, it has been found that part of the proteomic response of Eruca sativa to silver nitrate (which is an inhibitor of ethylene signaling) is related to sulfur metabolism. Using public Arabidopsis thaliana microarray data, I show that silver nitrate mimics the signal of sulfur starvation at the transcriptome level. This, combined with data mined from literature, indicates that ethylene receptors are localized at the beginning of the response to sulfur deficiency in plants. This means that the non-linear, lateral part of ethylene signaling pathway exists and is responsible for transduction of the signal of sulfur deficit. Here, I present a model of such a pathway and anticipate it to be the starting point for more detailed analysis of the lateral part of ethylene signaling pathway and the exact mechanism of sulfur status sensing in plants.