Reducing jasmonic acid levels causes ein2 mutants to become ethylene responsive.

It has previously been shown that jasmonic acid affects the ethylene signaling pathway. EIN2 is a central component of ethylene signaling that is downstream of the receptors. EIN2 has previously been shown to be required for ethylene responses. We found that reducing jasmonic acid levels, either mutationally or chemically, caused ein2 ethylene-insensitive mutants to become ethylene responsive. This effect was not seen with the ethylene-insensitive etr1-1 mutants that affect receptor function. Based upon these results, we propose a model where jasmonic acid is inhibiting ethylene signal transduction down-stream of the ethylene receptors. This may involve an EIN2-independent pathway.