Characterization of an ethylene receptor homologue from wheat and its expression during leaf senescence.

A wheat ethylene receptor homologue (W-er1) was isolated from a wheat stem cDNA library using the Arabidopsis ETR1 cDNA as a probe. The predicted amino acid sequence of W-er1 is over 70% similar to ERS1 from Arabidopsis and exhibits homology to bacterial two-component response regulators within the histidine kinase domain. Northern hybridization demonstrated that W-er1 was expressed in stem, leaf and root tissues. Treatments known to induce senescence of detached leaves including jasmonate, abscisic acid and wounding, increased the accumulation of W-er1 mRNA, while benzyladenine treatment did not. These data suggest that W-er1 may play a role in the process of leaf senescence.