ETR1-Specific Mutations Distinguish ETR1 from Other Arabidopsis Ethylene Receptors as Revealed by Genetic Interaction with RTE1

摘要

The plant growth regulator ethylene is perceived by a family of homologous receptors that negatively regu_late ethylene responses. It is well established that dominant missense mutations within the ethylene-binding domain of any of these receptors result in ethylene insensitivity (Chang et al., 1993; Hua et al., 1995, 1998; Wilkinson et al., 1995; Sakai et al., 1998; Hall et al., 1999; Wang et al., 2006). Furthermore, the deliberate introduction of such missense mutations is known to convert other ethylene receptor genes into dominant mutant forms that confer ethylene insensitivity (Hua et al., 1995, 1998; Hall et al., 1999; Terajima et al., 2001; Shaw et al., 2002; Cui et al., 2004). Here, we present a class of dominant mutations that does not fit this paradigm. That is, certain etrl ethylene-insensitive mutations in Arabidopsis (Arabidopsis thaliana) fail to confer ethylene insensitivity when introduced at identical positions in the closely related ERS1 ethylene receptor gene, despite the high level of sequence conservation between ERS1 and ETR1. What distinguishes these nontransferable dominant etrl mutations from the transferable ones is that the former are suppressed by mutations in RTE1, a gene that affects ETR1 signaling (Resnick et al., 2006, 2008).