The Relationship between Ethylene Binding and Dominant Insensitivity Conferred by Mutant Forms of the ETR1 Ethylene Receptor1
AUTOR(ES)
Hall, Anne E.
FONTE
American Society of Plant Physiologists
RESUMO
Ethylene responses in Arabidopsis are mediated by a small family of receptors, including the ETR1 gene product. Specific mutations in the N-terminal ethylene-binding domain of any family member lead to dominant ethylene insensitivity. To investigate the mechanism of ethylene insensitivity, we examined the effects of mutations on the ethylene-binding activity of the ETR1 protein expressed in yeast. The etr1-1 and etr1-4 mutations completely eliminated ethylene binding, while the etr1-3 mutation severely reduced binding. Additional site-directed mutations that disrupted ethylene binding in yeast also conferred dominant ethylene insensitivity when the mutated genes were transferred into wild-type Arabidopsis plants. By contrast, the etr1-2 mutation did not disrupt ethylene binding in yeast. These results indicate that dominant ethylene insensitivity may be conferred by mutations that disrupt ethylene binding or that uncouple ethylene binding from signal output by the receptor. Increased dosage of wild-type alleles in triploid lines led to the partial recovery of ethylene sensitivity, indicating that dominant ethylene insensitivity may involve either interactions between wild-type and mutant receptors or competition between mutant and wild-type receptors for downstream effectors.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=59379Documentos Relacionados
- Mutational Analysis of the Ethylene Receptor ETR1. Role of the Histidine Kinase Domain in Dominant Ethylene Insensitivity1
- Histidine kinase activity of the ETR1 ethylene receptor from Arabidopsis
- Effect of Ethylene Pathway Mutations upon Expression of the Ethylene Receptor ETR1 from Arabidopsis1
- Loss-of-Function Mutations in the Ethylene Receptor ETR1 Cause Enhanced Sensitivity and Exaggerated Response to Ethylene in Arabidopsis
- Association of the Arabidopsis CTR1 Raf-like kinase with the ETR1 and ERS ethylene receptors