Ethylene signal transduction and signaling roles-A Review

Abstract

The ethylene is a gaseous hormone which plays multiple roles in regulating plant growth and development andalso serves as a key modulator of the plant’s response to biotic or abiotic stresses. Its production is tightly regulated by internal signals during development and in response to environmental stimuli from biotic and abiotic stresses. Arabidopsis is a model plant to understand the ethylene signal transduction. In Arabidopsis, ethylene is perceived by a family of five receptors such as ETR1, ETR2, ERS1, ERS2 and EIN4 which are predominantly localized to the ER membrane. Ethylene receptor can be divided into two subfamilies i.e. type I and type II subfamilies, depending on the basis of structural similarities. CTR1 functions as a key mediator of ethylene signal transduction. Ethylene was originally regarded as a stress hormone because its synthesis is induced by a variety of environmental stress signals. Among the environmental stresses, such as ozone, wounding, and UV irradiation are the stimulationsfor ethylene synthesis. Enhanced ethylene production is an early, active response of plants to perception of pathogen attack and is associated with the induction of defence reactions. The elucidation of the mechanisms of ethylene signal transduction in response to biotic and abiotic stress is providing a framework for understanding how all plants sense and respond to ethylene.