Roles of Ethylene in Plant Growth and Responses to Stresses

Abstract

Ethylene regulates many aspects of plant growth and development and responses to multiple biotic and abiotic stresses. The regulatory mechanisms of ethylene have been extensively studied during the past two decades. Ethylene is synthesized via a simple linear pathway, in which ACC synthase and ACC oxidase function as key enzymes. Ethylene biosynthesis is tightly controlled in response to various internal and external signals. A linear signaling pathway has been established on the basis of characterization of triple response mutants in Arabidopsis. Ethylene signal is perceived by a family of membrane-bound receptors and is transmitted by CTR1 and EIN2 and is then amplified through EIN3 and ERF transcription cascades. Ethylene interacts with other phytohormones in most developmental process. Biotechnological manipulation of ethylene actions at the level of biosynthesis, perception, and signal transduction has been successfully achieved in a number of plant species, especially crops. This chapter summarizes the recent advances in ethylene biosynthesis and its regulation, ethylene signal transduction, regulatory roles of ethylene in plant development and abiotic stress responses, cross talk with other hormones, and biotechnological applications in agriculture.