Ethylene and Plant Immunity

Abstract

The phytohormone ethylene is implicated in diverse biological processes including resistance against pathogens. Ethylene production in plants is enhanced in response to pathogen infection. Activated ethylene signaling contributes positively or negatively to resistance depending on enemies and environmental conditions. In some cases, reported roles of ethylene during plant immunity are controversial. Although the core ethylene signal transduction pathway from the biosynthesis, perception to transcriptional response is well characterized, it is highly interconnected with other signaling pathways such as those mediated by the phytohormones salicylic acid and jasmonates. This fact could explain the complexity and controversy of findings. Recent advances using molecular genetics, genomics and computational approaches have started untangling the role of ethylene in the complex immune signaling net-work. In addition, ethylene is emerging as a key modulator of plant-microbe inter-actions beyond plant immunity. This chapter highlights the significance of and mechanisms underlying the ethylene signaling network in plant-microbe interactions. Keywords Botrytis-induced kinase 1 (BIK1) Á Ethylene Á Jasmonates (JA) Á Immune signaling network Á Map kinase (MAPK) Á Phytohormones Á Plant immunity Á Salicylic acid (SA)