ROS Signalling in Plant Embryogenesis

Plant somatic embryogenesis is the ability of somatic and/or gametophytic cells to produce embryos capable of regenerating into viable plants. The expression of embryonic competence is manifested following precise manipulations of culture conditions often requiring applications of plant growth regulators and the imposition of stress conditions in the form of heat and/or cold treatments. Reactive oxygen species (ROS) are considered ubiquitous endogenous signals in plant systems, playing significant roles in a wide range of responses to environmental and endogenous factors. Accumulating evidence indicates that somatic embryogenesis is influenced by ROS. Although still partially unknown, the mechanisms underlying the cross talk between ROS and somatic embryogenesis have been investigated in a number of plant species. The focus of this chapter is to summarize information related to the role of ROS homeostasis and signalling on the induction and development of in vitro-produced embryos.