Chapter 20 - Interplays of Plant Circadian Clock and Abiotic Stress Response Networks

Abstract

Immotile organisms like plants have to deal with variable environmental stresses that trigger rhythmic biotic and abiotic stresses with the 24-h day–night cycle. Therefore, they have evolved internal mechanisms known as a circadian clock that modulates their sensitivity and response to various external stimuli, thus permitting them to screen all environmental transitions, in order to choose an appropriate at any given time. In this chapter, we focus on the interdependencies between the circadian clock components and the complex network of plant abiotic stress responses. There is increasing evidence that the clock regulates the stress response pathways by altering the perception of certain environmental signals in the process called gating, and conversely the rhythmic abiotic stress response has a significant influence on the circadian network. The connection between a particular alternative splicing event of the clock-associated genes and individual stress conditions, leading to the perturbations in the circadian clock operation and the plant abiotic stress tolerance, is discussed here. We summarize the crosstalk among the circadian clock and ABA-related responses. Finally, we consider the role of the clock in the regulation of plant metabolism, as well as the impact of the metabolic outputs on the circadian network.