ROS-talk – how the apoplast, the chloroplast, and the nucleus get the message through

Abstract

The production of reactive oxygen species (ROS) in different plant subcellular compartments is the hallmark of the response to many stress stimuli and developmental cues. The past two decades have seen a transition from regarding ROS as exclusively cytotoxic agents to being considered as reactive compounds which participate in elaborate signaling networks connecting various aspects of plant life. We have now arrived at a stage where it has become increasingly difficult to disregard the communication between different types and pools of ROS. Production of ROS in the extracellular space, the apoplast, can influence their generation in the chloroplast and both can regulate nuclear gene expression. In spite of existing information on these signaling events, we can still barely grasp the mechanisms of ROS signaling and communication between the organelles. In this review, we summarize evidence that supports the mutual influence of extracellular and chloroplastic ROS production on nuclear gene regulation and how this interaction might occur. We also reflect on how, and via which routes signals might reach the nucleus where they are ultimately integrated for transcriptional reprogramming. New ideas and approaches will be needed in the future to address the pressing questions of how ROS as signaling molecules can participate in the coordination of stress adaptation and development and how they are involved in the chatter of the organelles.

The ROS Wheel: Refining ROS Transcriptional Footprints

“…Previously reported meta-analyses, including ours, of oxidative stress-related transcriptional responses mainly described transcriptional changes specific to subcellular production site or chemical type, which are governed by a complex, yet to be elucidated mechanism (Gadjev et al, 2006;Shapiguzov et al, 2012;Vaahtera et al, 2014). Our meta-analysis shows that ROS transcriptional footprints are determined primarily by temporal aspects.…”

Inducible transgenic tobacco system to study the mechanisms underlying chlorosis mediated by the silencing of chloroplast heat shock protein 90

“…The generation of ROS in the chloroplasts depends on multiple aspects of chloroplast physiology including photosynthesis, gene expression, chlorophyll (tetrapyrrole) biosynthesis, and hormonal control [3]. Elevated ROS inside the chloroplast results in transcriptional reprogramming through identified and unknown components of the retrograde signaling but also through hormone signaling, e.g., increased production of SA [24,31]. Therefore, it is of great importance to quantify SA levels in the future study to analyze the molecular mechanisms underlying chlorosis mediated by the silencing of Hsp90C.…”

Effector Triggered Immunity: NLR Immune Perception and Downstream Defense Responses

“…ETI and the HR is associated with this prolonged phase of ROS production (Wojtaszek, 1997;Grant and Loake, 2000). Multiple organelles including chloroplasts, mitochondria, and peroxisomes contribute to ROS production during HR, and chloroplasts play a pivotal role in intracellular ROS production (Doyle et al, 2010;Shapiguzov et al, 2012). Intracellular ROS are not only involved in mediating cell death during the HR but also serve as signaling molecules to upregulate defense-related gene expression (Straus et al, 2010).…”