ROS Are Good

Abstract

Reactive oxygen species (ROS) are thought to play a dual role in plant biology. They are required for many important signaling reactions, but are also toxic byproducts of aerobic metabolism. Recent studies revealed that ROS are necessary for the progression of several basic biological processes including cellular proliferation and differentiation. Moreover, cell death-that was previously thought to be the outcome of ROS directly killing cells by oxidation, in other words via oxidative stress-is now considered to be the result of ROS triggering a physiological or programmed pathway for cell death. This Opinion focuses on the possibility that ROS are beneficial to plants, supporting cellular proliferation, physiological function, and viability, and that maintaining a basal level of ROS in cells is essential for life.

Nanoparticles Alter Secondary Metabolism in Plants via ROS Burst

“…AgNPs triggered Ca 2+ and ROS signaling through the induction of Ca 2+ -permeable pores and direct oxidation of apoplastic L -ascorbic acid (Sosan et al, 2016). A. thaliana root hair defective 2 ( rhd2 ) mutant lacking NADPH oxidase RBOHC showed a significantly lower level of ROS generation in response to AgNPs compared with wild type plants (Sosan et al, 2016), indicating that the accumulation of ROS in cells is mediated by plasma membrane-bound NADPH oxidases (RBOH) enzymes that produce ROS at the apoplast (Mittler, 2017). On the other hand, chloroplastic ROS generation was observed in S. polyrhiza , based on the ability of AgNPs to inhibit Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity and the photo-protective capacity of PSII (Jiang et al, 2017).…”

“…As disruption of ROS homeostasis impairs plant growth and development, whereas maintenance of ROS levels within appropriate parameters promotes plant health (Mittler, 2017), it is emerging that the induction of antioxidant machinery by NPs might promote plant growth as reported in a few studies (Sharma et al, 2012; Burman et al, 2013; Kumar et al, 2013) as long as a harmful level of ROS is not reached in the cells, whereas, once breached, this may lead to impaired organelle function, membrane damage, and eventually phytotoxicity.…”

A Rice Glutamyl-tRNA Synthetase Modulates Early Anther Cell Division and Patterning

“…492 ROS exert dose-dependent impacts on cells. A lower or moderate basal level 493 of ROS is essential for cell proliferation and differentiation, but higher levels of 494 ROS is cytotoxic, causing cell damage and death (Mittler, 2017;Schieber and 495 H 2 O 2 is initially accumulated in the middle layer at stage 5; this may act as a 497 signal that triggers cell differentiation (Yang et al, 2016;Zhang and Yang, 498 2014). In this study, we observed the production of H 2 O 2 in osers1 anthers as 499 early as the formation of archesporial cells, which may cause over-proliferation 500 of anther cells and disorganized cell layers (Fig.…”

Redox Control of Aphid Resistance through Altered Cell Wall Composition and Nutritional Quality

“…Since the apoplast has few antioxidants, ROS are likely to have a longer lifetime in this compartment than they would have inside the cell Parsons and Fry, 2012;Noctor and Foyer, 2016). While the roles of ROS in the apoplast have been studied extensively in relation to fungal and bacterial pathogens (Mittler, 2017;Kimura et al, 2017), relatively little is known about the roles of apoplastic ascorbate and ascorbate oxidase (AO) in this process. Moreover, relatively few studies have concerned the role of oxidation of the apoplast in the plant response to aphid infestation.…”