ROS Production and Scavenging under Anoxia and Re-Oxygenation in Arabidopsis Cells: A Balance between Redox Signaling and Impairment

Abstract

Plants can frequently experience low oxygen concentrations due to environmental factors such as flooding or waterlogging. It has been reported that both anoxia and the transition from anoxia to re-oxygenation determine a strong imbalance in the cellular redox state involving the production of reactive oxygen species (ROS) and nitric oxide (NO). Plant cell cultures can be a suitable system to study the response to oxygen deprivation stress since a close control of physicochemical parameters is available when using bioreactors. For this purpose, Arabidopsis cell suspension cultures grown in a stirred bioreactor were subjected to a severe anoxic stress and analyzed during anoxia and re-oxygenation for alteration in ROS and NO as well as in antioxidant enzymes and metabolites. The results obtained by confocal microscopy showed the dramatic increase of ROS, H2O2, and NO during the anoxic shock. All the ascorbate-glutathione related parameters were altered during anoxia but restored during re-oxygenation. Anoxia also induced a slight but significant increase of α-tocopherol levels measured at the end of the treatment. Overall, the evaluation of cell defenses during anoxia and re-oxygenation in Arabidopsis cell cultures revealed that the immediate response involving the overproduction of reactive species activated the antioxidant machinery including ascorbate-glutathione system, α-tocopherol and the ROS-scavenging enzymes ascorbate peroxidase, catalase, and peroxidase making cells able to counteract the stress toward cell survival.

RNA-Seq reveals novel genes and pathways associated with hypoxia duration and tolerance in tomato root

“…The induction of NO after hypoxia in the root occurs rapidly, within minutes, and therefore it has been suggested to be involved in hypoxic stress response in the root 53 . Some of the functions, which have been attributed to hypoxia-induced NO, include a role in the production of ATP 54 , interaction with alternative oxidase (AOX) 55,56 and programmed cell death (PCD) during aerenchyma formation 31,57 . Wany et al (2017) have shown that NO, in addition to ROS, is involved in programmed cell death during ethylene-induced lysigenous aerenchyma formation under hypoxic stress in wheat roots.…”

Signal Dynamics and Interactions during Flooding Stress

“…However, several studies report increased ROS accumulation under hypoxia/anoxia ( Fig. 1; Chang et al, 2012;Pucciariello et al, 2012;Paradiso et al, 2016). Under oxygen deprivation, ROS production likely still occurs in the mitochondria, chloroplasts, and peroxisomes.…”

Group VII Ethylene Response Factors in Arabidopsis: Regulation and Physiological Roles

“…Thus, the same protective mechanisms can act as an integral part of the ERF-VII dependent response strategy to hypoxia. Improved ROS management has been associated with superior submergence tolerance in maize and Brachypodion distachyon (Campbell et al, 2015;Rivera-Contreras et al, 2016), while the activation of antioxidant responses in the posthypoxic phase is crucial for survival in Arabidopsis (Paradiso et al, 2016;Yuan et al, 2017). Interestingly, a target of RAP-type ERF-VIIs, namely HYPOXIA RE-SPONSIVE UNIVERSAL STRESS PROTEIN1, has been shown to coordinate oxygen sensing by PCO/RAP2.12 with H 2 O 2 production by NADPH oxidases, indicating that there is a network connecting diverse signaling pathways downstream of ERF-VII targets (Gonzali et al, 2015).…”