Real-time monitoring of superoxide anion radical generation in response to wounding: electrochemical study

Abstract

BackgroundThe growth and development of plants is deleteriously affected by various biotic and abiotic stress factors. Wounding in plants is caused by exposure to environmental stress, mechanical stress, and via herbivory. Typically, oxidative burst in response to wounding is associated with the formation of reactive oxygen species, such as the superoxide anion radical (O2•−), hydrogen peroxide (H2O2) and singlet oxygen; however, few experimental studies have provided direct evidence of their detection in plants. Detection of O2•− formation in plant tissues have been performed using various techniques including electron paramagnetic resonance spin-trap spectroscopy, epinephrine-adrenochrome acceptor methods, staining with dyes such as tetrazolium dye and nitro blue tetrazolium (NBT); however, kinetic measurements have not been performed. In the current study, we provide evidence of O2•− generation and its kinetics in the leaves of spinach (Spinacia oleracea) subjected to wounding.MethodsReal-time monitoring of O2•− generation was performed using catalytic amperometry. Changes in oxidation current for O2•− was monitored using polymeric iron-porphyrin-based modified carbon electrodes (φ = 1 mm) as working electrode with Ag/AgCl as the reference electrode.ResultThe results obtained show continuous generation of O2•− for minutes after wounding, followed by a decline. The exogenous addition of superoxide dismutase, which is known to dismutate O2•− to H2O2, significantly suppressed the oxidation current.ConclusionCatalytic amperometric measurements were performed using polymeric iron-porphyrin based modified carbon electrode. We claim it to be a useful tool and a direct method for real-time monitoring and precise detection of O2•− in biological samples, with the potential for wide application in plant research for specific and sensitive detection of O2•−.

On the stress-induced photon emission from organism: II, how will the stress-transfer kinetics affect the photo-genesis?

“…Equations (28), (33), (37), and (41) are implemented for assessing the responses of the stress-transfer processes hypothesized to contain a single second-order low-pass pathway with fixed kinetic rates but differing in the damping, to a step stress. Equations (45), (49), (53), and (57) are implemented to assess the responses of the stress-transfer processes hypothesized to contain a single second-order band-pass pathway with fixed kinetic rates but differing in damping, to a step stress. The equations to be numericized are implemented according to the following principles: (1) The kinetics is evaluated over a timescale of [0 1] with a temporal resolution of 10 −4 .…”

Reactive Oxygen Species as a Response to Wounding: In Vivo Imaging in Arabidopsis thaliana

“…In photosynthetic organism, generation of reactive oxygen species (ROS) is a quite universal and fast defense mechanism, known to be associated with various stresses both in vivo and in vitro (Yadav and Pospíšil, 2012;Prasad et al, 2015;Prasad et al, 2016;Prasad et al, 2017a;Prasad et al, 2018;Kumar et al, 2019), in both local as well as systemic responses (Grant and Loake, 2000;Slesak et al, 2007). In tomato, it has been observed that hydrogen peroxide (H 2 O 2 ) was produced at the site within an hour of wounding and its level was enhanced even in distant part (upper unwounded leaves) in the following 4 to 6 h (Orozco-Cardenas and Ryan, 1999).…”

Dietary limonCitrus × latifoliafruit peel essential oil improves antioxidant capacity of tambaqui (Colossoma macropomum) juveniles

“…In disagreement with our observations, Ruiz‐Pérez et al., (2016) found that EOCL (0.008, 0.08 and 0.8 µg/ml) did not change the ROS content in a genotoxic test using the Salmonella typhimurium TA102 model. Finally, the use of 0.5 and 1 ml EOCL/kg diet was able to enhance hepatic SOD activity, indicating a better capacity to scavenge the anion superoxide, which is a potent inflammatory and oxidant molecule (Prasad et al, 2017). This might suggest that this oil can be an alternative to improve the primary antioxidant defence mechanism system of fish.…”