The Involvement of Nitric Oxide in Integration of Plant Physiological and Ultrastructural Adjustments in Response to Arsenic

Abstract

High arsenic (As) concentrations are toxic to all the living organisms and the cellular response to this metalloid requires the involvement of cell signaling agents, such as nitric oxide (NO). The As toxicity and NO signaling were analyzed in Pistia stratiotes leaves. Plants were exposed to four treatments, for 24 h: control; SNP [sodium nitroprusside (NO donor); 0.1 mg L-1]; As (1.5 mg L-1) and As + SNP (1.5 and 0.1 mg L-1, respectively). The absorption of As increased the concentration of reactive oxygen species and triggered changes in the primary metabolism of the plants. While photosynthesis and photorespiration showed sharp decrease, the respiration process increased, probably due to chemical similarity between arsenate and phosphate, which compromised the energy status of the cell. These harmful effects were reflected in the cellular structure of P. stratiotes, leading to the disruption of the cells and a possible programmed cell death. The damages were attenuated by NO, which was able to integrate central plant physiological processes, with increases in non-photochemical quenching and respiration rates, while the photorespiration level decreased. The increase in respiratory rates was essential to achieve cellular homeostasis by the generation of carbon skeletons and metabolic energy to support processes involved in responses to stress, as well to maintaining the structure of organelles and prevent cell death. Overall, our results provide an integrated view of plant metabolism in response to As, focusing on the central role of NO as a signaling agent able to change the whole plant physiology.

Improving water use efficiency by changing hydraulic and stomatal characteristics in soybean exposed to drought: the involvement of nitric oxide

“…However, in the long term, the increase in photorespiration, together with the decrease in the photosynthetic rate, may result in a negative carbon balance, which was probably one of the main factors responsible for the decrease in productivity and biomass accumulation observed in BR 16. The carbon balance was reestablished by NO, a molecule that may have an inhibitory effect on photorespiration (Farnese et al ).…”

“…However, in the long term, the increase in photorespiration, together with the decrease in the photosynthetic rate, may result in a negative carbon balance, which was probably one of the main factors responsible for the decrease in productivity and biomass accumulation observed in BR 16. The carbon balance was reestablished by NO, a molecule that may have an inhibitory effect on photorespiration (Farnese et al 2017). Stomatal closure, a commonly observed response in plants exposed to drought, can decrease transpiration and prevent tissue desiccation as well as contribute to greater water use efficiency (Martins et al 2016).…”

5‐[2‐(N‐(Substituted phenyl)acetamide)]amino‐1,3,4‐thiadiazole‐2‐sulfonamides as Selective Carbonic Anhydrase II Inhibitors with Neuroprotective Effects

“…The excessive release of NO can cause neurotoxicity and many neurodegenerative diseases by mediating oxidative stress in human body. SNP is widely used as a direct donor of NO in experiments . Rat pheochromo cytoma PC12 cells are commonly used as nerve cells in study of neurodegenerative diseases .…”

Elongation of stigmatic papillae induced by heat stress is associated with disturbance of pollen attachment inArabidopsis thaliana

“…In situ detection of O 2 − , Ca 2+ and NO using nitro blue tetrazolium (NBT), Calcium green solution and Diaminofluorescein-2 (DAF-2), respectively were performed as previouslydescribed (Farnese et al, 2017; Iwano et al, 2014; Xing et al, 2013). Flowers with type1 and type 4 stigma were detached from plants grown under controlled conditions or subjected to heat stress.…”