Acetylacetone Interferes with Carbon and Nitrogen Metabolism of Microcystis aeruginosa by Cutting Off the Electron Flow to Ferredoxin

Abstract

The regulation of photosynthetic machinery with a nonoxidative approach is a powerful but challenging strategy for the selective inhibition of bloom-forming cyanobacteria. Acetylacetone (AA) was recently found to be a target-selective cyanocide for Microcystis aeruginosa, but the cause and effect in the studied system are still unclear. By recording of the chemical fingerprints of the cells at two treatment intervals (12 and 72 h with 0.1 mM AA) with omics assays, the molecular mechanism of AA in inactivating Microcystis aeruginosa was elucidated. The results clearly reveal the effect of AA on ferredoxin and the consequent effects on the physiological and biochemical processes of Microcystis aeruginosa. In addition to its role as an electron acceptor of photosystem I, ferredoxin plays pivotal roles in the assimilation of nitrogen in cyanobacterial cells. The effect of AA on ferredoxin and on nonheme iron of photosystem II first cut off the photosynthetic electron transfer flow and then interrupted the synthesis of adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH), which ultimately might affect carbon fixation and nitrogen assimilation metabolisms. The results here provide missing pieces in the current knowledge on the selective inhibition of cyanobacteria, which should shed light on the better control of harmful blooms.

Design, Synthesis, and Bioassay for the Thiadiazole-Bridged Thioacetamide Compound as Cy-FBP/SBPase Inhibitors Based on Catalytic Mechanism Virtual Screening

“…PCC6803 cells (Figure ). We found that the resulting differential metabolites were all located downstream of the Calvin cycle; namely, the glycolysis/gluconeogenesis pathway, pentose phosphate pathway, the tricarboxylic acid (TCA) cycle (including the branched glyoxylate cycle), and the amino acid metabolism were involved. − …”

Benzotriazole Ultraviolet Stabilizers (BUVSs) as Potential Protein Kinase Antagonists in Rice

“…As critical biochemical reactions and defense responses in leaves were recognized to be activated prior to visible phenotypic end points, − the inhibited plant growth is proposed to be an indication of the disturbance of photosynthesis, respiration, and transpiration processes. , Four parameters associated with photosynthesis, respiration, and transpiration of rice leaves were evaluated, including the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), and water use efficiency (WUE). Little change in these indicators was observed in the treatment group of 1 μg/L BUVSs.…”

Selenite-Catalyzed Reaction between Benzoquinone and Acetylacetone Deciphered the Enhanced Inhibition on Microcystis aeruginosa Growth

“…In previous work, we found that the simplest β -diketone, acetylacetone (AA), which is naturally present in fruits and vegetables as well as in treated sludge liquors, could enhance the redox conversion of quinones, either by acting as an electron donor for benzoquinone (BQ) or serving as an electron acceptor for hydroquinone (BQH 2 ) . Inspired by this observation, we have further demonstrated that AA could efficiently inhibit the growth of Microcystis aeruginosa (M. aeruginosa), which is one of the notorious bloom-forming and toxic cyanobacteria. , Unlike some other extensively used cyanocides, such as hydrogen peroxide, permanganate, and copper salts, AA works on M. aeruginosa in a nonoxidative way .…”

“…11 Inspired by this observation, we have further demonstrated that AA could efficiently inhibit the growth of Microcystis aeruginosa (M. aeruginosa), which is one of the notorious bloom-forming and toxic cyanobacteria. 12,13 Unlike some other extensively used cyanocides, such as hydrogen peroxide, permanganate, and copper salts, AA works on M. aeruginosa in a nonoxidative way. 12 The interference in electron transfer between two quinones (Q A and Q B ) in photosystem II was regarded as one of the function mechanisms of AA on M. aeruginosa.…”