Allelopathic mechanism of pyrogallol to Microcystis aeruginosa PCC7806 (Cyanobacteria): From views of gene expression and antioxidant system

Microcystin-degrading bacteria affect mcyD expression and microcystin synthesis in Microcystis spp.

“…Iron deficient conditions resulted in an increase of mcyD and mcyH transcription, correlating with an increase in microcystin-leucine-arginine (MC-LR) levels (Sevilla et al, 2008;Alexova et al, 2011). Pyrogallol stress, a potent allelochemical, up-regulated mcyB gene expression in Microcystis (Shao et al, 2009). On consumption by Daphnia, mcyA gene expression was up-regulated in Microcystis and production of MCs increased (Pineda-Mendoza et al, 2014).…”

Effects of pyrogallic acid on Microcystis aeruginosa: oxidative stress related toxicity

“…Malondialdehyde (MDA) was a product of lipid peroxidation product. Shao et al (2009) reported that levels of MDA in M.aeruginosa exposed to 4 mg L À 1 PA were significantly higher than those of the controls. From these results, it can be found that the loss of membrane integrity in M.aeruginosa exposed PA was probable because of membrane lipid peroxidation due to overproduction of ROS induced by PA.…”

“…Among these polyphenolic compounds, PA showed the strongest inhibitory activity to Microcystis aeruginosa with 50% effect concentration (EC 50 ) of 0.65-2.97 mg L À 1 (Nakai et al, 2000;Zhu et al, 2010). Previous studies proposed that the inhibitory effect of PA against M. aeruginosa may involve of oxidative stress (Wu et al, 2007), interruption of the electron transfer chain of PSII (Dziga et al, 2007;Zhu et al, 2010), and interfering the expression of antioxidative gene (Shao et al, 2009). However, the complete molecular mechanism underlying its toxicity on phytoplankton…”

Effects of Allelochemicals from Ficus microcarpaon Chlorella pyrenoidosa

“…In addition, O 2 − • derived from the initial electron donation is a precursor of reactive oxygen species, and limits the reactivity of molecular oxygen (O 2 ). Once the unfavorable O 2 − • has been produced, the oxidation of reactive oxygen species will propagate in a variety of other biological molecules, including H 2 O 2 , hydroxyl radical and singlet oxygen, which induce oxidative damage in lipids, proteins and DNA (Shao et al 2009). SOD can specially catalyze the conversion of O 2 − • into H 2 O 2 and O 2 , acting as the first line of defense against the potential toxicity of superoxide radical.…”