Impairment of photosynthetic electron transport in the microalga Chlorella vulgaris by benzenediols: a comprehensive chlorophyll fluorescence analysis
摘要
The effect of benzenediols (pyrocatechol, resorcinol, and hydroquinone) on photosynthetic processes in the microalga Chlorella vulgaris was studied by simultaneously recording of prompt and delayed chlorophyll a fluorescence, as well as the modulated 820 nm reflectance. It was found that benzenediols have an inhibitory effect on photosynthetic electron transport. Benzenediols were found to suppress electron transport on the acceptor side of PSII at the QA and the quinone pool, thereby reducing the energization of thylakoid membranes. At the same time, PSI demonstrated lower sensitivity to benzenediols than PSII. The toxicity of benzenediols was found to depend on their isomeric configuration, concentration, and exposure duration. Pyrocatechol was shown to have the strongest effect on photosynthetic reactions and antioxidant activity compared to hydroquinone and resorcinol. The pivotal parameters of the chlorophyll fluorescence kinetics that are highly sensitive to the benzenediols impact have been identified. According to the JIP test, the parameters M0, VJ and φEo as well as the delayed fluorescence parameters I1/D2 and I4/D2 demonstrated the greatest sensitivity to benzenediols. The obtained results contribute to the development of a methodology for bioassay and bioindication of phenolic pollutants in aquatic environments.