Accumulation of phenolic compounds in Spirogyra in stress conditions

Phenolic substances represent one of the major groups of secondary metabolites of higher plants that play a role in a number of biotic and abiotic interactions. Among algal groups, these substances are produced, for example, by conjugating algae (Zygnematophyceae), which are currently considered to be the closest living relatives of higher plants. The common function of phenolic substances is protection against the harmful effects of ultraviolet radiation, or even an excessive amount of photosynthetically active radiation, which was supported by the induction of their synthesis after exposure to UV radiation in several ecophysiological studies. However, the range of applied stress factors and their effect on changes in phenol levels is limited. In this diploma thesis, the genus Spirogyra, for which the chemical structure of a number of specific phenolic substances is known, was exposed to selected stress factors and their influence on cell morphology, maximum quantum yield Fv/Fm and quantity of phenolic substances was monitored. A significant increase was observed after application of UV-B radiation, higher level of PAR, low temperature and osmotic stress, while at high temperature this effect was not evident. Increased production upon UV-B exposure further underlines the importance of phenolic..