STSM2 Report Nikolaos Nenadis

UV radiation & water limitation effect on leaf phenolic antioxidants

Dr. Nikolaos Nenadis visited Dr. Laura Llorens Guasch in Spain (7 days in March 2012)

Environmental stimuli (e.g. UV irradiation) may affect the levels of secondary metabolites such as phenolic compounds and consequently the antioxidant activity of plant food and extracts. This STSM was made in order to establish collaboration with other researchers working in the field of UV radiation and combine interdisciplinarity. During the visit I obtained background on the set up of experiments in the field, on the indices and techniques used to monitor UV effects on plant growth, and obtained leaf samples which were about to be analyzed at Aristotle University in Greece with regards to phenolic content and antioxidant activity. The sampled leaves were selected from two Mediterranean species, namely Arbutus unedo and Phillyrea angustifolia growing under three different UV treatments and/or receiving different levels of precipitation. So far samples have been collected from two experimental seasons (autumn and winter) and after freeze-drying during my visit were transferred to Greece for scheduled analyses. The experiment and the analyses will continue as the full study will comprise samples from spring and summer. In this way a better view regarding the effects of the aforementioned abiotic factors to the level of phenolic compounds and antioxidant activity of leaf extracts from the two species will be achieved.