Ricerc@Sapienza

Diatoms (Bacillariophyta), one of the most abundant and diverse groups of marine phytoplankton, respond rapidly to the supply of new nutrients, often out-competing other phytoplankton. Herein, we integrated analyses of the evolution, distribution, and expression modulation of two gene families involved in diatom nitrogen uptake (DiAMT1 and DiNRT2), in order to infer the main drivers of divergence in a key functional trait of phytoplankton. Our results suggest that major steps in the evolution of the two gene families reflected key events triggering diatom radiation and diversification.

Mediterranean mid-altitude sites are critical for the survival of plant species allowing for elevationalvegetation shifts in response to high-amplitude climate variability. Pollen records from the southernBalkans have underlined the importance of the region in preserving plant diversity over at least the lasthalf a million years. So far, there are no records of vegetation and climate dynamics from Balkan refugiawith an Early Pleistocene age.