Circadian and diurnal gene expression in three axenic Trebouxia algal species

Trebouxia species are the most common and diverse photosynthetic partners in lichen symbioses, yet their chronobiology — which likely contributes to modulating the symbiosis and environmental adaptation — remains largely unexplored. Here, we identify rhythmic gene expression in cultures of three closely related Trebouxia species (S09, S12, S19) with distinct climatic niche preferences. To explore rhythmic patterns in these three species, axenic cultures were exposed to either diurnal light/dark cycles or constant light for 72 hours.