Abstract:
Regulated cell death (RCD) is central to the development, integrity, and functionality
of multicellular organisms. In the last decade, evidence has accumulated that RCD is a universal
phenomenon in all life domains. Cyanobacteria are of specific interest due to their importance in
aquatic and terrestrial habitats and their role as primary producers in global nutrient cycling. Current
knowledge on cyanobacterial RCD is based mainly on biochemical and morphological observations,
often by methods directly transferred from vertebrate research and with limited understanding of
the molecular genetic basis. However, the metabolism of different cyanobacteria groups relies on
photosynthesis and nitrogen fixation, whereas mitochondria are the central executioner of cell death
in vertebrates. Moreover, cyanobacteria chosen as biological models in RCD studies are mainly
colonial or filamentous multicellular organisms. On the other hand, unicellular cyanobacteria have
regulated programs of cellular survival (RCS) such as chlorosis and post-chlorosis resuscitation.
The co-existence of different genetically regulated programs in cyanobacterial populations may
have been a top engine in life diversification. Development of cyanobacteria-specific methods for
identification and characterization of RCD and wider use of single-cell analysis combined with
intelligent image-based cell sorting and metagenomics would shed more light on the underlying
molecular mechanisms and help us to address the complex colonial interactions during these events.
In this review, we focus on the functional implications of RCD in cyanobacterial communities.