Cell differentiation in cyanobacteria desmonostoc Sp. under different phosphorus concentrations and its potential as a growth promoter for the aquatic macrophyte Salvinia Auriculata

Abstract

Cyanobacteria and aquatic macrophytes are organisms that perform important ecosystem services and influence the dynamics of the ecosystems in which they occur. Both can positively or negatively affect their environments, depending on local conditions. Cyanobacteria carry out oxygenic photosynthesis, and some are capable of fixing atmospheric nitrogen, making it bioavailable to other organisms. Among nitrogen-fixing cyanobacteria, heterocytous strains are able to differentiate specialized cells heterocytes and akinetes. Heterocytes are specialized in nitrogen (N) fixation, while akinetes store reserves and enter dormancy under adverse conditions, providing adaptive advantages by enabling survival in stressful environments. Cell differentiation is genetically regulated and influenced by environmental factors, such as nutrient availability. Nitrogen limitation is a known trigger for differentiation, but phosphorus (P), a macronutrient involved in various metabolic processes may also play a crucial role. Variations in P availability can trigger the differentiation of both heterocytes and akinetes. Cyanobacteria can influence other organisms by forming endophytic or epiphytic associations, providing fixed nitrogen to their hosts and potentially promoting plant growth. Aquatic macrophytes, such as Salvinia auriculata, can harbor a diversity of cyanobacteria that may contribute to their growth. Given this context, we evaluated cell differentiation in the cyanobacterium Desmonostoc sp. UFLA12 under different phosphorus concentrations. We then inoculated this strain into a medium with S. auriculata to assess its potential to promote macrophyte growth. We found that phosphorus availability influenced heterocyte production and akinete differentiation in Desmonostoc sp. UFLA12. Moreover, this strain enhanced the clonal growth of S. auriculata. We conclude that phosphorus availability affects cellular differentiation in Desmonostoc sp. UFLA12, and that its inoculation contributes to the rapid and vigorous spread of S. auriculata, even in oligotrophic environments.