Cyanobacteria and ultraviolet radiation (UVR) stress: Mitigation strategies

The combined effects of UV-B radiation and herbicides on photosynthesis, antioxidant enzymes and DNA damage in two bloom-forming cyanobacteria

“…However, aquatic organisms have developed a number of repair and tolerance mechanisms to counteract the damaging effects of UV radiation (Quesada and Vincent, 1997;Singh et al, 2010). In this study, both Anabaena and M. viridis had high SOD activity and carotenoid content, which may have decreased ROS generation and MDA production (Tables 1 and 3).…”

“…UV radiation can also alter species composition, and the vertical distribution and metabolism of aquatic ecosystems, which causes shifts in phytoplankton community structure and the food web (Häder et al, 1995;Häder, 2000;Zeeshan and Prasad, 2009). However, cyanobacteria have also developed adaptation strategies to counteract the damaging effects of UV irradiance, which include avoidance, scavenging, screening, repair and programmed cell death (Quesada and Vincent, 1997;Sinha et al, 1998;Sinha and Häder, 2008;Singh et al, 2010).…”

Characterization of the chemical diversity of glycosylated mycosporine-like amino acids in the terrestrial cyanobacterium Nostoc commune

“…The 4-deoxygadusol could conjugate with a nitrogen substituent (e.g., amino acids) to generate MAAs [20,26,27]. The gene product of Ava-3856 from Anabaena variabilis can convert 4-deoxygadusol and glycine into mycosporine-glycine [49].…”

“…There are structurally distinct MAAs found in taxonomically diverse organisms [21][22][23][24][25][26][27]. In cyanobacteria, MAAs protect the cells against solar radiation [28,29].…”

Screening and partial purification of photoprotective pigment scytonemin from cyanobacterial crusts dwelling on the historical monuments in and around Varanasi, India

“…8,9 Several defense strategies have been evolved in cyanobacteria to counteract the damaging effects of UV, such as migration, mat formation, synthesis of antioxidants, presence of specific active repair mechanisms and UV-absorbing compounds. 10,11 The UV-absorbing/ screening compounds such as mycosporine-like amino acids (MAAs) 12 and scytonemin have received fair attention for their potential role in UV photoprotection. 13 Scytonemin, a dimer of indolic and phenolic subunits, is a yellow-brown lipid soluble pigment located in the extracellular polysaccharide sheath of about 300 cyanobacterial species.…”