Exogenous spermidine alleviates UV-induced growth inhibition of Synechocystis sp. PCC 6803 via reduction of hydrogen peroxide and malonaldehyde levels.
Effects of exogenously added spermidine (Spd) to UV-treated Synechocystis sp. PCC 6803 cultures on their growth, intracellular pigments, hydrogen peroxide (H2O2), malonaldehyde (MDA) contents, and antioxidant enzymes were investigated. Growth inhibition of cells subjected to 1-h UV-A, UV-B, and UV-C irradiation was abolished in culture added with 0.5 mM Spd. Both chlorophyll a and carotenoid contents were decreased under UV radiations in cells grown in BG11 medium. However, the contents of these two pigments were slightly increased under UV radiations in Spd-supplemented cells with the consequence of enhanced oxygen evolution. Intracellular levels of H2O2 and MDA generated during 1-h UV irradiation were decreased when the culture medium contained 0.5 mM Spd. The antioxidative enzymes, catalase, and superoxide dismutase had a little or no response towards Spd supplementation under UV irradiation except for some increase in superoxide dismutase activity under UV-C. Total intracellular polyamines were decreased during Spd supplementation under UV stress; however, the cells showed a drastic increase in the amount of Put under this condition. Altogether, exogenous Spd is likely a potential compound that enables Synechocystis cells to cope with UV stress.
Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand, saowarath@gmail.com.
Saowarath
S
Jantaro
Wipawee
W
Baebprasert
Chaichana
C
Piyamawadee
Orawan
O
Sodsuay
Aran
A
Incharoensakdi
D000975:Antioxidants / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000378:metabolism*; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D015227:Lipid Peroxidation / Q000187:drug effects / Q000528:radiation effects; D008315:Malondialdehyde / Q000378:metabolism*; D010788:Photosynthesis / Q000187:drug effects / Q000528:radiation effects; D010860:Pigments, Biological / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism; D013095:Spermidine / Q000494:pharmacology*; D046939:Synechocystis / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000975:Antioxidants; D010860:Pigments, Biological; D011073:Polyamines; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D013095:Spermidine