Chlorophyll fluorescence induction curves were used as a means to assess the functional condition of the photosynthetic apparatus in cells of the halotolerant green microalga Dunaliella maritima (Massjuk) (division Chlorophyta) exposed to hyperosmotic salt shock of various intensities. The shock was caused by the transfer of algal cells grown in the medium with 0.5 M NaCl to the media with elevated NaCl concentrations (1.0, 1.5, and 2.0 M). Parameters of chlorophyll fluorescence (F 0, F m, F 0′, F t′) were measured by means of a specialized pulse-amplitude-modulation fluorometer PAM 2100. In addition, the rate of photosynthetic oxygen evolution as well as the intracellular Na+ and glycerol content (the main osmolyte in this microalga) were determined. The hyperosmotic salt shock was found to elevate the intracellular Na+ content and reduce the functional activity of PSII in D. maritima. The suppression of PSII activity was evident from the decrease in the maximal quantum yield of photochemical energy conversion in PSII, the decreased rate of linear electron transport, the increased reduction of the primary acceptor QA, and the suppression of photosynthetic O2 evolution. The functional activity of PSII recovered gradually along with restoration of osmotic and ionic balance in algal cells. It is proposed that PSI ensures energy supply during cell responses of D. maritima to hyperosmotic salt shock.
Russian Journal of Plant Physiology – Springer Journals
Published: Dec 23, 2011
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera