Sensitivity of Antarctic freshwater algae to salt stress assessed by fast chlorophyll fluorescence transient.
2013
In this study, we investigated the effects of salt stress (2 mM
NaCl) on excitation energy transfer from light harvesting
complexes to photosystem II (PS II) in two Antarctic algal
species: Klebsormidium sp. and Zygnema sp. Short-term salt
stress led to a significant changes in the shape of chlorophyll
fluorescence transient (OJIP). Analyses of the polyphasic
fluorescence transients (OJIP) showed that the fluorescence
yield at the phases J, I and P declined considerably with the
time of exposition to salt stress. In both experimental
species, OJIP transients reached lowest values of chlorophyll
fluorescence signal after 30/60 min. of NaCl exposition. Then,
OJIP shape and chlorophyll fluo- rescence showed
species-specific recovery and rised towards original values
(about 2/3 of untreated control). Analyses of chlorophyll
fluorescence parameters derived from OJIPs showed that salt
stress led to a decrease in the maximal efficiency of PS II
photo- chemistry (FV/FM) in Zygnema sp. but not Klebsormidium
sp. The results indicated that the probability of excitation
energy transfer before and beyond QA, and the yield of electron
transport beyond QA is limited by salt-induced stress in
Zygnema sp. In addition, salt stress resulted in a decrease in
the photosynthetic electron transport per PS II reaction
center, but both increase and decrease in the trapping per PS
II reaction center was found. Performace index (PIabs) was
affected negatively in Zygnema sp. but possitively
Klebsormidium sp. indicating that the latter species was more
resistant to salt stress than Zygnema sp.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
47
References
13
Citations
NaN
KQI