ISSN:
1573-9058
Keywords:
chlorophyll fluorescence induction
;
MgCl2
;
NaCl
;
Na2HPO4
;
Na2PO4
;
Na2SO4
;
spinach
;
Spinacia oleracea
;
state change
;
thylakoids
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Cations such as Mg2+ regulate spillover of absorbed excitation energy mainly in favour of photosystem (PS) 2. Effect of low concentration (〈10 mM) of the monovalent cation Na+ on chlorophyll (Chl) a fluorescence was completely overridden by divalent cation Mg2+ (5 mM). Based on Chl a fluorescence yield and 77 K emission measurements, we revealed the role and effectiveness of anions (Cl-, SO4 2-, PO4 3-) in lowering the Mg2+-induced PS2 fluorescence. The higher the valency of the anion, the lesser was the expression of Mg2+ effect. Anions may thus overcome Mg2+ effects up to certain extent in a valency dependent manner, thereby diverting more energy to PS1 even in the presence of MgCl2. They may do so by reversing Mg2+-induced changes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007159105734
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