title: Effects of Mg(2+)on spectral characteristics and photosynthetic functions of spinach photosystem II.
abstract: In the present paper we report the results obtained with the photosystem II (PSII) isolated from spinach treated by MgCl(2), and studied the effect of Mg(2+) on spectral characteristics and photosynthetic functions of PSII. The results showed that Mg(2+) treatment at a suitable concentration could significantly increase the absorption intensity of PSII and the intensity ratio of Soret band to Q band of chlorophyll-a. The treatment also elevated the excited peak intensity at 230, 278 and 343 nm, and the emitted peak intensity at 304 and 682 nm, and the ratio of F(278)/F(230), respectively. The results implied that Mg(2+) increased absorbance for visible light, improving energy transfer among amino acids within PSII protein complex and accelerating energy transport from tyrosine residue to chlorophyll-a. The photochemical activity and oxygen evolving rate of PSII were also enhanced by Mg(2+). This is viewed as evidence that Mg(2+) can promote energy transfer and oxygen evolution in PSII of spinach.
authors.affiliation: Medical College of Suzhou University, Suzhou 215123, People's Republic of China.
authors.forename: Chen
authors.initials: C
authors.lastname: Liang
authors.forename: Wu
authors.initials: W
authors.lastname: Xiao
authors.forename: Huang
authors.initials: H
authors.lastname: Hao
authors.forename: Liu
authors.initials: L
authors.lastname: Xiaoqing
authors.forename: Liu
authors.initials: L
authors.lastname: Chao
authors.forename: Zheng
authors.initials: Z
authors.lastname: Lei
authors.forename: Hong
authors.initials: H
authors.lastname: Fashui
mesh_terms: D002734:Chlorophyll / Q000737:chemistry; D000077194:Chlorophyll A; D004579:Electron Transport; D015636:Magnesium Chloride / Q000737:chemistry*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods; D018724:Spinacia oleracea / Q000737:chemistry / Q000378:metabolism
chemical_list: D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D015636:Magnesium Chloride; D002734:Chlorophyll; D000077194:Chlorophyll A