TITLE	Influence of Fe- and Mg-deficiency on the thylakoid membranes of a chlorophyll-deficient ch5 mutant of Arabidopsis thaliana
AUTHOR	Yih-Kuang Lu Department of Botany, National Taiwan University, Taipei, Taiwan 106, Republic of China Yung-Reui Chen Department of Botany, National Taiwan University, Taipei, Taiwan 106, Republic of China Chi-Ming Yang Institute of Botany, Academia Sinica, Nankang, Taipei, Taiwan 115, Republic of China
FULL TEXT	[in HTML format] [in PDF format]
ABSTRACT	We characterized the thylakoid membranes of a chlorophyll-deficient ch5 mutant and a wild type of Arabidopsis thaliana grown in Murashige and Skoog medium with and without Fe or Mg by their composition and surface tension, and by the influence of surfactant on the thylakoid membranes. Deficiency in Fe and Mg decreases the amount of chlorophyll and protein in the ch5 mutant and wild type, but dramatically increases the amount of carotenoid. The pattern of the first-derivative absorption spectra of chloroplast revealed that the composition and organization of thylakoid membranes were very different in the two biotypes. In both biotypes, the surface tension of Fe- or Mg-deficient thylakoid membranes was greater than that in plants grown in normal media, indicating that the thylakoid membranes of Fe- or Mg-deficient plants are more easily accessed by surfactants than those of normally-grown plants. In both biotypes, chlorophyll was more easily solubilized from the thylakoid membranes of Mg-deficient plants than that of Fe-deficient plants, which was more easily solubilized than normally grown plants. We concluded that Fe- or Mg-deficiency results in a looser organization of thylakoid membranes than in the controls, and that Mg-deficiency results in a more disorganized thylakoid membrane than does Fe-deficiency. Results suggest that Fe- and Mg-deficient thylakoids contain smaller amounts of the light-harvesting complexes associated with photosystem II (LHCII) and an abnormal ratio of monogalactosyl diglyceride to digalactosyl diglyceride (MGDG/DGDG).
KEYWORD	Chlorophyll-deficiency; Fe-deficiency; Light-harvesting complex II; Mg-deficiency; Surface tension; Surfactant; Thylakoid membranes;
ARTICLE INFO	Botanical Bulletin of Academia Sinica, Volume 36 Number 3 July 1995, page 175-179, 5 pages
PUBLISHER	Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, Republic of China