title: Changes of plasma membrane AtPase activity, membrane potential and transmembrane proton gradient in Kandelia candel and Avicennia marina seedlings with various salinities.
abstract: The salt-secreting mangrove, Avicennia marina, and non-salt-secreting mangrove, Kandelia candel were cultivated in sand with various salinities(0 per thousand, 10 per thousand, 20 per thousand, 30 per thousand, 40 per thousand) for 60 d. Plasma membrane vesicles of high-purity in leaves and roots of A. marina and K. candel seedlings were obtained by two-phase partitioning. The function of the plasma membranes, the activity of ATPase, membrane potential and transmembrane proton gradient, at various salinities were investigated. The results showed that within a certain range of salinity (A. marina and roots of K. candel: 0-30 per thousand; leaves of K. candel: 0-20 per thousand), the activity of ATPase increased with increasing salinity, while high salinity (above 30 per thousand or 20 per thousand) inhibited ATPase activity. In comparison with A. marina, K. candel appeared to be more sensitive to salinity. The dynamics of membrane potential and transmembrane proton gradient in leaves and roots of A. marina and K. candel seedlings were similar to that of ATPase. When treated directly by NaCl all the indexes were inhibited markedly: there was a little increase within 0-10 per thousand (K. candel) or 0-20 per thousand (A. marina) followed by sharp declining. It indicated that the structure and function of plasma membrane was damaged severely.
authors.affiliation: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. zqzhao77@yahoo.com.cn
authors.forename: Zhong-Qiu
authors.initials: ZQ
authors.lastname: Zhao
authors.forename: Hai-Lei
authors.initials: HL
authors.lastname: Zheng
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D032407:Avicennia / Q000201:enzymology*; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology*; D002681:China; D008564:Membrane Potentials / Q000502:physiology; D018892:Proton-Motive Force / Q000502:physiology*; D043982:Rhizophoraceae / Q000201:enzymology*; D036226:Seedlings / Q000201:enzymology; D012965:Sodium Chloride / Q000032:analysis; D012987:Soil / Q000032:analysis
chemical_list: D012987:Soil; D012965:Sodium Chloride; D000251:Adenosine Triphosphatases