Changes of plasma membrane ATPase activity, membrane potential and
transmembrane proton gradient in Kandelia candel and Avicennia marina seedlings
with various salinities
Affiliations: Research Center for Eco-Environmental Sciences,
Chinese Academy of Sciences, Beijing 100085, China | School of Life Sciences, Xiamen University, Xiamen
361005, China
Abstract: The salt-secreting mangrove, Avicennia marina, and
non-salt-secreting mangrove, Kandelia candel were cultivated in sand with
various salinities (0‰, 10‰, 20‰, 30‰, 40‰)
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‰; leaves of K.candel: 0–20‰), the
activity of ATPase increased with increasing salinity, while high
salinity (above 30‰ or 20‰) 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‰ (K. candel) or
0–20‰ (A. marina) followed by sharp declining. It indicated that the
structure and function of plasma membrane was damaged severely.
Keywords: salinity, A. marina, K. candel, plasma membrane, H-ATPase, Ca-ATPase, membrane potential, transmembrane proton gradient
