摘要：Salinity promotes the generation of reactive oxygen species (ROS) and oxidative
damages of different cellular components. Thus, salt stress tolerance requires
activation of antioxidative pathways to protect plant cells from damages. In this
study, seedlings of Salsola aucheri were treated with 100, 200, 300, 400 and 500
mM of NaCl and consequently, the activities of some antioxidant enzymes were
evaluated. Enhanced activities of catalase (CAT), peroxidase (POD) and superoxide
dismutase (SOD) were determined by the increasing salinity up to 300 mM.
Furthermore, accumulation of glycinebetaine (GB) as a common response to salt
stress was assessed. Accordingly, the concentration of GB enhanced by the
increasing concentration of NaCl up to 300 mM and decreased at NaCl
concentrations of 400 and 500 mM. Likewise, assessing the activity of betaine
aldehyde dehydrogenase (BADH) as a key enzyme in the biosynthesis of GB
showed that BADH activity enhanced by the increasing salinity (up to 300 mM
NaCl) and decreased at the higher concentrations of NaCl. Cloning and
characterization of BADH cDNA from Salsola aucheri and the expression pattern of
BADH transcript were also examined. An open reading frame of 797 bp encoded a
protein which showed high homology to BADH enzymes in other plants. These
results suggest that the salinity tolerance of Salsola aucheri might be closely
associated with the increasing function of the antioxidative system to scavenge
reactive oxygen species and with the accumulation of the osmoprotectant
glycinebetaine.
