Abstract
The aim of this study is to investigate the metabolic regulation of DMSP (dimethylsulfoniopropionate) biosynthesis in Enteromorpha compressa for the environmental adaptation. DMSP is one of the compatible solutes accumulated in many species of marine algae and a few of higher plants.
We fed the radioactive labeled precursor of DMSP (i.e. methionine) to E.compressa in high salinity medium and analyzed the change in DMSP biosynthesis activity from each precursor. The obtained results suggest the biosynthesis of DMSP in salt-treated E.compressa is regulated by the supply of methionine.
If the biosynthesis of methionine is accelerated on response to salt stress, the expression of the salt-responsive genes involved in methionine biosynthesis may be induced. Cystathionine-γ-synthase (CGS) is known as a key enzyme of methionine biosynthesis in plant. So we isolated CGS gene(s) from E.compressa by RACE method and examined the correlation between the CGS expression and salt stress by RT-PCR.
