Alginic acids in Lessonia vadosa:: Partial hydrolysis and elicitor properties of the polymannuronic acid fraction

Extraction of Lessonia vadosa (Laminariales, Phaeophyta) collected in three different localities near Punta Arenas in the south of Chile, with 3% aqueous sodium carbonate solutions gave a sodium alginate yield in the range 3.0-17.7% dry weight. There were marked differences in the mannuronic acid to guluronic acid ratio (M/G) (0.21-1.69) in the alginic acids, samples collected in Puerto del Hambre in winter were composed mainly of mannuronic acid residues. The alginate samples were characterized by partial hydrolysis and FT-IR spectroscopy. No relationship was found between tissue type and polyguluronic acid content. The elicitor activity of the polymannuronic acid enriched fraction from alginic acid of blades from Puerto del Hambre was assayed in wheat plants. The polymannuronic acid enriched fraction induced substancial elicitation of phenylalanine ammonia-lyase (PAL) and peroxidase (POD) activities.