Galactoglucomannan oligosaccharides inhibition of elongation growth is in pea epicotyls coupled with peroxidase activity

Growth and anatomical parameters of adventitious roots formed on mung bean hypocotyls are correlated with galactoglucomannan oligosaccharides structure

The effect of galactoglucomannan oligosaccharides (GGMOs) compared with chemically modified oligosaccharides, GGMOs-g (with reduced number of D-galactose side chains) and GGMOs-r (with reduced reducing ends) on mung bean (Vigna radiata (L.) Wilczek) adventitious roots formation, elongation, and anatomical structure have been studied. All types of oligosaccharides influenced adventitious root formation in the same way: stimulation in the absence of exogenous auxin and inhibition in the presence of exogenous auxin. Both reactions are probably related with the presence/content of endogenous auxin in plant cuttings. However, the adventitious root length was inhibited by GGMOs both in the absence as well as in the presence of auxin (IBA or NAA), while GGMOs-g inhibition was significantly weaker compared with GGMOs. GGMOs-r were without significant difference on both processes, compared with GGMOs. GGMOs affected not only the adventitious root length but also their anatomy in dependence on the combination with certain type of auxin. The oligosaccharides influenced cortical cells division, which was reflected in the cortex area and in the root diameter. All processes followed were dependent on oligosaccharides chemical structure. The results suggest also that GGM-derived oligosaccharides may play an important role in adventitious roots elongation but not in their formation.

Oligosaccharides induce changes in protein patterns of regenerating spruce protoplasts

Galactoglucomannan oligosaccharides (GGMOs, d.p. 4–8 and fractions d.p. 3, 4, 5, 6–7), used in culture media for spruce protoplasts derived from callus cells showed a pleiotropic effect. They influenced both, quality and quantity of extracellular proteins in regenerating protoplasts. GGMOs d.p. 4, 5 at pH 6.0 and the mixture of d.p. 4–8 (pH 3.8 and 6.0) after 48 h of culture increased the amount of extra- and intracellular proteins and the viability of protoplasts. The most significant effect on protoplasts viability in the presence of GGMOs d.p. 4–8 without the growth hormone supplementation at pH 3.8, and with lower efficiency in the presence of NAA (1 mg/l) has been observed. The most significant differences were observed in the molecular mass intervals Mr∼17–21 kDa, 25–30 kDa, and 45–60 kDa. After 24 h of culture extracellular acid proteins with Mr∼30; 41; 68; and 90 in media supplemented with GGMOs d.p. 3, 4, 5, 6–7 (pH 6.0) with or without NAA were identified to belong to the group of β-1,3-glucanases. Extracellular proteins p27.5; 30; 41; 50; 52 and 90 exhibited chitinase activity after 24 h of protoplast cultivation. GGMOs probably fulfil a protective role in this process of spruce protoplast regeneration.