Impact of galactoglucomannan oligosaccharides on elongation growth in intact mung bean plants

The impact of exogenously applied galactoglucomannan oligosaccharides (GGMOs) and their structurally modified forms (GGMOs-r—galactoglucomannosyl alditols, GGMOs-g—with reduced galactose content) on the growth of mung bean (Vigna radiata (L.) Wilczek) intact plants cultured in hydroponics has been determined. GGMOs alone or in combination with exogenously added IBA have influenced (with stimulation and/or inhibition effect) hypocotyl and seminal root elongation, adventitious and lateral roots formation and elongation in dependency on their concentration used. The inhibition of elongation growth in hypocotyls as well as in roots was connected with changes of cell wall-associated peroxidases activity and is probably associated with the beginning of cell wall rigidification. Data presented in this paper confirm the hypothesis that exogenously added GGMOs may have antiauxin activity and may interact also with endogenous growth regulators. Certain monosaccharide sequences with terminal galactose in the side chain of GGMOs probably play important role in their biological activity in intact plants as it was demonstrated previously in individual parts of plants.