EFFECT OF GALACTOGLUCOMANNAN-DERIVED OLIGOSACCHARIDES ON ELONGATION GROWTH OF PEA AND SPRUCE STEM SEGMENTS STIMULATED BY AUXIN

Galactoglucomannan-derived oligosaccharides (GGMOs) (degree of polymer ization 4-8) isolated from the wood of poplar (Populus monilifera Ait. ) were shown to be inhibitors of the 2,4-dichlorophenoxyacetic acid-st imulated elongation growth of pea (Pisum sativum L. cv. Tyrkys) and sp ruce [Picea abies (L.) Karst] stem segments. A dependence on the conce ntration of GGMOs (between 10(-5)-10(-10) M) as well as plant species was ascertained. Pea stem segments were much more sensitive (10(-10) M ) than spruce (10(-8) M). The GGMOs did not exhibit toxicity even at h igh concentrations and during long-term bioassays. The timing of the a ction of GGMOs and auxin in the growth process was also studied.