Xyloglucan oligosaccharides promote growth and activate cellulase: Evidence for a role of cellulase in cell expansion. [Pisum sativum L]

Journal Article · Sun Jul 01 00:00:00 EDT 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.93.3.1042· OSTI ID:5647029

McDougall, G J; Fry, S C ^[1]

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1. Univ. of Edinburgh (England)

Oligosaccharides produced by the action of fungal cellulase on xyloglucans promoted the elongation of etiolated pea (Pisum sativum L.) stem segments in a straight-growth bioassay designed for the determination of auxins. The oligosaccharides were most active at about 1 micromolar. We tested the relative growth-promoting activities of four HPLC-purified oligosaccharides which shared a common glucose{sub 4} {center dot} xylose{sub 3} (XG7) core. The substituted oligosaccharides XG8 (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose) and XG9n (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose{sub 2}) were more effective than XG7 itself and XG9 (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose {center dot} fucose). The same oligosaccharides also promoted the degradation, assayed viscometrically, of xyloglucan by an acidic cellulase from bean (Phaseolus vulgaris L.) leaves. The oligosaccharides were highly active at 10{sup {minus}4} molar, causing up to a fourfold increase in activity, but the effect was still detectable at 1 micromolar. Those oligosaccharides (XG8 and XG9n) which best promoted growth, stimulated cellulase activity to the greatest extent. The oligosaccharides did not stimulate the action of the cellulase in an assay based on the conversion of ({sup 3}H)xyloglucan to ethanol-soluble fragments. This suggests that the oligosaccharides enhanced the midchain hydrolysis of xyloglucan molecules (which would rapidly reduce the viscosity of the solution), at the expense of cleavage near the termini (which would yield ethanol-soluble products).

• OSTI ID: 5647029
• Journal Information: Plant Physiology; (USA), Vol. 93:3; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CELLULASE
BIOLOGICAL FUNCTIONS
OLIGOSACCHARIDES
BIOCHEMICAL REACTION KINETICS
PISUM
PHYSIOLOGY
FUNGI
PLANT CELLS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
CARBOHYDRATES
ENZYMES
GLYCOSYL HYDROLASES
HYDROGEN COMPOUNDS
HYDROLASES
ISOTOPE APPLICATIONS
KINETICS
LEGUMINOSAE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
PLANTS
REACTION KINETICS
SACCHARIDES
550201* - Biochemistry- Tracer Techniques