Host-pathogen interactions. XXIX. Oligogalacturonides released from sodium polypectate by endopolygalacturonic acid lyase are elicitors of phytoalexins in soybean. [Glycine max L]

Journal Article · Sat Feb 01 04:00:00 EST 1986 · Plant Physiol.; (United States)

OSTI ID:5620954

Davis, K R; Darvill, A G; Albersheim, P; Dell, A

Recent studies have demonstrated that an apparently homogeneous preparation of an ..cap alpha..-1,4-D-endopolygalacturonic acid lyase (EC 4.2,2.2) isolated from the phytopathogenic bacterium Erwinia carotovora induced phytoalexin accumulation in cotyledons of soybean (Glycine max (L.) Merr. cv Wayne) and that this pectin-degrading enzyme released heat-stable elicitors of phytoalexins from soybean cell walls, citrus pectin, and sodium polypectate. The present paper reports the purification, by anion-exchange chromatography on QAE-Sephadex columns followed by gel-permeation chromatography on a Bio-Gel P-6 column, of the two fractions with highest specific elicitor activity present in a crude elicitor-preparation obtained by lyase treatment of sodium polypectate. Structural analysis of the fraction with highest specific elicitor activity indicated that the major, if not only, component was a decasaccharide of ..cap alpha..-1,4-D-galactosyluronic acid that contained the expected product of lyase cleavage, 4-deoxy-..beta..-L-5-threo-hexopyranos-4-enyluronic acid (4,5-unsaturated galactosyluronic acid), at the nonreducing terminus. This modified decagalacturonide fraction exhibited half-maximum and maximum elicitor activity at 1 microgram/cotyledon (6 micromolar) and 5 micrograms/cotyledon (32 micromolar) galactosyluronic acid equivalents, respectively. Reducing 90 to 95% of the carboxyl groups of the galactosyluronic acid residues abolished the elicitor activity of the decagalacturonide fraction. The second most elicitor-active fraction contained mostly undeca-..cap alpha..-1,4-D-galactosyluronic acid that contained 4,5-unsaturated galactosyluronic acid at the nonreducing termini. This fraction exhibited half-maximum and maximum elicitor activity at approximately 3 micrograms/cotyledon (17 micromolar) and 6 micrograms/cotyledon (34 micromolar) galactosyluronic acid equivalents, respectively.

• Research Organization: Univ. of Colorado, Boulder
• DOE Contract Number: AC02-76ER01426
• OSTI ID: 5620954
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 80:2; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
BACTERIA
BIOLOGICAL ACCUMULATION
BLOOD SUBSTITUTES
CARBOHYDRATES
CARBOXYLIC ACIDS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHROMATOGRAPHY
COLLOIDS
DATA
DECOMPOSITION
DISPERSIONS
DRUGS
ENZYME ACTIVITY
ENZYMES
EXPERIMENTAL DATA
GALACTURONIC ACID
GELS
GLYCINE HISPIDA
HEMATOLOGIC AGENTS
HOST
HYDROXY ACIDS
INFORMATION
ION EXCHANGE CHROMATOGRAPHY
LEAVES
LEGUMINOSAE
LYASES
METABOLITES
MICROORGANISMS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
PATHOGENS
PECTINS
PLANTS
POLYSACCHARIDES
PURIFICATION
RHIZOBIUM
SACCHARIDES
SEPARATION PROCESSES