Host-Pathogen interactions. 25. Endopolygalacturonic acid lyase from Erwinia carotovora elicits phytoalexin accumulation by releasing plant cell wall fragments

Journal Article · Sun Jan 01 04:00:00 EST 1984 · Plant Physiol.; (United States)

OSTI ID:6606350

Davis, K R; Lyon, G D; Darvill, A G; Albersheim, P

Heat-labile elicitors of phytoalexin accumulation in soybeans (Glycine max L. Merr. cv Wayne) were detected in culture filtrates of Erwinia carotovora grown on a defined medium containing citrus pectin as the sole carbon source. The heat-labile elicitors were highly purified by cation-exchange chromatography on a CM-Sephadex (C-50) column, followed by agarose-affinity chromatography on a Bio-Gel A-0.5m gel filtration column. The heat-labile elicitor activity co-purified with two ..cap alpha..-1,4-endopolygalacturonic acid lyases (EC 4 x 2 x 2 x 2). Endopolygalacturonic acid lyase activity appeared to be necessary for elicitor activity because heat-inactivated enzyme preparations did not elicit phytoalexins. The purified endopolygalacturonic acid lyases elicited pterocarpan phytoalexins at microbial-inhibitory concentrations in the soybean-cotyledon bioassay when applied at a concentration of 55 nanograms per milliliter (1 x 10/sup -9/ molar). One of these lyases released heat-stable elicitors from soybean cell walls, citrus pectin, and sodium polypectate. The heat-stable elicitor-active material solubilized from soybean cell walls by the lyase was composed of at least 90% (w/v) uronosyl residues. These results demonstrate that endopolygalacturonic acid lyase elicits phytoalexin accumulation by releasing fragments from pectic polysaccharides in plant cell walls.

• Research Organization: Univ. of Colorado, Boulder
• DOE Contract Number: AC02-76ER01426
• OSTI ID: 6606350
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 74:1; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL WALL
DISEASE RESISTANCE
ENZYME ACTIVITY
ENZYMES
FOOD
HOST
INHIBITION
KINETICS
LYASES
METABOLIC ACTIVATION
MICROORGANISMS
PATHOGENS
PLANTS
REACTION KINETICS
SOYBEANS
VEGETABLES