Species-Specificity of an Elicitor-Active Oligosaccharide, LN-3, to Leguminous Plants

Akihiro Tai3 *, Kazuyoshi Kawazub and Akio Kobayashi3 a D epartm ent of Biotechnology, Faculty of Engineering, O saka University, O saka 565, Japan b D epartm ent of Agricultural Science, O kayam a University, O kayam a 700, Japan Z. Naturforsch. 51c, 371-378 (1996): received January 12/February 13, 1996 Elicitor, Species-Specificity, Phytoalexin A ccum ulation, Bean, Pea LN-3, a linear pyridylam inated hepta-ß-glucoside previously found to show elicitor activity in alfalfa cotyledons, was exam ined for phytoalexin-inducing activity in pea epicotyl and bean cotyledon assays. LN-3 did not show (+)-pisatin-inducing activity in pea epicotyls. In the bean cotyledon assay, however, the (± )-k iev itone content gradually increased with increasing LN3 concentration, and reached a maximum (ca. 17 |ig/g fresh wt) at 100 j.ig/ml. Half-maximal elicitor activity was seen at ca. 16 j.i m . A fter three legumes, alfalfa, pea and bean, were treated with LN-3, the recovery of the rem aining LN-3 or its fragm ents was exam ined. Almost 100% of LN-3 or its fragments was recovered from the pea test solution; in contrast, recoveries from alfalfa and bean were only 63.8 and 38.1%, respectively. H PLC and LC-MS analyses of the recovered samples indicated that LN-3 was hydrolyzed to give m onoand/or diglucoside(s) in the alfalfa and the bean solutions, while LN-3 was hydrolyzed to give sugar fragm ents with