Induction of defense responses by synthetic glycopeptides that have a partial structure of the elicitor in the spore germination fluid of Mycosphaerella pinodes.
A high molecular weight elicitor (> 70 kDa) from spore germination fluid of a pea pathogen, Mycosphaerella pinodes, has a partial structure of beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man, which is O-glycosidically attached to serine in the protein moiety. To elucidate the minimum structure for the elicitor activity to pea plants, the effects of nine glycopeptides including beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man-O-Ser (No. 1) to [beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man]3-O-Ser3-Pro3 (No. 9) on the infection by M. pinodes, superoxide generation and ATPase activity were measured. The glycopeptides [beta-D-Glc-(1-->6)-alpha-D-Man-(1-->6)-D-Man]-O-Ser2-Pro2 (No. 3) to No. 9 induced rejection reaction of pea tissue against M. pinodes. The glycopeptides No. 3 to No. 9 also induced superoxide generation on uninjured pea leaves. Moreover, the glycopeptides No. 3 to No. 9 induced in vitro the activation of cell wall-bound ATPase and superoxide generation system in the protein fraction solubilized from pea cell wall. The results indicate that the synthetic glycopeptides, No. 3 to No. 9, are available to analyze the signal transduction cascade leading to defense responses and the receptor for the elicitor.
Kiba
A
A
Laboratory of Plant Pathology and Genetic Engineering, College of Agriculture, Okayama University, Japan.
Takeda
T
T
Kanemitsu
T
T
Toyoda
K
K
Ichinose
Y
Y
Yamada
T
T
Shiraishi
T
T
D000595:Amino Acid Sequence; D002240:Carbohydrate Sequence; D006020:Glycopeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000187:drug effects / Q000382:microbiology* / Q000502:physiology; D010935:Plant Diseases; D013172:Spores, Fungal / Q000502:physiology; D013329:Structure-Activity Relationship; D013481:Superoxides / Q000378:metabolism; D013098:Xylariales / Q000187:drug effects / Q000502:physiology*
D006020:Glycopeptides; D013481:Superoxides