A saponin correlated with variable resistance of Barbarea vulgaris to the diamondback moth Plutella xylostella

• Published in: Journal of chemical ecology Vol. 29; no. 6; pp. 1417 - 1433
• Main Authors: AGERBIRK, Niels, OLSEN, Carl E, BIBBY, Bo M, FRANDSEN, Hanne O, BROWN, Lea D, NIELSEN, Jens K, RENWICK, J. Alan A
• Format: Journal Article
• Language: English
• Published: New York, NY Springer 01.06.2003; Springer Nature B.V
• Subjects: Adaptation, Physiological; Agronomy. Soil science and plant productions; Animals; Barbarea - chemistry; Bioassays; Biological and medical sciences; Biological Assay; Butterflies & moths; Correlation analysis; Feeding Behavior; Foliage; Fractionation; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; Insects; Larva - growth & development; Larvae; Larval development; Moths - growth & development; Oleanolic Acid - analogs & derivatives; Oleanolic Acid - isolation & purification; Oleanolic Acid - pharmacology; Pest animals; Pest Control, Biological; Pest resistance; Plant Leaves - chemistry; Resistance to control; Saponins - isolation & purification; Saponins - pharmacology; Seasons; Varietal selection. Specialized plant breeding, plant breeding aims; Feeding behavior; Insecta; Survival; Saponin; Plutella xylostella; Pest; Larva; Vegetable crop; Cruciferae; Animal plant relation; Arthropoda; Dicotyledones; Insect resistance; Angiospermae; Lepidoptera; Triterpene; Spermatophyta; Hyponomeutidae; Invertebrata
• DOI: 10.1023/A:1024217504445
• ISSN: 0098-0331

Two types of Barbarea vulgaris var. arcuata, the G-type and the P-type, differed in resistance to larvae of the diamondback moth (DBM) Platella xylostella. Rosette plants of the G-type were fully resistant to the DBM when grown in a greenhouse or collected in the summer season, but leaves collected during the late fall were less resistant, as previously found for flea beetle resistance. The P-type was always susceptible. Extracts of resistant leaflets inhibited larval growth in a bioassay, and a growth-inhibiting fraction was isolated by activity-guided fractionation. A triterpenoid saponin (1) was isolated from this fraction and identified as 3-O-beta-cellobiosyloleanolic acid from spectroscopic data and analysis of hydrolysis products. The decrease in resistance of the G-type in the fall was correlated with a decrease in the level of 1, from 0.6-0.9 to < 0.2 micromol/g dry wt. Compound 1 was not detected in the susceptible P-type. We conclude that 1 is correlated with the variable resistance of B. vulgaris foliage to the DBM.