Identification and Phytotoxicity of 3-methylthiopropanoic and Trans-3-methylthiopropenoic Acids Produced in Culture by Xanthomonas campestris pv. vitians

• Published in: Journal of phytopathology Vol. 144; no. 6; pp. 325 - 329
• Main Authors: Scala, F., Zoina, A., Coppola, L., Capasso, R., Lorito, M., Evidente, A.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.1996; Blackwell
• Subjects: Bacterial plant pathogens; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Phytopathology. Animal pests. Plant and forest protection; Systematics. Structure, properties and multiplication. Genetics; Pseudomonadales; Plant pathogen; Metabolite; Toxicity; Enethiol sulfide; Organic sulfide; Pathogenicity; Ester; Phytotoxicity; Carboxylic acid; Trans stereoisomer; Bacteria; Pseudomonadaceae
• ISSN: 0931-1785; 1439-0434
• DOI: 10.1111/j.1439-0434.1996.tb01537.x

Two phytotoxic metabolites were isolated from culture filtrates of Xanthomonas campestris pv, vitians, the causal agent of lettuce leaf spots and headrot. The two compounds were identified as 3‐methylthiopropanoic (1) and trans‐3‐methylthiopropenoic (2) acids by chemical and spectroscopic methods. Toxic effects of the two compounds on leaf tissues and protoplasts of lettuce and cabbage were investigated. Solutions of 1 and 2 induced chlorosis and necrosis on lettuce leaves at minimum concentrations of 300 and 50 μg/ml, respectively. Infiltration in cabbage leaves did not produce any symptoms. The LD50 values for 1 and 2 against lettuce protoplasts were 15 and 16 μg/ml, respectively. Activity of the two metabolites against cabbage protoplasts was very low (LD50 > 500 μg/ml).