Synthesis of distinctly different sets of antimicrobial activities by elicited plant cell suspension cultures

Abstract

The aim of this study was to evaluate the potential of plant suspension cultures for the production of antimicrobial activities. The extracellular, intracellular and cell wall bound fractions of 16 heterotrophic, photoautotrophic and photomixotrophic plant cell suspension cultures each treated with nine different elicitors were tested for the elicitor dependent production of antimicrobial activities. Distinctly different patterns of bioactivities directed against a panel of human isolates including Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria as well as fungi (Candida maltosa) were identified for all except the two autotrophic cell cultures. The intracellular fractions of elicited cell cultures were more active than extracellular fractions while cell wall bound fractions showed almost no activities. The intracellular fraction of heterotrophic Lavendula angustifolia cells elicited with a preparation of Pseudomonas syringae was the most active fraction against Candida maltosa. The intracellular fraction of photomixotrophic Arabidopsis thaliana cells elicited with salicylic acid was active against all test isolates. An antimicrobial protein could be identified and partially purified from this culture. Our findings suggest that elicited plant cell cultures may present a new promising alternative source of antimicrobial proteins.