Production de composés indoliques rhizogènes par le ver de terre Lumbricus terrestris

Abstract

In vitro application of total gross extract of earthworms (Lumbricus terrestris) in diverse dilutions stimulates rhizogenesis in young bean plants (Phaseolus vulgaris). The observed effect is similar to that of indol acetic acid, a well-known growth enhancer in plants, used here as a control in various concentrations. Fragmentation of worm extract by column chromatography results in three groups of fractions. Only the polar group of fractions has a significant rhizogenous effect, which is, however, inferior to that observed in the presence of total gross extract of worms or of indol acetic acid. Gross extract analyses using thin layer chromatography, with appropriate chromatography systems and reagents, revealed that indol acetic acid is not present, but is probably replaced by other indol-derived substances that have a neutral to basic chromatographic behaviour. These presumed indol-derived substances are identified as methyl-tryptophane, serotonin, and hydroxy-indol acetic acid. Analyses using mass spectrometry combined with gas chromatography, following fragmentation and purification of the group of rhyzogenous fractions, have revealed the presence of hydroxy-indol carboxylic acid, which seems to take the form of several isomeres.[Journal translation]