THE PLANT POLYPHENOL CAFFEIC ACID AFFECTS LIFE TRAITS DIFFERENTLY IN THE NEMATODE CAENORHABDITIS ELEGANS AND THE CLADOCERAN MOINA MACROCOPA

摘要

During decomposition and humification of leaf litter, soil and freshwater organisms may be exposed to plant poly-phenols and affected by them. If non-specific biotic interactions of these compounds were considered so far, only adverse impacts have been in the focus. Yet, potential beneficial effects remain obscure. In this contribution we followed the hydrological path of the water-soluble poly-phenol, caffeic acid (CA), by testing a soil and a freshwater model animal. Caenorhabditis elegans and Moina macrocopa were exposed 0, 50, 100, 200, and 300 μM CA and lifespan and lifetime offspring output were recorded. With M. macrocopa, even 500 μM were applied. In C. elegans, lifespan extension and a reduction of offspring numbers was observed; whereas M. macrocopa responded with reduced lifespan, but increased offspring numbers. Potential antimicrobial activity of CA did not apply for the lifespan extension in C. elegans. The reaction patterns of both model animals are discussed in the light of two actual hypotheses: hormesis and disposable soma theory. Hormesis can be excluded, since with both animals one life-trait parameter has been adversely affected. The disposable soma theory implies the optimal allocation of metabolic resources between somatic maintenance and reproduction. Both model organisms are r-strategists with the potential of developing dia-pausing stages. Hence, the different reaction patterns do not seem to be a specific optimization of the niche exploitations, but to mirror the intrinsic variability of resource allocation of different species.