The “Sixth Sense” of Plants

What do plants and migrating birds have in common? A sensitivity to magnetic fields. This was demonstrated by Margaret Ahmad's team¹ when they studied the effect of magnetic field on Arabidopsis thaliana plants. This effect, which can be observed in an inhibition of growth, is mediated by cryptochromes, photoreceptors sensitive to blue light. In migrating birds, perception of the geomagnetic field is also blue-light dependent and occurs in the retina, where cryptochromes are located, suggesting that the mechanism of magnetic perception in migrating birds uses the same kind of photoreceptors found in plants. Since retinal cryptochromes are highly conserved during the process of evolution, all animals might be endowed with a sixth sense, that of perceiving magnetic fields.

1. M. Ahmad et al., Planta. Epub ahead of print. Sep 6, 2006.

Contact: Margaret Ahmad,

ahmad@ccr.jussieu.fr

Pheromones of Knowledge

Rabbit pups are guided to their mother's nipple by a pheromone present in the mother's milk. Researchers from CESG¹ in Dijon demonstrated that when mixed with other olfactory stimulants, the pheromone triggers learning of the associated odors, which can then alone induce suckling. The results² suggests that pheromones, which were heretofore considered behavioral triggers and physiological regulators, might also be involved in cognitive processes.

1. Centre européen des sciences du gout: European Taste Science Center. www.cesg.cnrs.fr

2. G. Coureaud et al., Current Biology. 16: 1956-1961. 2006.

Contact : Gérard Coureaud,

coureaud@cesg.cnrs.fr