Marine plants may polarize remote Fucus eggs via luminescence

Fucus zygotes can be polarized by many environmental vectors. These include those created by pieces of all the intertidal marine plants tested. At distances of up to 5-10 mm away from such pieces, Fucus zygotes form their intitial outgrowths or germinate towards them. Earlier papers had inferred that this so-called 'thallus effect' is mediated by diffusing molecules. The present reinvestigation indicates that the thallus effect is exerted by influences that can go right through glass barriers. This indicates action via luminescence. This luminescence may come from bacteria growing in biofilms on the similar surfaces of these otherwise unrelated source plants. Moreover, this directive luminescence is inferred to lie at wavelengths in the red or longer and may take the form of more or less coherent biophotons.