A METHOD FOR STUDYING CHEMOTAXIS IN NITROGEN-FIXING CYANOBACTERIUM-PLANT SYMBIOSES

A modified version of the Pfeffer technique has been developed to demo nstrate a strong chemotactic response of hormogonia from the filamento us nitrogen fixing Cyanobacterium Nostoc sp. towards exudates of one o f its symbiotic partners, the liverwort Blasia pusilla (L.) This techn ique offers the potential to study this mutualistic symbiosis further, in particular at those primary stages of the interaction which have n ot been investigated previously. It will also enable other plants, for example wheat, to be screened for the production of chemotactic signa ls and thereby raise the possibility of extending the host-range of th is nitrogen fixing cyanobacterium. (C) 1996 Academic Press Limited