Rhizobium Attachment and Curling in Asparagus, Rice and Oat Plants Purchased

Observations by scanning electron microscopy revealed that rhizobia attach to the surface of rice protoplasts with regenerated cell walls, isolated mesophyll cells of asparagus, and root hairs of rice and oat seedlings. Those strains of rhizobia, namely Rhizobium leguminosarum biovar trifolii, Bradyrhizobium japonicum and Bradyrhizobium sp., attach to the cells of these monocots in the same manner as they attach to the host dicots tested. Escherichia coli did not attach. These results suggest that the attachment of rhizobia is not a host-specific process. When oat seedlings were infected by R. l. trifolii, hair curling was observed. The interactions between monocot plants and rhizobia is discussed in this paper.