Potential Targets and Pathways for Rhizobium’s Mitogenic Stimulus

Abstract

Symbiotic root nodule morphogenesis begins with legume root cells’ activation by lipo-oligosaccharide “nod factors” released from compatible rhizobia (Fisher, Long, 1992 and reports in this volume). Following the animal cell paradigm, nod factor binding to a receptor activates an intracellular signaling pathway which ultimately leads to root hair curling and/or cortical cell division. It is unknown whether the ligands, receptors, and pathways differ between root hair cells that respond by curling and cortical cells that respond by dividing. It is the signaling pathway leading to cortical cell mitosis that our group is interested in understanding.