Overlapping Plant Signal Transduction Pathways Induced by a Parasitic Nematode and a Rhizobial Endosymbiont

• DOI: 10.1094/mpmi.2001.14.10.1168
• Publication Date: 2007-05-11T09:11:25Z
• Authors: Hinanit Koltai; Murali Dhandaydham; Charles Opperman; Judith Thomas; David Bird
• Keywords: Medicago truncatula; Sinorhizobium meliloti

Root-knot nematodes and rhizobia establish interactions with roots characterized by the de novo induction of host structures, termed giant cells nodules, respectively. Two transcription regulators, PHAN KNOX, required for establishment meristems were previously shown to be expressed in tomato cells. We isolated orthologues KNOX (Mt-phan Mt-knox-1) from model legume Medicago truncatula, established spatial distribution their expression situ. confirmed that Mt-phan Mt-knox-1 are lateral root initials nematode-induced showed they nodules induced Sinorhizobium meliloti. Expression both genes becomes spatially restricted as develop. further examined nematode feeding sites two involved nodule formation, ccs52 (encodes a mitotic inhibitor) ENOD40 an early, nodulation mitogen), found transcripts present around Medicago. Collectively, these results reveal common elements responses mutualistic parasitic plant endosymbionts imply overlapping regulatory pathways lead nodules. discuss context phytohormones parallels between beneficial symbiosis disease.