Differentiation of Bacteroids in Lotus japonicus Plants Expressing Defensin Like Peptide

Abstract

Mergaert et al. (PNAS, 2006) suggest that possible factors responsible for differentiation of rhizobia in galegoid legumes have plant origin. It was found that the bacteroid differentiation in indeterminate nodule formed in galegoid plants is distinguished than that in the other legumes and was characterized with lack of bacterial cell division ability, formation of enlarged and polyploid bacteroids. Moreover, were found genes expressed only in indeterminate but not in determinate nodules. These genes were called ncr (nodule-specific cystein-rich) and the NCR peptides have structure resembles the plant defensins with potential antimicrobial activity. It was suggested that the NCRs could be the searched plant factor responsible for bacteroid differentiation. Further, by hairy root transformation of Lotus japonicus we tried to confirm or reject this hypothesis. We found changes in morphology and characteristics of bacteroids from NCR expressed Lotus plants.