Epigenetic modification of rhizobial genome is essential for efficient nodulation.
CcrM is one of the solitary bacterial DNA methyltransferases which does not have corresponding restriction enzymes. We established a stable ccrM-overexpressing mutant of Mesorhizobium loti, MlccrM-OX, and performed molecular and phenotypic characterization of this strain. In the M. loti MlccrM-OX infected plants, nodulation was apparently delayed at 7 days after inoculation (dai), however, the nodules that eventually formed on the MlccrM-OX roots showed nitrogen fixing ability by at least 21 dai. These results suggest that the initial morphogenic events were affected by ccrM-overexpression and that the correct pattern of DNA methylation of the bacterial genome is not essential for plant-microbe symbiosis, but are required for efficient nodulation.
Ichida
Hiroyuki
H
Laboratory of Plant Pathology, School of Agriculture, Meiji University, Kawasaki, Kanagawa 214-8571, Japan. hi@isc.meiji.ac.jp
Yoneyama
Katsuyoshi
K
Koba
Takato
T
Abe
Tomoko
T
D019175:DNA Methylation; D044127:Epigenesis, Genetic; D016680:Genome, Bacterial; D009586:Nitrogen Fixation / Q000235:genetics*; D012231:Rhizobium / Q000235:genetics*; D053204:Root Nodules, Plant / Q000382:microbiology*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics*; D013559:Symbiosis
C098075:DNA modification methylase CcrM; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)