Expression analysis of defense genes ofLotus japonicus in symbiosis with Mesorhizobium loti

Abstract

Nitric oxide (NO) and reactive oxygen species (ROS), that are signal molecules in plant defense system, are produced in host plant cells by inoculation of rhizobium. The mutant of AtNOA1, which relates in nitric oxide synthesis in Arabidopsis thaliana, exhibit lower nitric oxide level than that of wild type and declined defense response against pathogens. We cloned and analyzed expression profiles of LjNOA1, the homolog of AtNOA1 of Lotus japonicus. When the expression of LjNOA1 was compared with, the expression of plants under symbiotic condition is higher than that of the plants with nitrogen fertilizer in all the tissues of plants. The higher expression of LjNOA1 may enhance the defense system of host plants L. japonicus.