Figure 6

Stable ncr068 T1 mutant plants inoculated with three rhizobia strains show wild-type symbiotic phenotype. Wild-type M. truncatula 2HA (WT), the deletion mutant deficient in NCR169 (dnf7-2) and ncr068 mutant plants were inoculated with S. medicae WSM419, S. meliloti FSM-MA or S. meliloti 2011 and scored for symbiotic phenotype at 5 wpi. WT and ncr068 plants showed similar growth habit but presented less effective symbiotic interaction with S. meliloti 2011 compared with the two other strains. Mutant dnf7-2 showed nitrogen deficiency with all three tested rhizobia strains. SYTO13-staining revealed a similar colonization of WT and ncr068 nodules while only bacteria in infection threads and sporadic saprophytic bacteria fluoresced in the basal part of dnf7-2 nodules.