FIGURE 1.

Inoculation with Sinorhizobium meliloti Sm2011 reduced Pst DC3000-induced mitogen-activated protein kinase (MAPK) phosphorylation in Medicago truncatula A17 roots and leaves. (A) S. meliloti Sm2011 specifically reduced Pst DC3000-induced MAPK phosphorylation. The roots or leaves of M. truncatula were treated with cell suspensions of S. meliloti Sm2011 (OD₆₀₀ = 0.5), Pst DC3000 (OD₆₀₀ = 0.5), Mesorhizobium loti MAFF303099 (OD₆₀₀ = 0.5), a mixture of S. meliloti Sm2011 and Pst DC3000 (both concentration equivalent to OD₆₀₀ = 0.5) or a mixture of M. loti MAFF303099 and Pst DC3000 (both concentration equivalent to OD₆₀₀ = 0.5) for 15 min. Immunoblot analysis was performed using anti-phospho-p44/p42 MAPK antibody. The analysis of β-actin was performed as a loading control. (B) Intensity of the western blot signals (A) were quantitatively determined by ImageJ software (normalized MAP kinase levels of actin). The error bars represent SD values obtained from three biological replicates. Different letters indicate significant differences as determined by a t-tests (p ≤ 0.05).