Figure 4

NCR expression during nodule senescence. (A) Scatter plot of the expression of 334 NCRs (blue) and 8 senescence marker genes (red) in 14 dpi nodules (x-axis) and 16 dpi nodules, which have been treated before harvest with nodule senescence-inducing nitrate for 2 days (y-axis) [20]. (B) Scatter plot of the expression of 334 NCRs (blue) and 8 senescence marker genes (red) in 20 dpi nodules (x-axis) and 20 dpi nodules, which were treated for 24 h with phosphinothricin before harvest (y-axis) [29]. (C) Scatter plot of the expression of 334 NCRs (blue) and 8 senescence marker genes (red) in hand-sectioned nodule sample III (x-axis) and in hand-sectioned nodule sample IV (y-axis). The scale of all axes is the same and is 25,000 at maximum. The red line in the three graphs indicates a ratio of 1 between the two conditions that are compared. The probe-sets for the senescence marker genes, encoding cysteine proteinases, a chitinase, a nuclease, a nucleoside transporter and a metal-nicotinamide transporter, are provided in Additional file 1: Table S1.