Fig. 2
(Panel a) Relationships between accumulation of total nitrogen (Nt) and N allocation to NF-pools. Axillary shoot tips of Petunia hybrida at excision time, Nt allocation to metabolic NF-pools classifying amide-N, amino-N, insoluble protein-N and the sum of NF-pools in response on three levels of Nd fertilization to donor plants (N low, N high, N excess). Linear correlation coefficients for nitrate-N (r = 0.91), amide-N (r = 0.88), amino-N (r = 0.74), insoluble protein-N (r = 0.96) and sum of NF-pools (r = 0.99) all n = 24, p < 0.05. (Panel b) Increase in shoot dry mass per cutting during AR formation (hpin) in response to two levels of Nd fertilization to donor plants (N low, N high) and to a pre-rooting dark exposure of cuttings (dark exposure - open circled symbols, no dark - squared symbols). Vertical bars represent 95 % confidence intervals of mean values and different lower-case letters indicate significant differences. Further details of experiments, regression equations and statistics are presented in methods and with Additional file 1) Experiments of nitrogen preconditioning of cuttings, Additional file 2) Explanation of experimental designs for statistical analyses and Additional file 3) Supplemental data of figure 2 for Panel a: Exp. 1: NF-N, and Panel b: Exp. 9: NF-NDCR, respectively