Fig. 6

P accumulation responds to P and N availability. a root and b leaf P concentration (ppm dry mass) of 25-day-old maize seedlings grown across five levels of N availability (N5 to N1, high to low) and high (green points and trace) and low (yellow points and trace) levels of P availability. Large points show treatment medians; small points show individual (4) biological replicates. Dashed lines show best fit from a multiple regression model. Asterisks represent statistical significance of model terms (p value ≤0.001 ***; 0.001–0.01 **; 0.01–0.05 *). N, P main effect of N and P, respectively. NP, NxP interaction term. Lowercase letters indicate significant (p < 0.05) pairwise differences (Tukey)