Fig 6. Plant phosphate concentration is negatively correlated with plant biomass when phosphate is the limiting factor.

Phosphate concentrations of plants growing under low (20 μm) or medium (100 μM) phosphate are highly negatively correlated with plant biomass (Pearson’s correlation is -0.58 and -0.53 respectively and p-value <10⁻⁶). By contrast, under high phosphate level (750 μM), no significant correlation is observed between plant biomass and plant phosphate concentration. Each dot represents a single plant from different experiments. Phosphate concentration is calculated relative to wt roots phosphate concentration on 20 μM phosphate. Colored lines and colored shades represent linear regression and 95% confidence intervals respectively.