Figure 5

Observed and predicted profiles of PHO2 and IPS1 under Pi-depletion and repletion conditions. Panels A and B correspond to PHO2, and C and D to IPS1. Panels A and C show predicted profiles of PiOM and PsTR models, while panels B and D depict models incorporating RNA-protection. The blue dashed lines show the fold change in RNA-SEQ values from [20]. The red and black lines denote PsTR and PiOM models, respectively. The grey zones denote the period of Pi-resupply

Figure 4

<p>Fitting of different hypothesis models to PHO2 data. Panel A represents the fits of PiOM model. Panel B-F depicts the fit offered by individual hypothesis, labelled in the respective panel. Red dashed lines represent the 80% prediction interval of the respective hypothesis model. These simulations have been carried out by sampling parameter values from normal (Gaussian) distributions with means and standard deviations given from the parameter fitting in Monolix. Circle represents the qRT-PCR data. Square and triangles denotes fold change mRNA-seq data, respectively.</p

Table 1

List of AIC, -2 log-likelihood and P-value for the hypothesis models. The AIC and log-likelihood values were generated for each model while estimating parameters using MONOLIX. The relationship between the P-value and △AIC is following: P-value = Probability (χ2 k > △AIC + 2k). Here, k is the degree of freedom (i.e. the difference in T - the total number of model parameters, including both structural and statistical model). Using this relationship, P-value was calculated using Chi-squared distribution (CHIDIST) function in Microsoft Excel, while comparing the AIC value and number of parameters for each hypothesis model with the original model (PiOM)

Figure 2

Schematic representation of the molecular regulation of Pi uptake. (A) A simplified depiction of the molecular network regulating Pi acquisition. (B-F) five hypotheses to explain the observed PHO2 dynamics under Pi-deficient conditions. Panel (B-F) depicts individual hypotheses (model) in a single root cell (thick black box). Red lines and letters denote the assumed reactions and species, respectively. Each hypothesis assumed the presence of an unknown regulator Z (B-E) or R (F) acting in different manners. Protein, ligand, mRNA, complexes and Pi ions are denoted by rectangles (pink), red ellipse, parallelogram (green), squares (transparent) and blue ellipse, respectively. Pointed solid arrows denote direct interactions and fluxes, barred arrows denote inhibition or repression, and dashed lines represent indirect interactions. ø denotes endogenous production and degradation of the molecules

Le Courrier

15 octobre 18361836/10/15 (N285)

Figure 1

<p>Expression profiles of (A) PHO2, (B) IPS1 and (C) miR399 in Pi-starved rice seedling (cv. Nippobare) roots. The expression levels are relative to the +P condition at time point zero. Errors bars are SE and n = 3. Relative expression levels were normalized to that of an internal control, Os-ACTIN.</p