Summary of groups identified following hierarchical clustering of expression data.

adistinct patterns of gene expression were identified following hierarchical clustering [42] of the significantly differentially expressed genes (Figure S1).bAverage expression profiles were calculated in GeneSpring for each group of genes across the time series. Column headers represent time (d) relative to Pi withdrawal, with Pi being re-supplied after 28 d. Symbols: ↑ average group gene expression up-regulated more than 1.5-fold, ↓ average group gene expression down-regulated more than 1.5-fold, - average group gene expression between 1.5 down-regulated and 1.5-fold up-regulated, i.e. no change.cTop five Gene Ontology terms present in each group that appear more often than would be expected by chance, identified using GeneSpring's GO Ontology Browser.