Evolution of two gene networks underlying adaptation to drought tolerance in the wild tomato Solanum chilense

We conduct a transcriptome analysis of plants under normal and drought experimental conditions to understand the evolution of drought-response gene networks. We identify two main regulatory networks corresponding to two typical drought-responsive strategies: cell cycle and fundamental metabolic processes. We estimate the age of the genes in these networks and the age of the gene expression network, revealing that the metabolic network has a younger origin and more variable transcriptome than the cell-cycle network.