Plants transitioned from an aquatic to a terrestrial lifestyle during
their evolution. On land, drought became one of the major problems they
encountered, as it impacts correct cell functioning necessary to support
life. The evolution of morpho-physiological and molecular adaptations to
cope with and tolerate drough was undeniably useful to survive on land.
Some of these adaptations appeared repeatedly in phylogenetically
distant species, showing a signature of convergent evolution. Details of
this convergent evolution are now being assessed thanks to recent
developments on high throughput phenotyping and whole genome and
transcriptome sequencing. Phylogenomic (comparative genomic) and
comparative transcriptomic analyses are revealing complex,
well-coordinated and intricate gain and loss of genes and co-option of
gene regulatory networks underlying cell and tissue specific adaptations
to moderate and extreme drought in phylogenetically distant species.
Here we review recent research on signatures of convergent evolution of
regulatory networks underlying carbon concentrating mechanisms such as
C4 and CAM photosynthesis, desiccation tolerance in seeds and
resurrection plants, and impermeabilization of root exodermis.