Conifer species adapt to low-rainfall climates by following one of two divergent pathways.

ABSTRACT: Water stress is one of the primary selective forces in plant evolution. There are characters often cited as adaptations to water stress, but links between the function of these traits and adaptation to drying climates are tenuous. Here we combine distributional, climatic, and physiological evidence from 42 species of conifers to show that the evolution of drought resistance follows two distinct pathways, both involving the coordinated evolution of tissues regulating water supply (xylem) and water loss (stomatal pores) in leaves. Only species with very efficient stomatal closure, and hence low minimum rates of water loss, inhabit dry habitats, but species diverged in their apparent mechanism for maintaining closed stomata during drought. An ancestral mechanism found in Pinaceae and Araucari

SUBMITTER: Brodribb TJ 

PROVIDER: S-EPMC4210017 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature