Mycorrhizas shape the evolution of plant adaptation to drought

Abstract

O_LIPlant adaptation to drought facilitates major ecological transitions, and is likely to play a vital role under looming climate change. Mycorrhizas can influence the physiological capacity of plants to tolerate drought. Here, I show how mycorrhizal strategy and drought adaptation shape one another throughout the course of plant evolution. C_LIO_LITo characterize the evolutions of both plant characters, I applied a phylogenetic comparative method using data of 1,638 extant species globally distributed. C_LIO_LIThe detected correlated evolution unveiled gains and losses of drought tolerance occurring at faster rates in lineages with an ecto- or ericoid mycorrhizal strategy, which were on average about 15 and 300 times quicker than that in lineages with the arbuscular mycorrhizal and naked root (non-mycorrhiza or facultatively arbuscular mycorrhiza) strategy, respectively. Among mycorrhiza shifts, the arbuscular mycorrhiza losses in drought sensitive lineages were more frequent than any symbiont switching or other mutualism breakdown. C_LIO_LIMy study suggests that mycorrhizas play a key facilitator role in the evolutionary process of plant adaptation to critical changes in water availability across global climates. C_LI