Plant Thermomorphogenic Adaptation to Global Warming

Plants are capable of actively adapting to a variety of environmental signals by adjusting physiological activities, growth behaviors, and architectural morphology. Temperatures are one of the major environmental factors that extensively affect plant growth and developmental processes. A suite of signaling mediators and underlying molecular mechanisms governing plant adaptation to stressful high and low temperatures have been explored through molecular genetic approaches and global-scale gene expression screening in recent decades. Notably, it is known that ambient temperature changes even by a few degrees also profoundly affect plant developmental and morphological traits. In particular, in response to ambient warm temperatures, plants exhibit distinct morphological adjustments, such as stem elongation, increase of leaf hyponasty, and formation of small, slender leaves, which are collectively termed thermomorphogenesis. Plant thermomorphogenesis is intimately associated with global warming, which represents a steady increase of the average global temperatures and is emerging as a world-wide ecological concern because of its impacts on plant vegetation and crop productivity. In this minireview, we summarize recent progress in the field and discuss practical insights into how plants cope with temperature changes to sustain optimal growth and adaptive behaviors.