Plants under pressure

Abstract

Altitudinal gradients may be seen as a proxy for temperature gradients, and thereby can be used in climate change studies to understand an organism’s response to different temperature conditions. However, altitudinal change is also associated with changes in atmospheric pressure and oxygen and carbon dioxide partial pressures, which for plants, can lead to physiology and growth impacts. To better understand the influence of pressure on plant growth and fitness, Carla Arce from the University of Neuchâtel and Zoe Bont from the University of Bern, both in Switzerland, and colleagues in Switzerland and Brazil grew and observed common dandelion (Taraxacum officinale) under otherwise controlled conditions at four experimental stations situated between 526 and 3,450 m above sea level. Their work revealed reduced root growth and root:shoot ratios under lower pressure, as well as higher production of the defence metabolite TA-G under higher pressure, which was particularly pronounced in populations originating from low-altitude environments. Overall, the work has important implications for the interpretation of climate change studies that assess plant responses to temperature across altitude gradients, while suggesting potential challenges for species that track warming by migrating up mountains. TAM