High temperature exposure increases plant cooling capacity

SummaryPlants inhabit different environments and have evolved mechanisms to optimise growth within defined temperature ranges. In Arabidopsis thaliana, growth at high temperature (28°C) results in striking elongation of stems and increased leaf elevation from the soil surface [1–3]. Despite insights into the molecular control of these responses [1–5], their physiological significance remains unknown. Here, we analysed the impact of high temperature-mediated development on plant water use strategy. We present the surprising finding that Arabidopsis plants developed at high temperature (28°C) show increased water loss and enhanced leaf cooling capacity in these conditions, despite producing fewer leaf surface pores (stomata). Our data suggest that plant architectural adaptations to high temperature may enhance evaporative leaf cooling in well-watered environments