Shade avoidance responses become more aggressive in warm environments

FISCHBACH, PATRICK; CASAL, JORGE J.; ROMERO?MONTEPAONE, SOFÍA; SELLARO, ROMINA; POODTS, SOFÍA; ZURBRIGGEN, MATIAS D.

PLANT, CELL AND ENVIRONMENT (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020

0140-7791

When exposed to neighbour cues, competitive plants increase stem growth to reduce the degree of current or future shade. The aim of this work is to investigate the impact of weather conditions on the magnitude of shade-avoidance responses in Arabidopsis thaliana. We first generated a growth rate database under controlled conditions and elaborated a model that predicts daytimehypocotyl growth as a function of the activity of the main photo-sensory receptors (phytochromes A and B, cryptochromes 1 and 2) in combination with light and temperature inputs. We then incorporated the action of thermal amplitude to account for its effect on selected genotypes, which correlates with the dynamics of the growth-promoting transcription factor PHYTOCHROMEINTERACTINGFACTOR 4. The model predicted growth rate in the field with reasonable accuracy.Thus, we used the model in combination with a worldwide dataset of current and future whether conditions. The analysis predicted enhanced shade-avoidance responses as a result of higher temperatures due to the geographical location or global warming. Irradiance and thermal amplitude had no effects. These trends were also observed for our local growth rate measurements. We conclude that, if water and nutrients do not become limiting, warm environments enhance the shade avoidance response.