Shade avoidance responses become more aggressive in warm environments

Area of Science:

• Plant biology
• Environmental science
• Genetics

Background:

• Plants exhibit shade avoidance responses when detecting neighbors, increasing stem growth to mitigate shade.
• Understanding how environmental factors influence these responses is crucial for predicting plant adaptation.

Purpose of the Study:

• To investigate the impact of weather conditions on shade avoidance responses in *Arabidopsis thaliana*.
• To develop a predictive model for plant growth based on environmental factors and photoreceptor activity.

Main Methods:

• Generated a growth rate database under controlled conditions.
• Developed a predictive model integrating photoreceptor activity (phytochromes, cryptochromes), light, and temperature.
• Incorporated thermal amplitude effects on specific genotypes and correlated with PHYTOCHROME-INTERACTING FACTOR 4 dynamics.
• Validated the model using worldwide weather data and local growth measurements.

Main Results:

• The model accurately predicted plant growth rates in field conditions.
• Higher temperatures were predicted to enhance shade avoidance responses, particularly in warmer geographical locations and under global warming scenarios.
• Irradiance and thermal amplitude did not significantly affect shade avoidance responses.
• Local measurements corroborated the model's predictions regarding temperature effects.

Conclusions:

• Warm environments enhance shade avoidance responses in *Arabidopsis thaliana*, provided water and nutrients are not limiting.
• Projected increases in temperature due to global warming may lead to amplified shade avoidance, impacting plant competition and ecosystems.