Interaction of light and temperature

The mechanisms by which organisms alter their growth and development in response to changes in their ambient environment are largely unknown. Most plant organs exhibit remarkable phenotypic plasticity in response to their local environment. The stem displays such plasticity in response to light and temperature. For example, in the shade avoidance response, the plant competes against neighboring plants by elongating its stem to secure access to sunlight. In the thermomorphogenesis response, the stem elongates in response to warm temperatures, thus increasing airflow between leaves. However, it is poorly understood how light and temperature cues interact to affect plant growth. We showed that shade and warm temperature interact synergistically when presented simultaneously and promote rapid stem elongation in several plant species. We found that this growth effect depends on PHYTOCHROME-INTERACTING FACTOR (PIF), auxin signaling, promoted mainly by shade, and the activation of an unknown factor (factor X) by warm temperature which boosts auxin activity.

We study the key signaling pathways and mechanisms that link information from the environment to changes in plant growth. We will study the nature of "factor X" in Arabidopsis and tomato. In addition, we study how the response mechanism to shade and warm temperature differ between organs within a plant and between plant species.