All living organisms utilize both exogenous and endogenous cues to regulate their metabolism, growth and development. Plants, given their ‘fixed in the ground’ (sessile) nature are especially sensitive and responsive to their environment and exhibit highly plastic developmental programs. Unlike animals where the body plan is established almost entirely during embryogenesis, plant form and function is mostly elaborated post-embryonically. This dominance of post-embryonic patterning and growth affords plants the plasticity they need to modify their growth, morphology and behavior to even subtle and rapid changes in their environment. Because environmental inputs are numerous and ever changing, responsiveness of an organism is highly integrated, where multiple input signals are ‘sorted’ and transduced in an efficient manner to give rise to proper adaptive responses. Our laboratory is interested in understanding such integrated signal-response systems from molecules to functional ecology, and employ Arabidopsis thaliana as a model for most of our studies.

One adaptive response we are particularly interested in is phototropism. Phototropism is a classic example of plant ‘movement’ that is both robust and rapid, and is genetically amenable in Arabidopsis. Our studies have shown that the plant utilizes multiple photosensory pathways to monitor the light environment, and that these pathways are integrated with a number of endogenous hormone response pathways to elicit an adaptive phototropic response. Our current research foci on phototropism include: understanding how the primary phototropic photoreceptor, phototropin 1 (phot1), initiates signal transduction; unraveling the role of protein phot1 ubiquitination, endocytosis and degradation in early signaling events; determining the transcriptional outputs of the signaling process and how their encoded proteins affect physiological outputs; developing a 3D temporal-spatial map of the phototropic response system in planta; and elucidating how phototropic responses impact plant ecology and evolution under natural conditions.