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 how light acts as an environmental regulator of such integrated signal-response systems from molecules to functional ecology, and employ Arabidopsis thaliana as a model for most of our studies.

Though our laboratory has historically focused on phototropism as a model response, we have recently changed focus to examine the role of light in the modulation of reactive oxygen species (ROS) production and signaling. We are working to elucidate the molecule mechanisms by which phytochrome B (phyB), one of the five red/far-red photoreceptors in Arabidopsis, is integrated into the ROS responses to a variety of stress. Two elements of the ROS stress responses are of particular interest: 

1. How does cytoplasmic-localized phyB regulate the rapid production of ROS via plasma membrane-localized NADPH-oxidases (respiratory burst oxidase homolog, RBOH; termed NOX in animals)? 
2. How does nuclear-localized phyB regulate the long-term adaptation response that requires altered patterns of gene expression, and allows the plant to withstand exposure to subsequent stresses? 

We are tackling these questions in collaboration with Profs. Ron Mittler (Division of Plant Sciences), Yosef Fitchman (Tel Aviv University), and Johanna Morrow (Westminster College; and Mizzou Biology PhD).