My Scientific Research
 

  

 

 
 
 
 
 
 
 
 
 
 

 
 

 

 

  

My professional interests focus on the general area of plant developmental biology. I started my scientific career at Purdue University in the lab of Dr. Jeff Bennetzen where I learned a lot about DNA preps and did a small project to develop LD50s for various stresses on corn seedlings. After graduating with a BS in biology and a minor in Genetics, I was accepted as a graduate student at Washington State University in the Lab of Dr. Mike Thomashow. My initial project was to identify changes in gene expression and protein accumulation/phosphorylation that might be brought about by cyclic AMP in plants. However, shortly after starting this project, Mike was offered and took a job at Michigan State University. Consequently I followed him there and changed my project to studying cold-regulated gene expression. After graduating in 1993, I was offered a Post doc  position with Dr. Lynn Dahleen at the Northern Crop Science Lab [a USDA/ARS facility in Fargo ND]. There, I was charged with identifying molecular markers associated with the durable stem rust resistance gene RPG1. After a successful post doc, I was hired by the USDA/ARS in the Plant Science Research Unit of the Bioscience Research Lab in Fargo ND. Currently, I investigate the signal transduction pathways that control growth of underground adventitious buds of a perennial weed known as leafy spurge (Euphorbia esula). For those unfamiliar with this weed, leafy spurge is an invasive perennial weed that infests the Northern Great Plains of the U.S. and Canada. This weed maintains its perennial growth pattern and escapes many control measures through the formation and maintenance of numerous adventitious buds on its extensive root system. These buds, once formed, enter a quiescent state and do not resume growth until the shoot is killed or the root system is disrupted.

The primary goal of our research is to characterize and understand the signals and signaling pathways that control growth of these underground adventitious buds using molecular and genomics based approaches. Most recently we have been using microarray analysis to identify key signaling pathways that are differentially activated when the buds transcend from dormant to a growing-competent state or back again. Additionally, we have cloned and are studying the regulation of key genes involved in bud growth and development such as CYCLIN D3, SHOOTMERISTEMLESS, and KRP3. We have also begun investigating the possibility that flowering signals regulate bud dormancy. In 2003, we published that hypothesis in our TIPS paper and it has recently been confirmed to be the case in poplar and peach. Consequently we have cloned and are studying the regulation of and role that genes such as FLOWERING LOCUS T (FT) and DORMANCY AFFECTING MADS-BOX (DAM) genes play in induction, maintenance and loss of endodormancy (the dormancy that generally occurs in perennial buds in the fall).

Another project that has recently sparked our interest is the interaction between weeds and crops. Although it is well known that weeds reduce crop yields, not much is known about the mechanisms which cause yield reduction. Thus, we have begun a collaboration with Dr. Sharon Clay at South Dakota State University to use microarrays analysis to study the changes in gene expression that occur in both corn and velvetleaf (Abutilon theophrasti- an annual broad leaf weed) when these plants are grown in monoculture or in competition with one another. This has resulted in identifying numerous genes that appear to be weed-inducible. We are developing reporter gene constructs to begin identifying cis-acting regulatory elements that should provide a link to genes and proteins involved in how crops detect and respond to weeds. Since a recent bit of work has clearly demonstrated that weeds negatively impact crop growth and yield even when they are not in direct contact or competition, our goal is to make crops that are blind to weeds.