Michael F. Thomashow

My early research was directed primarily towards understanding how the soil bacterium Agrobacterium tumefaciens causes the formation of tumors on plants. Along with my colleagues, I found that a small portion of the Agrobacterium genome, the T-DNA, is transferred into the plant cells where it is integrated into the nuclear genome and the genes that it encodes become expressed. Further studies established that two genes carried on the T-DNA encode enzymes mediating the synthesis of auxin, a potent plant hormone that has a key role in stimulating cell proliferation. More recently, research in my laboratory has focused on understanding the mechanisms that plants have evolved to tolerate abiotic stresses. Most of our effort has centered on the cold acclimation response, the process whereby certain plants increase in freezing tolerance in response to low, nonfreezing temperatures. We have recently described a small family of regulatory and target genes in Arabidopsis, comprising the CBF cold response pathway, which is activated at low temperature and has a central role in cold acclimation and freezing tolerance. The goals of our current research are to determine the nature of the molecular "thermometer" that controls expression of the CBF pathway and to construct a low-temperature gene "wiring diagram" that identifies the transcription factors and gene regulons with critical roles in life at low temperature.