Meet the Faculty

Gary Stacey

Professor
Division of Plant Sciences

Phone: 573-884-4752
Fax: 573-884-9676
E-mail: StaceyG@missouri.edu
Address: 271E Life Sciences Center
Web site: Gary Stacey 's Laboratory

Education
B.S., Biology, Bowling Green State University
Ph.D., Microbiology, University of Texas, Austin

Description
Host-microbe interactions
The major focus of research in the Stacey lab is the symbiosis between the bacterium Bradyrhizobium japonicum and its host plant, soybean. The result of this interaction is the establishment of a novel organ, nodule, on the root of the host. Inside this organ, B. japonicum fixes atmospheric nitrogen, which the plant can use. The lab's work on this symbiosis focuses both on the symbiont and the plant host. With regard to the bacterium, they are largely focusing on the regulation of the nodulation genes required for plant infection and establishment of the symbiosis. Regulation of these genes is complex. For example, they recently discovered a novel quorum (population density) signal bradyoxetin that controls nodulation gene expression in planta. This work may have broader relevance to other bacteria, including animal pathogens, which have an intracellular growth habit. Plant perception of lipo-chitin nodulation signals, produced by the bacterium, is essential for induction of de novo organogenesis, leading to nodule formation. The lab's research is focused on plant recognition of this molecule and the signal transduction pathways leading to nodule development. This work has led them to a general interest in chitin recognition in plants. For example, chitin, released from the cell wall of pathogenic fungi, is a known elicitor of defense responses in plants. They are investigating this phenomenon using DNA microarray and proteomic approaches.

Peptide transport in plants
There is a growing body of information implicating peptides as circulating hormones in plants. This is consistent with the major role that peptides play in regulating growth and development in animals. The lab's contribution to this area focuses on the role of peptide transporters in the growth and development of the model plant Arabidopsis thaliana. They have identified peptide transporters in two families: PTR, which transport di- and tripeptides, and OPT, which transport tetra- and pentapeptides. In both cases, disruption of peptide transporter expression (e.g., through antisense expression or mutation) results in severe defects in seed and embryo development. Their goal in this research is to define the role peptide transporters play in plant growth and development, to define their substrates and to elucidate the regulation of these interesting proteins.

Soybean genomics and biotechnology
As part of the growing family of researchers at MU who are interested in soybean biology, the Stacey laboratory is contributing to the development of soybean genomic research. The goal of this research is to identify genes and traits that can benefit soybean agriculture. For example, at MU, the lab is developing, in collaboration with other laboratories, first-rate facilities for high-throughput molecular breeding of soybean and transformation capabilities for creating transgenic soybean with improved agronomic and/or nutritional traits.