Dr. Jeff Long
Plants develop along a polar axis, with an apical shoot system at the top and a basal root system at thebottom. The shoot system is responsible for all of the above ground portions of the plant such as leaves, branches and flowers, and is the site of photosynthesis. The root system lies below the ground and provides water and nutrients to the plant. This shoot/root system develops early during plant embryogenesis and is fully formed in the mature seed.
My lab’s research is focused on how this root/shoot system forms. In other words, we are interested in how a plant embryo develops apical/basal polarity. We are taking a genetic approach to answer this question using the plant model organism Arabidopsis thaliana. By isolating mutants that are disrupted in this process and then cloning the genes responsible, we are gaining insight into the molecular mechanisms the plant uses to determine its polarity. One mutant we have isolated, topless, transforms the apical shoot system into a second, basal root system, giving rise to a seedling with roots at both poles. We have cloned the gene responsible for this transformation and find it encodes a protein that prevents the transcription of root specific genes in the shoot system. We are currently cloning other genes that are involved in the same process, and have found that two of them are highly conserved with genes found in animals and humans.