An article in the Chronicle of Higher Education* recently described a debate about the connection between teaching and research.  One policy-maker was quoted as saying,

"The great researchers aren't ... super narrowly focused on the answers.  They're excited by great questions. Teaching is really about getting students to struggle with and explore those questions."

This idea – that teaching and research are crucially and necessarily linked – is central in my learning and teaching career.  My aim is that students in my courses, as well as those participating in research with me, will gain their own excitement for great questions!

Current Research - Trinity College, Hartford, CT: The Bush lab studies the way in which plants respond to environmental stresses. Stresses like drought, heat, or toxic minerals like aluminum in the soil can make it difficult for a plant to grow, and - unlike animals - a plant must survive and reproduce in the same location it was originally planted. Crop plants, like tomato, have been domesticated to carry genes that are important for farming and high yield, but the plants may not carry the gene variants that can help them survive under environmental stresses. Wild South American relatives of tomato and colorful heirloom varieties of domesticated tomatoes harbor naturally occurring genetic diversity, which can make them more tolerant of stressful conditions. 

In the Bush lab, we study the physiology, or the growth traits, of plants under normal conditions compared to their growth in the presence of the toxic element aluminum. We also examine how differences in plant physiology are underlain by genetic variation. Students can examine growth of tomato plants and the model plant Arabidopsis thaliana, the effect of stress hormones, and the degree to which aluminum stress impacts different plants. We also study the genes involved in aluminum tolerance, using mutants and different species or varieties of tomato. We can use microscopy to show the levels of aluminum present in the roots of tomatoes under different conditions. We can create genetically modified plants carrying more or less tolerant alleles of aluminum-related genes; we can sequence DNA to find new gene variants; we can use bioinformatics to explore global gene expression patterns; and we can use quantitative PCR to examine the levels of a gene in different varieties of plants.

A new project to explore in the Bush is the types of chemical compounds exuded by tomato roots in the presence of aluminum - what do the roots release to help protect themselves from toxic aluminum? Can we find natural variation in this root exudate response? Students in the Bush lab will work on these types of projects and related ones, to help define the way tomato plants respond to aluminum in their environment. 

Previous Research - Macalester College, St. Paul, MN: The role of ALS1 in aluminum sensitivity in wild and domesticated tomatoes. 


Natural variation in response to environmental stressors exists between wild (Solanum pennellii) and domesticated (S. lycopersicum) tomato species. We are using a S. pennellii introgression population to study the effects of aluminum stress on roots. The ABC half-type transporter ALS1 is thought to be involved in aluminum sequestration in the root; an introgression line carrying the S. pennellii allele of ALS1 allows us to ask about the effect of specific amino acids on the function of ALS1 within tomatoes. Using RNAseq data, we can examine the effect of aluminum on gene expression in tomato roots.  

Previous Research - Maloof Lab, University of California, Davis: A shade-grown tomato introgression population implicates cell wall regulation and auxin signaling in overall and organ-specific shade responses.

Wild tomato species, such as Solanum pennellii, are adapted to growth in wide-open spaces with constant access to sunlight; in competition for sunlight, S. pennellii has a strong shade avoidance response (SAR). In contrast, the crop plant S. lycopersicum grows in close proximity to its neighbors, and has reduced SAR. In this study, the natural genetic variation for shade tolerance that exists between these two species was examined using a S. pennellii introgression population. We used a combination of phenotypic and RNAseq transcriptome analyses to identify genes and regions of the genome responsible for strong shade response or shade tolerance. In this way, we show that the growth plasticity seen in response to shade treatment requires early expression of specific auxin signaling and cell wall expansion genes. Our findings may ultimately be useful when considering tomato breeding choices, in order to develop plants tolerant of shade that still maintain high fruit yield.

Previous Research - Krysan Lab, University of Wisconsin, Madison: Functional genomic analysis of MAP kinases in Arabidopsis thaliana

We examined the role of 20 MAP kinase genes and 3 MAPKK kinase genes in the model plant Arabidopsis thaliana using reverse genetics tools, including transgenic insertional mutants, and forward genetics tools, including iTILLING, a personalized approach to identification of mutations in specialized genetic backgrounds.  qPCR and high-throughput genotyping methods were utilized to create and begin phenotypic analysis of mutant plants carrying up to 17 T-DNA insertions in MAPK genes.  With the aid of high-resolution melting analysis, we identified of mutant Arabidopsis plants carrying point mutations in one, two, or three tandemly duplicated MEKK genes, allowing characterization of unique and overlapping roles of each.

* Berrett D (2011) Want to be a good researcher? Try teaching.  Chronicle of Higher Education,