3349 Kindschi Hall of Science
Courses Taught at GVSU
BIO 120 General Biology (lecture)
BIO 403 Plant Structure and Function (lecture and laboratory)
BIO 423 Plant Development and Biotechnology
CMB 150 Biotechnology and Society (lecture and laboratory)
CMB 250 Introduction to Biotechnology
CMB 405 Cell and Molecular Biology Lecture
CMB 406 Cell and Molecular Biology Laboratory
CMB 426 Nucleic Acids Laboratory
CMB 501 Scientific Communication
CMB 626 Advanced Nucleic Acids Laboratory
Signal transduction in plants
My research interests are focused in the areas of plant physiology and development. I am particularly interested in how a plant perceives a signal, whether physiological or environmental, and how such perception leads to altered growth and development.
One project involves tip growth, the type of growth that underlies 1) the formation of root hairs, which are responsible for water and nutrient uptake into ‘higher’ plants from the soil, and 2) pollen tube growth, the mechanism by which the sperm nuclei reach the embryo sac in flowering plants to result in fertilization. Both are crucial to plant success and, therefore, are crucial to animals, including humans, which rely on plants as food and oxygen sources. Both are integral to the production of agricultural crops and, therefore, food security.
I use the moss, Physcomitrella patens, as a model system for investigating tip growth as the moss grows exclusively via tip growth for a portion of its lifecycle, can be grown in culture (and so the environment can be manipulated), and is easily viewed under the microscope. We are currently characterizing an interesting random insertional moss mutant.
A number of GVSU undergraduate students have worked with this mutant so that we now know: a) that the site and possibly the rate of growth of newly established tip growth are affected by the disruption of the genome, b) the location in the genome that was disrupted when the mutant was made, c) that it appears sequence directly encoding a protein was not disrupted at this site in the mutant (suggesting that some type of regulatory sequence/function was disrupted instead), and d) that there are repeated DNA sequence elements present at the site of the disruption in the genome.
We are currently working toward addressing two questions:
• How is gene expression different in the mutant as compared to the normal moss? We are using an RNA-seq approach to this question to look at differential gene expression. This will generate a huge amount of data in the form of short ‘reads’ from the cDNAs, which then must be assembled computationally before we can compare the transcript populations from the normal and mutant moss, again using computational biology. This is a ‘big data’ project.
• By what mechanism might the repeated sequences be regulating gene expression in the normal moss? The disrupted locus contains repeated retrotransposon sequence as well as a stretch of 11 bp tandem repeats (approximately half of which were deleted when the mutant was made). A number of miRNAs are predicted to be produced from this locus and we will be using 5’RACE to detect the primary transcript (which is then processed to produce the functional miRNAs themselves) in the normal moss.
A second project involves an Arabidopsis mutant that is altered in several aspects, among them flowering and a hypersensitivity to the environment. It was originally identified due to an increased sensitivity to salt in the environment. This mutant is defective in a specific calcium-binding protein and we are working to understand the role of this protein in flowering. It appears the protein is involved in both stamen and pistil development and function in the flowers.
Both projects have involved the use of multiple approaches: genetic, cellular, molecular, and biochemical. In addition, given the direction of the moss project, computational biology will be added to the list.
B.S. in Biochemistry, University of Wisconsin-Madison
Ph.D. in Plant Physiology with Supporting Program in Biochemistry and Genetics, University of Minnesota-Twin Cities
Postdoctoral Fellow, University of Arizona
Sabbatical (2009-2010), University of Arizona
Greer, G.K., Dietrich, M.A., and J.M. Lincoln*. 2016. Ailanthus altissima stimulates legume nodulation via root exudates: a novel mechanism facilitating invasion? Int. J. Plant Sci. 177(5):400-408.
Greer, G., Dietrich, M.A., DeVol*, J., and A. Rebert*. 2012. The effects of exogenous cytokinin on the morphology and gender of Osmunda regalis gametophytes. Am. Fern J. 102 (1): 32-46.
Greer, G.K., Dietrich, M.A., Stewart* S., DeVol*, J., and A. Rebert*. 2009. Morphological functions of endogenous gibberellins in filicalean gametophytes: insights into the evolution of form and gender expression. Bot. J. Linn. Soc. 159:599-615.
Prieskorn, B. and M.A. Dietrich. A disruption in repeated sequence may be responsible for a P. patens mutant phenotype. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/15.
Kamgang, R. and M.A. Dietrich. Assessment of polar growth of a Physcomitrella patens insertional mutant. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/14.
Kamgang, R. and M.A. Dietrich. Characterization of polar growth from protoplasts of Physcomitrella patens. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/13.
Morrison, E. and M.A. Dietrich. Atypical apical growth, timing and hormone response in a Physcomitrella patens developmental mutant. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/13.
Roth, M. and M.A. Dietrich. The role of CBL10 in stamen development in Arabidopsis thaliana. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/13.
Marmion, R. and M.A. Dietrich. Abnormal initial cell formation in Physcomitrella patens. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/12.
Hansen, A. and M. A. Dietrich. Initial cell size affects the hormone response in Physcomitrella patens. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/11.
Van Brocklin, M. and M. A. Dietrich. The role of CBL10 in the development of flowers in Arabidopsis thaliana. Poster presentation at the West Michigan Regional Undergraduate Science Research Conference, Grand Rapids MI, 11/11.