Adrienne Roeder
Assistant Professor of Plant Biology

Adrienne Roeder

Phone

607-255-4467

Address

Department of Plant Biology
Weill Hall, Room 239
Cornell University
Ithaca, NY 14853-2703

Email

Web Sites

Lab Web Site
Department Profile

Background

I am fascinated by how beautiful and complex patterns form during development. The patterning process generally requires that one cell adopts a different identity from its neighbor. Patterns are generally formed while the cells are growing and dividing, yet the coordination of cell division and growth with the process of patterning is only beginning to be understood. In plants, regulation of cell division is crucial for proper development because plant cells cannot move or even slip relative to one another. I am interested in how growth and cell division themselves contribute to the both the development and patterning of specialized cell types in plants - a process which requires analysis of development in space and time.

Research Description

The Arabidopsis sepal is a useful model system for examining the role of growth and cell division in patterning of the organ because it is accessible for imaging and manipulation. The outer epidermis of the sepal contains a characteristic pattern of giant cells, which stretch a fifth the length of the sepal, interspersed between smaller cells. This pattern of different cell sizes is tightly intertwined with cell division and growth: it arises from variation in the times when cells stop dividing and enter a specialized endoreduplication cell cycle (Roeder et al., 2010). We investigated the molecular networks underlying giant cell and small cell patterning. We found that the cell cycle inhibitor LGO (pronounced "lego", because the lgo mutant loses giant cells and is made of small blocks) promotes giant cell formation by causing cells to exit division and enter endoreduplication early. The pattern is also regulated by intercellular signaling and transcriptional regulation via genes of the epidermal specification pathway, which control the identity of giant cells. Conversely, small cell identity appears to be linked to cell cycle regulation because altering the cell cycle is sufficient to change small cell identity. In my laboratory here at Cornell, we are using genomics combined with imaging to examine in more detail the coordination of regulation of the cell cycle with giant and small cell identity. First, we are characterizing these cells identities by asking how different are the gene expression patterns of giant and small cells. Second, we are using imaging and modeling to examine how the growth of cells within the sepal is coordinated to produce the pattern. Third, we continue to investigate the molecular networks controlling giant and small cell patterning with genetics and are currently focusing on a mutant that produces ectopic large cells. Finally, we are looking at how our findings in sepals apply to other cell types and organs in Arabidopsis and other plants. The close interrelationship between patterning, growth and division means that we must understand how manipulating one affects the other two in order to engineer better crop plants or biofuels.

Selected Publications

Roeder, A.H.K., Tarr, P.T., Tobin, C., Zhang, X., Chickarmane, V. Cunha, A. and Meyerowitz, E.M. (2011) Computational Morphodynamics: integrating development over space and time. Nature Reviews Molecular Cell Biology 12, 265-273.

Jun, J.*, Fiume, E.*, Roeder, A.H.K. , Meng, L., Sharma, V.K., Osmont, K.S., Baker, C., Ha, C.M., Meyerowitz, E.M., Feldman, L.J. and Fletcher, J.C. (2010) Comprehensive analysis of CLE polypeptide signaling gene expression and over-expression activity in Arabidopsis. Plant Physiology 154, 1721-1736.

Roeder, A.H.K.*, Chickarmane, V.*, Cunha, A., Obara, B., Manjunath, B.S., and Meyerowitz, E.M. (2010). Variability in the Control of Cell Division Underlies Sepal Epidermal Patterning in Arabidopsis thaliana. PLoS Biology 8, e1000367. doi:1000310.1001371/journal.pbio.1000367

Roeder, A.H.K. (2010) Sepals. In: Encyclopedia of Life Sciences (ELS). John Wiley & Sons, Ltd: Chichester. DOI: 10.1002/9780470015902.a0002064.pub2

Cunha, A., Roeder, A., and Meyerowitz, E. Segmenting the Sepal and Shoot Apical Meristem of Arabidopsis thaliana. 32nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC`10). Buenos Aires, Argentina, September 1-4 2010

Chickarmane, V., Roeder, A.H.K., Tarr, P.T., Cunha, A., Tobin, C., and Meyerowitz, E.M. (2010). Computational Morphodynamics: A Modeling Framework to Understand Plant Growth. Annual Review of Plant Biology 61, 65–87

Harrison, C.J., Roeder, A.H.K., Meyerowitz, E.M., and Langdale, J.A. (2009). Local Cues and Asymmetric Cell Divisions Underpin Body Plan Transitions in the Moss Physcomitrella patens. Current Biology 19, 461-471.

Roeder, A.H.K. and Yanofsky, M.F. (2005). Fruit Development in Arabidopsis. The Arabidopsis Book, eds. C.R. Somerville and E.M. Meyerowitz, American Society of Plant Biologists, Rockville, MD.

Yu, Q., Moore, P.H., Albert, H.H., Roeder, A.H.K. and Ming, R. (2005). Cloning and characterization of a FLORICULA/LEAFY ortholog, PFL, in polygamous papaya. Cell Research 15, 576-584.

Lukowitz, W., Roeder, A., Parameter, D., and Somerville, C. (2004). A MAPKK kinase gene regulates extra-embryonic cell-fate in Arabidopsis. Cell 116, 109-119.

Liljegren, S.J.*, Roeder, A.H.K.*, Kempin, S.A., Gremski, K., Østergaard, L., Guimil, S., Reyes, D. K., and Yanofsky, M.F. (2004). Control of fruit patterning in Arabidopsis by INDEHISCENT. Cell 116, 843-853.

Roeder, A.H.K, Ferrándiz, C., and Yanofsky, M.F. (2003). The role of the REPLUMLESS homeodomain protein in patterning the Arabidopsis fruit. Current Biology 13, 1630-1635.