Cell to Plant

 
 

 

A central question in biology is how a single cell gives rise to a complex multicellular organism composed of cells with differentiated functions arranged in specific patterns and acting together to create organs with specific shapes. Higher plants face special issues in multicellular development, being tied to the location where they are born and with their cells being glued together by rigid cell walls. Thus, while animals explore and exploit their environment by moving within it, plants do so by growing into new environmental spaces. The inability to escape an unfavorable environment has resulted in the evolution of developmental strategies that allow for flexibility in responding to local environmental fluctuations. For example, a plant can grow away from the shade and into the light by a combination of directed growth (phototropism) and selectively elaborating branches. Likewise, roots can seek out pockets of moisture or nutrients through growth and branching. The outcome of these decisions has profound effects on the ability of the plant to harvest resources, to balance survival and reproduction, and to be prepared for future challenges. The presence of the cell wall means that plant cells are not free to migrate to new locations to form new associations and to create new structure, they must make decisions about their identity and growth based either on information they inherit or they receive from their neighbors next to whom they were born. Challenges in the study of plant development include identifying the mechanisms by which plant cells share developmental information, how specific pattern is created, and how the organism integrates information about resources and physiological status over time and space to make developmental decisions.
 
M. Kathryn Barton’s lab investigates the mechanisms that create the plant’s body plan, from embryo to leaf. These processes include establishment of tissue polarity and the creation and regulation of stem cell populations that give rise to the modular components of the plant body. Specific mechanisms under study include regulation by small RNA’s, the function of small Zipper proteins, and the spatial control of hormone biosynthesis and response.
 
Matt Evans’ lab studies the development and function of the gametophytes, the gamete- producing structures of flowering plants, using a combination of genetic, genomic, and cell biology tools in the model crop plant maize. Current areas of focus are how plants identify appropriate mates, how reproductive cells develop in the appropriate locations for fertilization, and how the gametophytes control development of the seeds that are ultimately the source of much of the human diet.
 
Zhi Yong Wang’s lab studies cell communication via small molecule signals, especially the hormone brassinosteroid, which modulates growth and developmental pattern. Zhi Yong takes an integrated approach employing biochemistry, proteomics, genetics and cell biology.
 
David W Ehrhardt’s lab explores the mechanisms by which cell growth is controlled and is integrated into patterns of tissue growth. These studies are conducted in collaboration with Wang lab. The Ehrhardt lab also studies plasmodesmata, channels that provide a means of cell-cell communication.
 
Wolf B. Frommer’s lab investigates the mechanisms of nutrient acquisition and long distance transport, functions central for developmental decisions for organism architecture.
 
Sue Rhee’s lab studies the decisions that plants must make to make or not make a lateral root using a combination of computational, molecular genetic and physiological approaches.
 
José Dinneny's lab examines the evolution of multicellularity enables organisms to respond to changes in much more complex ways than their single-celled counterparts.  The Dinneny lab studies how different tissues layers are involved in sensing and coordinating responses to environmental changes that impact the root system.  Here, cell-type specific approaches such as Fluorescence Activated Cell Sorting  and confocal imaging are elucidating the changes in signaling that allow the root to acclimate to stressful conditions.