As a global community, we rely on plants to produce food, fuel, and building materials but we know surprisingly little about the biological processes that control plant growth. Therefore, I study the fundamental mechanisms that control plant growth at the cellular and genetic levels.
All organisms (including plants!) grow to a specific shape and size that is required for their survival. The size, shape, and number of cells that make up an organism dictate the overall form of the body. The processes that determine shape, size and quantity of cells are precisely regulated, yet sufficiently malleable so that life forms can respond and adapt to their environments. My research explores the molecular mechanisms that control plant cell growth. Specifically, I study how the microtubule cytoskeleton affects plant growth. My model system is Arabidopsis thaliana, which grows easily and cheaply in the lab environment. My basic research has the potential to translate into advantages in food security and biofuel production.
Microtubules are important players in cell division and expansion in all eukaryotes, and interphase microtubules are instrumental in plant cell growth. In plants, microtubules are organized into different arrays depending upon the environmental and developmental context of the cell. These microtubule arrays affect interphase cell expansion by controlling a key component of plant cell walls, cellulose. Cellulose is the load-bearing material of the cell wall and the major determinant of the direction of cell expansion. By an unknown mechanism, microtubule arrays direct the deposition and movement of cellulose synthase complexes in the plasma membrane. Interphase microtubules likely play other roles in interphase cell growth. For instance, microtubules have been implicated in the pectin deposition. In addition to interphase growth, microtubules are critical for cell division as they reorganize into arrays required for mitosis (the spindle) and cell division (the preprophase band and phragmoplast).
It is not known how microtubules are organized during interphase or cell division.
It remains a mystery how the interphase microtubules direct cell wall synthesis. My research is focused on 2 primary questions.
(1) What are the genetic components and cellular mechanisms
that organize microtubules?
(2) How do microtubules function in morphogenesis by affecting cell wall construction?