UC Riverside

Proper cell division orientation is an important component to plant and animal growth and development. In contrast to animal cells which divide through the constriction of the contractile ring, plant cells divide through the expansion of a microtubule and actin structure, the phragmoplast, to a division site specified at the cell cortex. Plant cells are encased in a semi rigid cell wall and do not rotate or migrate, thus coordination of division site structures with the division site is very important. In Chapter 1, I discuss temporal, genetic, and synthetic redundancies that ensure plant cell division planes are positioned correctly. In Chapter 2, I examine and characterize the role of cortical telophase microtubules in positioning the phragmoplast through interactions with the division site protein TANGLED1 (TAN1). In Chapter 3, I demonstrate that TAN1 is also recruited independently of the preprophase band by the phragmoplast. Finally, in Chapter 4, I use bioinformatics and whole genome resequencing to identify new molecular players important to division plane orientation or cytokinesis in maize. Altogether these chapters provide new perspectives into the function of TAN1 in maize.