Review articlePolarity in plant asymmetric cell division: Division orientation and cell fate differentiation

- Intrinsic protein polarization mechanisms may commonly exist in both plant and animal cells.
- Polarization of plant cells is subject to the regulation of extrinsic cues.
- Asymmetric cell signaling and auxin function play roles in orientated cell division in plants.
- Polarized proteins and auxin signaling help to differentiate daughter cell fate in plants.

Asymmetric cell division (ACD) is universally required for the development of multicellular organisms. Unlike animal cells, plant cells have a rigid cellulosic extracellular matrix, the cell wall, which provides physical support and forms communication routes. This fundamental difference leads to some unique mechanisms in plants for generating asymmetries during cell division. However, plants also utilize intrinsically polarized proteins to regulate asymmetric signaling and cell division, a strategy similar to the differentiation mechanism found in animals. Current progress suggests that common regulatory modes, i.e. protein spontaneous clustering and cytoskeleton reorganization, underlie protein polarization in both animal and plant cells. Despite these commonalities, it is important to note that intrinsic mechanisms in plants are heavily influenced by extrinsic cues. To control physical asymmetry in cell division, although our understanding is fragmentary thus far, plants might have evolved novel polarization strategies to orientate cell division plane. Recent studies also suggest that the phytohormone auxin, one of the most pivotal small molecules in plant development, regulates ACD in plants.