English Seminars
Auxin and Rho-of-plant direct actin-mediated polar nuclear migration in Arabidopsis root epidermal hair cells
| Title | Auxin and Rho-of-plant direct actin-mediated polar nuclear migration in Arabidopsis root epidermal hair cells |
| Lecturer | Dr. Moritaka Nakamura( Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam) |
| Language | English |
| Date&Time | 09/06/2016 (Tue) 16：00～09/16/2016 (Fri) 17：00 |
| Venue | Large Seminar Room |
| Detail | Polar nuclear movement at the subcellular level is crucial during multiple events in eukaryotic development. In most cases, components and regulators of the cytoskeleton as well as nuclear envelope proteins are major components involved, as demonstrated by severe developmental disorders in respective mutants. In the Arabidopsis root epidermis, the nucleus initially assumes a position at the inner lateral membrane during cell elongation and moves towards the root hair after hair bulging. Except for its actin-dependence demonstrated by pharmacological studies, little is known about dynamic hallmarks and regulatory mechanisms underlying this polar nuclear migration. Here, we report that nuclear auxin signaling and Rho-of-Plant (ROP) signaling direct actin-dependent polar nuclear migration towards the root hair bulge. Time-lapse imaging reveals that the nucleus located at the inner lateral membrane starts its actin-associated movement towards the outgrowing root hair in an ACTIN7 (ACT7)-dependent manner. Loss of ACT7 function as well as reduced or enhanced activation of ROP signaling alter polar nuclear migration. High auxin concentration or reduced CTR1 kinase function induce nuclear mis-positioning that is suppressed by ARF7 ARF19 loss of function, revealing that nuclear auxin signaling regulates nuclear migration. Our findings establish a mechanistic framework of auxin- and ROP-signaling-directed, ACT7-dependent polar nuclear migration in the Arabidopsis root epidermis. |
| Contact | 植物形態ダイナミクス 田坂 昌生 (m-tasaka@bs.naist.jp) |