How and why do plant nuclei move in response to light?

• Published in: Plant signaling & behavior Vol. 3; no. 4; pp. 266 - 268
• Main Authors: Iwabuchi, Kosei, Takagi, Shingo
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01.04.2008; Landes Bioscience
• Subjects: Addendum; Binding; Biology; Bioscience; Calcium; Cancer; Cell; Cycle; Landes; Organogenesis; Proteins; actin; Arabidopsis; cytoskeleton; blue light; nucleus; nuclear positioning; phototropin
• ISSN: 1559-2316; 1559-2324; 1559-2324
• DOI: 10.4161/psb.3.4.5213

We recently found that nuclei take different intracellular positions depending upon dark and light conditions in Arabidopsis thaliana leaf cells. Under dark conditions, nuclei in both epidermal and mesophyll cells are distributed baso-centrally within the cell (dark position). Under light conditions, in contrast, nuclei are distributed along the anticlinal walls (light position). Nuclear re-positioning from the dark to light positions is induced specifically by blue light at >50 μmol m -2 s -1 in a reversible manner. Using analysis of mutant plants, it was demonstrated that the response is mediated by the blue-light photoreceptor phototropin2. Intriguingly, phototropin2 also seems to play an important role in the proper positioning of nuclei and chloroplasts under dark conditions. Light-dependent nuclear positioning is one of the organelle movements regulated by phototropin2. However, the mechanisms of organelle motility, physiological significance, and generality of the phenomenon are poorly understood. In this addendum, we discussed how and why nuclei move depending on light, together with future perspectives.