Abstract
Plants exhibit various responses to illumination with blue light (BL), such as chloroplast movement and stomatal opening. We found that the nucleus in Arabidopsis thaliana mesophyll cells alters its intracellular position in response to BL.
In dark-adapted cells, the nucleus was positioned at the center of the bottom of the cells. After illumination with strong BL, the nucleus was positioned along the anticlinal wall. This response was induced by BL over 50 μmol m-2 s-1 but not under 10 μmol m-2 s-1. Red light exhibited little effect. To reveal photoreceptor involved in this response, phototropin mutants, phot1, phot2, and phot1phot2 were analyzed. The response was induced in phot1 but not in phot2 and phot1phot2, strongly suggesting that phot2 is involved in the BL-dependent nuclear positioning. To clarify cytoskeletal components involved in this response, inhibitor experiments are now in progress.
