Light Irradiation Induces Fragmentation of the Plasmodium, a Novel Photomorphogenesis in the True Slime Mold Physarum polycephalum: Action Spectra and Evidence for Involvement of the Phytochrome¶
- 1 January 2001
- journal article
- Published by Wiley in Photochemistry and Photobiology
- Vol. 73 (3), 324-329
- https://doi.org/10.1562/0031-8655(2001)073<0324:liifot>2.0.co;2
Abstract
A new photomorphogenesis was found in the plasmodium of the true slime mold Physarum polycephalum: the plasmodium broke temporarily into equal-sized spherical pieces, each containing about eight nuclei, about 5 h after irradiation with light. Action spectroscopic study showed that UVA, blue and far-red lights were effective, while red light inhibited the far-red-induced fragmentation. Difference absorption spectra of both the living plasmodium and the plasmodial homogenate after alternate irradiation with far-red and red light gave two extremes at 750 and 680 nm, which agreed with those for the induction and inhibition of the fragmentation, respectively. A kinetic model similar to that of phytochrome action explained quantitatively the fluence rate-response curves of the fragmentation. Our results indicate that one of the photoreceptors for the plasmodial fragmentation is a phytochrome.Keywords
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