Rausenberger, JuliaTscheuschler, AnkeNordmeier, WiebkeWüst, FlorianTimmer, JensSchäfer, EberhardFleck, ChristianHiltbrunner, Andreas2024-05-032024-05-032011-09-020092-86741097-417210.1016/j.cell.2011.07.023https://irf.fhnw.ch/handle/11654/45739Phytochrome A (phyA) is the only photoreceptor in plants, initiating responses in far-red light and, as such, essential for survival in canopy shade. Although the absorption and the ratio of active versus total phyA are maximal in red light, far-red light is the most efficient trigger of phyA-dependent responses. Using a joint experimental-theoretical approach, we unravel the mechanism underlying this shift of the phyA action peak from red to far-red light and show that it relies on specific molecular interactions rather than on intrinsic changes to phyA's spectral properties. According to our model, the dissociation rate of the phyA-FHY1/FHL nuclear import complex is a principle determinant of the phyA action peak. The findings suggest how higher plants acquired the ability to sense far-red light from an ancestral photoreceptor tuned to respond to red light.en600 - Technik, Medizin, angewandte Wissenschaften01A - Beitrag in wissenschaftlicher Zeitschrift813-825