Phototransformation of the Far-red Light-absorbing Form of Large Pea Phytochrome by Laser Flash Excitation

概要

論文の詳細を見る
Phototransformation of the far-red light absorbing form (P_<FR>) of large pea phytochrome to the red-light absorbing form (P_R) was examined at 2℃ after a 715 nm laser flash excitation using a custom-built multichannel transient spectra analyzer. The maximum amount of phototransformation intermediates was produced by a pulse of about 50 mJ, which resulted in ca. 65% of P_R obtained at the photostationary equilibrium. Some flash-induced intermediates were assumed to return to P_<FR> m the dark. A difference spectrum measured at 10 μsec after the flash showed an absorbance increase at 651 nm and a decrease at 724 nm. When the sample was left in darkness after the flash light irradiation, absorbance in the red and far-red region gradually increased, but that in the green region rapidly decreased. The decay curve of intermediates measured at 554 nm could be resolved into three reaction components having rate constants of 2,500, 590 and 48 sec^<-1> respectively. Difference spectra also indicated that a small but significant increase in absorbance between 370 and 380 nm and a decrease around 415 nm took place 10-310 μsec after a flash.
日本植物生理学会の論文