title: Loss of peripheral polypeptides in the stromal side of photosystem I by light-chilling in cucumber leaves.
abstract: Photosystem I (PSI) is severely damaged by chilling at 4 degrees C in low light, especially in the chilling sensitive plant cucumber. To investigate the early events in PSI photoinhibition, we examined structural changes in the level of pigment-protein complexes in cucumber leaves in comparison with pea leaves. The complexes were separated on a native green gel and an increase in the intensity of a band was observed only in light-chilled cucumber leaves. The 77 K fluorescence emission spectrum of this green band indicated that the band was mainly composed of PSI with light-harvesting complex I. Each lane was cut from the green gel and separated on a fully denaturing SDS-PAGE in the second dimension. The new green gel band observed after light-chilling in cucumber leaves lacked 19, 18, and 16.5 kDa polypeptides. These results suggest that light-chilling facilitates the release of three peripheral polypeptides as an early event of chilling stress in vivo, which results in the inactivation of PSI in intact cucumber leaves.
authors.affiliation: Department of Molecular Biology, Pusan National University, Busan 609-735, Korea.
authors.forename: Min-Hyuk
authors.initials: MH
authors.lastname: Oh
authors.forename: Rana B
authors.initials: RB
authors.lastname: Safarova
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Eu
authors.forename: Ismayil S
authors.initials: IS
authors.lastname: Zulfugarov
authors.forename: Jin-Hong
authors.initials: JH
authors.lastname: Kim
authors.forename: Hong Jin
authors.initials: HJ
authors.lastname: Hwang
authors.forename: Chin Bum
authors.initials: CB
authors.lastname: Lee
authors.forename: Choon-Hwan
authors.initials: CH
authors.lastname: Lee