Chloroplast Cu/Zn-SOD is a highly sensitive site in cucumber leaves chilled in the light

Date

2002

Authors

Choi, Sun Mi
Jeong, Suk Weon
Jeong, Won
Kwon, Seung Ho
Chow, Wah S (Fred)
Park, Youn-Il

Journal Title

Journal ISSN

Volume Title

Publisher

Springer

Abstract

Light-chilling stress, the combination of low-light illumination and low temperature, preferentially inactivated photosystem I (PSI) of cucumber (Cucumis sativus L.) leaves, resulting in the photoinhibition of photosynthesis. The extent of PSI photoinhibition, determined in vivo by monitoring absorption changes around 810 nm (induced by far-red light), was closely correlated with the redox state of the PSII electron acceptor QA, measured as the chlorophyll fluorescence parameter, 1-qP, where qP is a photochemical quenching coefficient. In contrast, the decrease in the far-red-induced leaf absorptance signal was not well correlated with the limited fragmentation of the PsaA/B gene products in the PSI reaction center after the light-chilling stress. Amongst various enzymes involved in the photooxidative damage such as superoxide dismutase (SOD), ascorbate peroxidase, and NAD(P)H dehydrogenase, only SOD was inhibited by light-chilling treatment. Further, an approximately 3-fold increase in the leaf content of H2O2, a potent inhibitor of Cu/Zn-SOD, was observed after light-chilling stress. From these results, we suggest that Cu/Zn-SOD is the primary target of the light-chilling stress, followed by subsequent inactivation of PSI by reactive oxygen species.

Description

Keywords

Keywords: Chlorophyll; Enzymes; Light absorption; Lighting; Photosynthesis; Quenching; Photosystems; Plants (botany); Cucumis; Cucumis sativus; ascorbate peroxidase; chlorophyll; hydrogen peroxide; oxygen; peroxidase; reactive oxygen metabolite; reduced nicotinamid Cu/Zn-superoxide dismutase; Cucumis; Light-chilling; Photoinhibition; Photosystem I

Citation

Source

Planta

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1007/s00425-002-0852-z

Restricted until

2037-12-31