Original scientific paper

Photosynthetic Electron Transport and Superoxide Dismutase Activity during Natural Senescence of Maple Leaves

Hrvoje Lepeduš orcid.org/0000-0001-9329-7007 ; Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
Ivana Štolfa ; Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
Sandra Radić ; Faculty of Science, University of Zagreb, Zagreb, Croatia
Mirna Ćurković Perica ; Faculty of Science, University of Zagreb, Zagreb, Croatia
Branka Pevalek-Kozlina ; Faculty of Science, University of Zagreb, Zagreb, Croatia
Vera Cesar ; Department of Biology, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia

Abstract

Natural senescence of maple (Acer pseudoplatanus L.) leaves was investigated. Three types of senescing leaves were used: green (G), yellow-green (YG) and yellow (Y) ones. Down regulation of photosynthetic performance was achieved due to significant degradation of total chlorophylls, decrease in maximum quantum yield of PSII (Fv/Fm) and relative electron transport rate (rel. ETR). Also, decrease in Rubisco LSU abundance as well as degradation of rbcL gene was shown in YG and Y leaves. Senescent leaves revealed significant increase in the capacity of PSII for oxygen evolution when expressed per chlorophyll unit. This was the most probable source of reactive oxygen species (ROS) excess. The level of SOD (superoxide dismutase) activity increased 3.5-fold in Y leaves in respect to G and YG leaves. The increase in ROS level as well as in SOD activity during natural senescence of maple leaves was associated with increased level of lipid peroxidation and protein carbonyl content.

Keywords

senescence; photosystem II; Rubisco LSU; SOD; lipid peroxidation; protein oxidation

Hrčak ID:

23397

URI

https://hrcak.srce.hr/23397

Publication date:

15.4.2008.

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