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Red-Light Transmittance Changes in Variegated Pelargonium zonale—Diurnal Variation in Chloroplast Movement and Photosystem II Efficiency

Authors :
Veljović Jovanović, Sonja
Kasalica, Bećko
Miletić, Katarina
Vidović, Marija
Šušić, Nikola
Jeremić, Dejan
Belča, Ivan
Veljović Jovanović, Sonja
Kasalica, Bećko
Miletić, Katarina
Vidović, Marija
Šušić, Nikola
Jeremić, Dejan
Belča, Ivan
Source :
International Journal of Molecular Sciences
Publication Year :
2023

Abstract

Chloroplast movement rapidly ameliorates the effects of suboptimal light intensity by accumulating along the periclinal cell walls, as well as the effects of excess light by shifting to the anticlinal cell walls. These acclimation responses are triggered by phototropins located at the plasma membrane and chloroplast envelope. Here, we used a recently developed non-invasive system sensitive to very small changes in red light leaf transmittance to perform long-term continuous measurements of dark–light transitions. As a model system, we used variegated Pelargonium zonale leaves containing green sectors (GS) with fully developed chloroplasts and achlorophyllous, white sectors (WS) with undifferentiated plastids, and higher phototropin expression levels. We observed biphasic changes in the red-light transmittance and oscillations triggered by medium intensities of white light, described by a transient peak preceded by a constant decrease in transmittance level. A slight change in red-light transmittance was recorded even in WS. Furthermore, the chloroplast position at lower light intensities affected the rapid light curves, while high light intensity decreased saturated electron transport, maximum quantum efficiency of photosystem II, and increased non-photochemical quenching of chlorophyll fluorescence and epidermal flavonoids. Our results extend the knowledge of light-dependent chloroplast movements and thus contribute to a better understanding of their role in regulating photosynthesis under fluctuating light conditions.

Details

Database :
OAIster
Journal :
International Journal of Molecular Sciences
Notes :
International Journal of Molecular Sciences
Publication Type :
Electronic Resource
Accession number :
edsoai.on1415738119
Document Type :
Electronic Resource