Abstract:
This study investigates the optical characteristics of bean leaves (Vicia faba L., cultivar “Russkie chernye”), which reflect the functional properties of the photosynthetic apparatus (PSA) in chloroplasts. The functioning of the PSA was assessed based on the kinetics of chlorophyll a fluorescence induction and light-induced changes in absorption, reflecting the redox transformations of photosystem 1 reaction centers (Ð$_{700}$). A comparison was made between the optical properties of leaves from control samples (plants grown under moderate light intensity, 2000–3000 lx) and etiolated leaves from plants cultivated under low light (5–10 lx). Using chlorophyll a fluorescence and changes in the Ð$_{700}$ state, we monitored the formation of the photosynthetic apparatus in chloroplasts during the illumination of etiolated leaves. It was shown that the development of active chloroplasts in etiolated leaves occurs within 2–3 days after exposure to intense light. An important feature of the diagnostic methods used in this study is their non-invasive nature, eliminating the need for chloroplast (or their component) isolation. Thus, instrumental analysis of leaf optical properties enables non-invasive monitoring of the plant PSA in situ at various stages of cultivation.
Keywords:plant photosynthetic apparatus, chlorophyll fluorescence, electron transport.
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