title: Photosynthetic activity of vascular bundles in Plantago media leaves.
abstract: Photosynthetic processes in the leaf lamina and midribs of Plantago media were investigated using plants grown in high light (HL) or low light (LL) conditions. The fluorescence parameters, which indicate photochemical/photosynthetic activity, were different in HL and LL grown plants, but no major differences between lamina and midribs were found. An OJIP test (chlorophyll a fluorescence transient induction) of LL grown plants, indicative of the chloroplast electron transport chain, also showed both tissues to be similar. In HL plants, a partial blockage of electron flow between QA(the primary plastoquinone electron acceptor of PSII) and QB(the secondary plastoquinone acceptor of PSII) was found, and this was less visible in midribs. The effective dissipation of quantum energy per reaction center (DI0/RC) was similar in both tissues of HL grown plants, while in the midribs of LL leaves, this process seemed to be less effective. Measurements of13C discrimination showed that the midrib tissues of LL and HL leaves effectively used β-carboxylation products to accumulate their biomass. Thus, the well protected activity of electron transport in midribs with their limited capacity to fix CO2from the air may indicate the involvement of this tissue in β-carboxylation, transport or signaling. Carbon accumulated in roots showed a lower13C discrimination value (more negative) than the values observed in lamina. This could indicate that roots are supplied with assimilates mostly during the light phase of the day cycle with intensive C3photosynthesis.
authors: Małopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7a, 30-387 Kraków, Poland; The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland. Electronic address: zbigniew.miszalski@uj.edu.pl.
authors: Zbigniew
authors: Z
authors: Miszalski
authors: The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; Institute of Biology, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland.
authors: Andrzej
authors: A
authors: Skoczowski
authors: Institute of Biology, Komi Research Center, Ural Branch, Russian Academy of Sciences, Kommunisticheskaya 28, 167982 Syktyvkar, Russia.
authors: Ekaterina
authors: E
authors: Silina
authors: Institute of Biology, Komi Research Center, Ural Branch, Russian Academy of Sciences, Kommunisticheskaya 28, 167982 Syktyvkar, Russia.
authors: Olga
authors: O
authors: Dymova
authors: Institute of Biology, Komi Research Center, Ural Branch, Russian Academy of Sciences, Kommunisticheskaya 28, 167982 Syktyvkar, Russia.
authors: Tamara
authors: T
authors: Golovko
authors: Institute of Biology, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland. Electronic address: anko@up.krakow.pl.
authors: Andrzej
authors: A
authors: Kornas
authors: Department of Plant Physiology, Faculty and Biochemistry, Faculty of Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
authors: Kazimierz
authors: K
authors: Strzalka
mesh_terms: D002247:Carbon Isotopes; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D005453:Fluorescence; D006861:Hydrogen Peroxide / Q000378:metabolism; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000502:physiology*; D058526:Plant Vascular Bundle / Q000502:physiology*; D010943:Plantago / Q000502:physiology*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D045332:Photosystem II Protein Complex; D017392:Thiobarbituric Acid Reactive Substances; D002734:Chlorophyll; D002338:Carotenoids; C037184:chlorophyll b; D006861:Hydrogen Peroxide; D000077194:Chlorophyll A
keywords: Leaf lamina; Midrib; Photosynthetic/photochemical activity; Plantago