caa a22 4500 445841788 CHVBK 20180317145346.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s10725-011-9616-8 doi (NATIONALLICENCE)springer-10.1007/s10725-011-9616-8 Local induction of senescence by darkness in Cucurbita pepo (zucchini) cotyledons or the primary leaf induces opposite effects in the adjacent illuminated organ [Elektronische Daten] [Kalina Ananieva, Evguéni Ananiev, Snejana Doncheva, Detelin Stefanov, Kiril Mishev, Miroslav Kamínek, Vaclav Motyka, Petre Dobrev, Jiři Malbeck] Local darkening of zucchini cotyledons or the primary leaf affected in an organ-specific manner the adjacent ones which remained under the initial light regime. Individual darkening of either the pair of cotyledons or the primary leaf led to acceleration of senescence expressed by lowering of chlorophyll content and net photosynthetic rate. Darkening of the pair of cotyledons induced a reduction in total cytokinin (CK) levels and increased CK oxidase/dehydrogenase (CKX) activity in the adjacent illuminated primary leaf. In addition, abscisic acid (ABA) content was increased which correlated with reduced stomatal aperture leading to decreased stomatal conductance and transpiration rate. In contrast, darkening of the adjacent primary leaf led to increased metabolic activity in the illuminated cotyledons including increased total CK levels in parallel with decreased CKX activity, decreased ABA content in correlation with increased stomatal aperture, stomatal conductance and transpiration rate. On the other hand, the functional activity of the photosynthetic apparatus as well as the transcript levels of the three photosynthesis-related genes psbA, psaB and rbcL remained almost unaffected in both illuminated organs. Thus, compared with the primary leaves, cotyledons appeared to be much more resistant to the dark stress applied either directly or to the adjacent primary leaf. Our results indicated the involvement of CKs and ABA signalling in the control of the communication mechanisms between cotyledons and the primary leaf that could operate in response to changing environmental factors like shading during earlier stages of plant development. Springer Science+Business Media B.V., 2011 Abscisic acid nationallicence Cotyledons nationallicence Cytokinins nationallicence Cytokinin oxidase/dehydrogenase nationallicence Dark treatment nationallicence Primary leaves nationallicence ABA : Abscisic acid nationallicence CK : Cytokinin nationallicence cis Z : cis-Zeatin nationallicence cis ZR : cis-Zeatin riboside nationallicence CKX : Cytokinin oxidase/dehydrogenase nationallicence DHZ : Dihydrozeatin nationallicence DHZR : Dihydrozeatin 9-riboside nationallicence DHZ7G : Dihydrozeatin 7-glucoside nationallicence DHZ9G : Dihydrozeatin 9-glucoside nationallicence DHZROG : Dihydrozeatin 9-riboside O-glucoside nationallicence DHZRMP : Dihydrozeatin 9-riboside-5′-monophosphate nationallicence IAA : Indole-3-acetic acid nationallicence iP : N6-(2-isopentenyl)adenine nationallicence iPR : N6-(2-isopentenyl)adenine 9-riboside nationallicence iP7G : N6-(2-isopentenyl)adenine 7-glucoside nationallicence iP9G : N6-(2-isopentenyl)adenine 9-glucoside nationallicence iPRMP : N6-(2-isopentenyl)adenine 9-riboside-5′-monophosphate nationallicence PSII : Photosystem II nationallicence psaB : A gene coding for PSI apoprotein PsaB nationallicence psbA : A gene coding for D1 protein of PSII reaction center nationallicence rbcL : A gene coding for the large subunit of Rubisco nationallicence Rubisco : Ribulose-1,5-bisphosphate carboxylase/oxygenase nationallicence SAGs : Senescence-associated genes nationallicence Z : trans-Zeatin nationallicence ZR : trans-Zeatin 9-riboside nationallicence Z7G : trans-Zeatin 7-glucoside nationallicence Z9G : trans-Zeatin 9-glucoside nationallicence ZOG : trans-Zeatin O-glucoside nationallicence ZROG : trans-Zeatin 9-riboside O-glucoside nationallicence ZRMP : trans-Zeatin 9-riboside-5′-monophosphate (abbreviations for cytokinins according to Kamínek et al. 2000) nationallicence Ananieva Kalina Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut Ananiev Evguéni Department of Plant Physiology, Faculty of Biology, St. Kliment Ohridsky University of Sofia, 8 Dragan Tsankov blvd., 1164, Sofia, Bulgaria aut Doncheva Snejana Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut Stefanov Detelin Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut Mishev Kiril Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut Kamínek Miroslav Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut Motyka Vaclav Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut Dobrev Petre Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut Malbeck Jiři Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut Plant Growth Regulation Springer Netherlands 65/3(2011-12-01), 459-471 0167-6903 65:3<459 2011 65 10725 https://doi.org/10.1007/s10725-011-9616-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10725-011-9616-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ananieva Kalina Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut NATIONALLICENCE 700 1- Ananiev Evguéni Department of Plant Physiology, Faculty of Biology, St. Kliment Ohridsky University of Sofia, 8 Dragan Tsankov blvd., 1164, Sofia, Bulgaria aut NATIONALLICENCE 700 1- Doncheva Snejana Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut NATIONALLICENCE 700 1- Stefanov Detelin Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut NATIONALLICENCE 700 1- Mishev Kiril Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113, Sofia, Bulgaria aut NATIONALLICENCE 700 1- Kamínek Miroslav Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut NATIONALLICENCE 700 1- Motyka Vaclav Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut NATIONALLICENCE 700 1- Dobrev Petre Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut NATIONALLICENCE 700 1- Malbeck Jiři Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 263, 165 02, Prague 6, Czech Republic aut NATIONALLICENCE 773 0- Plant Growth Regulation Springer Netherlands 65/3(2011-12-01), 459-471 0167-6903 65:3<459 2011 65 10725 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer