caa a22 4500 606209476 CHVBK 20210128101028.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00425-014-2234-8 doi (NATIONALLICENCE)springer-10.1007/s00425-014-2234-8 The non-foliar hypoxic photosynthetic syndrome: evidence for enhanced pools and functionality of xanthophyll cycle components and active cyclic electron flow in fruit chlorenchyma [Elektronische Daten] [Alexandra Kyzeridou, Kostas Stamatakis, Yiola Petropoulou] Main conclusion : Green fruits display a high engagement in CEF and enhanced VAZ cycle activity as a response to the demands imposed by their internal aerial conditions, particularly low O 2 , due to gas exchange limitations. In the present study, we used HPLC analysis, post-illumination changes in fluorescence yield under varying O2 and CO2 partial pressures and absorbance changes at 820nm induced by far-red light to assess the carotenoid composition, the functionality of the xanthophyll cycle (VAZ) and the possibility of an active cyclic e − flow (CEF) in the fully exposed green fruits from Nerium oleander and Rosa sp. Equally exposed, mature leaves served as controls. Compared to leaves, fruits display less total chlorophylls and carotenoids but higher Car/Chl ratio, mainly shaped by the increased pools of the VAZ cycle components, in both species. The enhanced VAZ pool size in fruits is combined with a higher mid-day de-epoxidation state (DEPS). Moreover, fruits exhibit considerably lower levels of oxidizable P700, a faster re-reduction of PSI and significantly higher relative magnitude of CEF, irrespective of the O2/CO2 levels applied. We conclude that the higher VAZ investment may serve the enhanced heat dissipation needs in fruits, in the presence of a suppressed linear e − flow. In addition, the elevated potential of CEF may replenish the ATP lost due to hypoxia and concurrently facilitate the development of adequate non-photochemical quenching (NPQ), through its contribution to ΔpH increase. Since other non-foliar green organs exhibit a similar photosynthetic pattern, we argue that this may reflect a common strategy for green tissues under similar micro-environmental conditions, particularly hypoxia. Springer-Verlag Berlin Heidelberg, 2015 Fruit photosynthesis nationallicence Harmless dissipation nationallicence PSI absorbance nationallicence Hypoxia nationallicence Post-illumination fluorescence changes nationallicence Kyzeridou Alexandra Department of Biology, Laboratory of Plant Physiology, University of Patras, 265 04, Patras, Greece aut Stamatakis Kostas Institute of Biosciences and Applications, NCSR Demokritos, Agia Paraskevi Attikis, 153 10, Athens, Greece aut Petropoulou Yiola Department of Biology, Laboratory of Plant Physiology, University of Patras, 265 04, Patras, Greece aut Planta Springer Berlin Heidelberg 241/5(2015-05-01), 1051-1059 0032-0935 241:5<1051 2015 241 425 https://doi.org/10.1007/s00425-014-2234-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00425-014-2234-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kyzeridou Alexandra Department of Biology, Laboratory of Plant Physiology, University of Patras, 265 04, Patras, Greece aut NATIONALLICENCE 700 1- Stamatakis Kostas Institute of Biosciences and Applications, NCSR Demokritos, Agia Paraskevi Attikis, 153 10, Athens, Greece aut NATIONALLICENCE 700 1- Petropoulou Yiola Department of Biology, Laboratory of Plant Physiology, University of Patras, 265 04, Patras, Greece aut NATIONALLICENCE 773 0- Planta Springer Berlin Heidelberg 241/5(2015-05-01), 1051-1059 0032-0935 241:5<1051 2015 241 425