Net O2 exchange rates under dark and light conditions across different stem compartments

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Woody plants display some photosynthetic activity in stems, but the biological role of stem photosynthesis and the specific contributions of bark and wood to carbon uptake and oxygen evolution remain poorly understood.
We aimed to elucidate the functional characteristics of chloroplasts in stems of different ages in Fraxinus ornus. Our investigation employed diverse experimental approaches, including microsensor technology to assess oxygen production rates in whole stem, bark, and wood separately. Additionally, we utilized fluorescence lifetime imaging microscopy (FLIM) to characterize the relative abundance of photosystems I and II (PSI : PSII chlorophyll ratio) in bark and wood.
Our findings revealed light-induced increases in O2 production in whole stem, bark, and wood. We present the radial profile of O2 production in F. ornus stems, demonstrating the capability of stem chloroplasts to perform light-dependent electron transport. Younger stems exhibited higher light-induced O2 production and dark respiration rates than older ones.
While bark emerged as the primary contributor to net O2 production under light conditions, our data underscored that wood chloroplasts are also photosynthetically active. The FLIM analysis unveiled a lower PSI abundance in wood than in bark, suggesting stem chloroplasts are not only active but also acclimate to the spectral composition of light reaching inner compartments.
TidsskriftNew Phytologist
Udgave nummer1
Sider (fra-til)72-81
Antal sider10
StatusUdgivet - 2024

Bibliografisk note

Funding Information:
The authors acknowledge Euro\u2010BioImaging ( ) for providing access to imaging technologies and services via the Wageningen Imaging and Spectroscopy Hub (WISH) \u2013 ALM and Molecular Imaging Node Wageningen (Wageningen, the Netherlands) and funding via the Euro\u2010BioImaging Italian Fund grant. The funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska\u2010Curie grant agreement no. 801199 and EMBO Postdoctoral Fellowship no. ALTF 619\u20102022 (LLPO) is acknowledged. We are very grateful to the \u2018Direzione centrale risorse agroalimentari, forestali e ittiche \u2013 area foreste e territorio\u2019 of the \u2018Regione Autonoma Friuli Venezia Giulia\u2019, and to the public nursery Vivai Pascul (Tarcento, Italy) for providing the plant material for the FLIM experiment.

Publisher Copyright:
© 2024 The Authors. New Phytologist © 2024 New Phytologist Foundation.

ID: 391676365