Flavodiiron-mediated O<sub>2</sub> photoreduction at photosystem I acceptor-side provides photoprotection to conifer thylakoids in early spring.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37270605.
- Also identified by DOI 10.1038/s41467-023-38938-z and PMC identifier 10239515.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Green organisms evolve oxygen (O<sub>2</sub>) via photosynthesis and consume it by respiration. Generally, net O<sub>2</sub> consumption only becomes dominant when photosynthesis is suppressed at night. Here, we show that green thylakoid membranes of Scots pine (Pinus sylvestris L) and Norway spruce (Picea abies) needles display strong O<sub>2</sub> consumption even in the presence of light when extremely low temperatures coincide with high solar irradiation during early spring (ES). By employing different electron transport chain inhibitors, we show that this unusual light-induced O<sub>2</sub> consumption occurs around photosystem (PS) I and correlates with higher abundance of flavodiiron (Flv) A protein in ES thylakoids. With P700 absorption changes, we demonstrate that electron scavenging from the acceptor-side of PSI via O<sub>2</sub> photoreduction is a major alternative pathway in ES. This photoprotection mechanism in vascular plants indicates that conifers have developed an adaptative evolution trajectory for growing in harsh environments.
Medical subject headings
- Tracheophyta
- Pinus sylvestris