The International Congress on Photosynthesis Research is held every four years. Regional meetings in the Americas, Asia, and Europe are held at the two-year interval between congresses. The 18th International Congress was held in Dunedin, New Zealand, from July 31 to August 5, 2022. The Congress was originally planned for 2020 but postponed due to the COVID-19 pandemic. Due to border restrictions in New Zealand, the meeting was then planned as an on-line conference but a relaxing of border restrictions for travellers from some countries in March 2022 led to the meeting format converting to a fully hybrid structure with approximately 110 attendees in-person and a further 300 on-line from across the world. A satellite meeting on Rubisco was also held at the University of Canterbury in Christchurch, New Zealand, on July 30 and a second satellite on water oxidation was held on August 6–7 at the University of Otago in Dunedin.

The six contributions in this Special Issue have been provided by invited speakers at the Congress. A full list of plenary speakers is given in Appendix 1. The first is from Jindong Zhao and co-workers (Wang et al. 2023) reporting the unique characteristics of the phycobilisome from the cyanobacterium Gloeobacter violaceus, which lacks thylakoid membranes. The report also describes a novel system for creating targeted mutants in this organism. The remaining five contributions each provide a review of a specific topic establishing a current picture of many aspects of photosynthesis research. A detailed assessment of protein channels involved in substrate delivery and proton egress to and from the Mn4CaO5 oxygen-evolving complex of Photosystem II is presented by Junko Yano and co-workers (Hussein et al. 2023); these authors also compare the various channels in cyanobacteria, red and green algae, diatoms, and higher plants. Two reviews follow that are focussed on improving photosynthesis, particularly in the face of climate change. The first by Amanda Cavanagh and Donald Ort (Cavanagh and Ort 2023) looks at transgenic strategies to improve thermotolerance in plants highlighting the widespread impacts of heat stress on photosynthesis. Current proof of concept successes at mitigating these effects are described and outstanding challenges for ensuring food security are discussed. Future food security is also addressed by the contribution from Robert Furbank and Susanne von Caemmerer with their colleague Steven Kelly (Furbank et al. 2023). These authors provide a detailed update on the progress being made by the Bill and Melinda Gates funded project to establish C4 rice. The remaining two contributions consider plant adaptations to optimize photosynthetic performance. The review by Ülo Niinemets (Niinemets 2023) examines the interactions between structural, chemical, and physiological leaf characteristics that are required for optimization of photosynthetic capacity by plant canopies. How mosses survive in Antarctica is the topic of the review by Sharon Robinson and colleagues (Yin et al. 2023). The ability of mosses to take advantage of microclimates to protect themselves from excess light energy, including damaging UV-B exposure, is explored in this account of how these plants successfully perform photosynthesis in one of the most challenging environments on the planet.

In addition to the plenary presentations, keynote talks were given by four recipients of awards conferred by the International Society of Photosynthesis Research (ISPR) (Fig. 1). A full list of ISPR awards and awardees is given in Appendix 2. Martin Jonikas, the recipient of the Calvin-Benson award gave a presentation on the “Structure, biogenesis, and engineering of the pyrenoid”, noting that approximately one-third of global CO2 fixation occurs in this algal organelle. Michihiro Suga, the recipient of the Hill Award, gave a talk entitled “Structural studies of the oxygen-evolving complex by using x-ray free electron lasers”. The Calvin-Benson and Hill Awards are both sponsored by the journal Photosynthesis Research, published by Springer. The Jan Anderson Award lecture was given by Benjamin Engel. This award commemorates the contributions to photosynthesis research by Professor Jan Anderson FAA, FRS (1932–2015). It was fitting that Benjamin Engel’s talk was on “Inspirations from Jan Anderson: Lateral heterogeneity in the age of cryo-electron tomography”. Jan Anderson’s seminal contributions to our understanding of lateral heterogeneity in thylakoid membranes (Andersson and Anderson 1980) form the basis of much of this research. The recipient of the Jalal Aliyev Award Lecture Scholarship was Donald Ort. This award commemorates the contributions of Professor Jalal Aliyev (1932–2015) to photosynthesis (Huseynova et al. 2016). The lecture by Donald Ort was entitled “Mitigating the impact of a warming climate on photosynthetic carbon gain with an alternative photorespiratory pathway”. Both the Jan Anderson and Jalal Aliyev awards are supported by contributions from members of ISPR.

Fig. 1
figure 1

ISPR award speakers at the 18th International Congress on Photosynthesis Research. a Martin Jonikas, The Calvin-Bensen Award. b Michihiro Suga, The Hill Award. c Benjamin Engel, The Jan Anderson Award. d Donald Ort, The Jalal Aliyev Award

Full size image

Two additional awards were made at the Congress in Dunedin. The Lifetime Achievement Award, which confers life membership to ISPR, was jointly awarded to Eva-Mari Aro for her outstanding contribution to our current view of the molecular mechanisms underpinning photosynthetic acclimation and Govindjee Govindjee, awarded for his lifelong contribution to understand photosynthesis and in particular Photosystem II (Eaton-Rye 2019; Jajoo et al. 2023) (Fig. 2). In addition, the ISPR Innovation Award (sponsored by LI-COR Biosciences) was jointly awarded to Maureen Hanson and Martin Parry for their successful replacement of Rubisco in tobacco with the enzyme from Synechococcus elongatus (Fig. 3). Four conference poster awards, sponsored by Agrisera, were also given (Appendix 3 and Fig. 4).

Fig. 2
figure 2

The joint winners of the ISPR Lifetime Achievement Award. a Eva-Mari Aro. b Govindjee Govindjee

Full size image
Fig. 3
figure 3

The joint winners of the ISPR Innovation Prize. a Maureen Hanson. b Martin Parry

Full size image
Fig. 4
figure 4

Poster winners at the 18th International Congress on Photosynthesis Research. From left to right: Professor Wim Vermass (ISPR president 2017–2022) who presented the awards, Pierrick Bru, Soichiro Seki, Afshan Begum and Tanya Skinner

Full size image

Finally we would like to express our thanks to all the authors who have contributed to this Special Issue. In addition, we would like to thank the reviewers for their thoughtful comments and improvements. We also thank Johannes Messinger (Editor-in-Chief) and Matthew Hong Kei Cheng at Springer Nature for their assistance and guidance in the preparation of this volume of Photosynthesis Research.