The University of Western Australia and Professor Tim Colmer is, without comparison, my most important international collaborator. Our collaboration began in August 2005, and since then we have coauthored over 45 papers. I have visited UWA every year in October or November, sometimes more than once. UWA is highly attractive for its world-class growth facilities, including CERs, phytotrons, glasshouses, and a CT room. Together with Professor Colmer, I have access to extensive collections of rice and wheat cultivars, as well as their wild relatives.

Western Australia also offers a unique natural aquatic flora in its wetlands and the shallow waters of the Indian Ocean. I have been an adjunct at UWA since 2007. In 2018, 2019 and 2023, the Carlsberg Foundation funded research visits to UWA and Nagoya University, where we are continuing our work on the barrier to radial oxygen loss in rice.

The UWA glasshouse area, including CERs, phytotrons, and other glasshouse facilities. Dr. Dennis Konnerup is carrying a sample of rice roots for further analysis in the upstairs laboratories.

Professors Nakazono, Colmer, and Pedersen during a research visit to Nagoya University in June 2017. We were studying the barrier to radial oxygen loss in maize, teosinte (a wild maize relative), and an introgression line. Both teosinte and the introgression line form a barrier to radial oxygen loss when grown in waterlogged conditions.

The collaboration with Nagoya University in Japan began in 2014, when we initiated successful research with Professor Ashikari (Moto) and his team. This work led to the discovery of the LGF1 gene, which controls the superhydrophobic properties of the rice leaf cuticle during submergence, enabling the formation of leaf gas films.


In the past years, this collaboration has expanded to include Professor Nakazono and his group, who are studying aerenchyma formation and the barrier to radial oxygen loss in rice, maize (which does not form a barrier), a wild maize relative (teosinte), and some promising introgression lines that also form barriers. The ongoing research with Nagoya University has been supported by the Sasakawa Foundation, the Villum Foundation, and recently the Carlsberg Foundation.

The International Rice Research Institute (IRRI) in Los Baños, the Philippines has been an important partner in the past, and with the recent Danida grant for Climate-Smart African Rice, this collaboration will be further expanded. IRRI has an impressive collection of rice genotypes, including all wild rice species within the Oryza genus—an important resource for the work we do in my lab, making the IRRI partnership essential beyond the current Danida project. I have visited IRRI several times, with the 2011 visit being particularly productive. During that visit, we focused on complete submergence and the importance of leaf gas films for internal aeration in a field setting. We would not have been able to conduct such logistically demanding research without the help of IRRI staff, especially Dr. Ismail. 

I am also pleased that Dr. Ismail is now leading the African IRRI hub based in Nairobi, Kenya, since IRRI Africa in addition to Sokoine University of Agriculture in Tanzania is our main African partners on Climate-smart African rice.

Dr. Ismail is presenting the impressive field facilities during the ISPA Conference that was hosted by IRRI in 2013.

Dr Chen Lin was working with the late Prof Sauter at Kiel University where he  established an impressive culture of NIL12, which is used in our current collaboration.

A more recent but very important international collaboration was with Kiel University which is just 4 h drive from Copenhagen. Prof Margret Sauter who sadly passed away in January 2023, was head of Plant Developmental Biology and Physiology and was an internationally renowned scientist with a strong record in growth regulation of adventitious roots.

Prof Sauter and I have four publications with the most recent one is on aquatic adventitious roots formed by NIL12 which is based on T65 (a Taiwanese paddy rice) with a deepwater rice QTL inserted from chromosome 12. The phenotype produces large amounts of aquatic adventitious roots when the shoot is flooded and we have recently unravelled the oxygen supply during submergence to these roots.

After the passing of Prof Sauter, her PhD student, Dan Liu, came to my lab in Copenhagen, where she currently working with functional roles of aquatic adventitious roots using NIL12 as model plant.

In addition to the major collaborations with UWA and Nagoya University mentioned above, I also collaborate with Udine University (Professors Casolo and Zancani), Radboud University (Professors Visser and Roelof), and Florida Atlantic University (Professor Koch), where I am also an affiliated associate professor.