b'a genome editing technique could be applied to the species inparticipating companies demonstrate the tremendous interest in question? Could the crop species be worked on in the breedingthe topic among plant breeding companies of all sizes. This can companies involved?be seen as a first result: Genome editing methods hold promise. The project was initiated for two reasons: First for demon-stration purposes, successful completion of the project in theMOLECULAR BASIS: DEACTIVATE NEGATIVE foreseeable future should not be per se impossible. Secondly toREGULATORS IN PATHOGEN DEFENCEgenerate genetic material for the breeders. For the same rea- The breeding work required for the project was carried out using sons, economic relevance of the crop and difficulty to achieve thetargeted mutagenesis with Cas endonucleases. In the process, same aim with conventional methods were important criteria,individual existing wheat genes have been edited in specific too. Project proposals that required long-term basic research orways. The molecular bases of the project relate to the natural any extensive precursory steps were deemed unsuitable. In thedefence responses of the wheat plant that are normally induced end, the evaluation process of all these individual componentsby a pathogen. Negative regulators will usually switch off these resulted in the wheat project named PILTON.pathogen defences sometime after its activation. As a result, this defence can only act for a very limited time in the event of AIMS OF THE JOINT RESEARCH PROJECT PILTON a pathogen attack and would therefore not prevent that the plant Wheat is the crop plant with the largest cultivation area inexhibits symptoms. Cas endonucleases were to be used to inac-Germany and Europe, and it is one of the essential staple cropstivate such a specific repressor gene in wheat. Once the negative in our global society. The PILTON project is also designed toregulator is removed, the natural, induced pathogen defence was demonstrate and quantify the potential to significantly reduceexpected to be much stronger and to remain active for a much the use of plant protection products. Furthermore, the projectlonger time. Such an enhanced defence reaction of the plant was should demonstrate how it is possible for plant breeding compa- assumed to be less targeted to individual pathogens and might nies to use genome editing methods, in the light of intellectuallead to a broad spectrum of tolerances. The project focuses on property implications.the diseases: wheat leaf rust, stripe rust, Septoria leaf spot and The project seeks to achieve a durable tolerance in wheatFusarium blight diseases.simultaneously against a variety of fungal diseases. The nec-essary breeding steps include targeted mutagenesis with CasWHAT HAS HAPPENED UNTIL NOWendonucleases. The genetic modifications are limited exclusivelyThe first step, namely the process of precisely editing the tar-to individual wheat genes already present in the wheat genome.geted genetic sequence, has been successfully completed, and If successful, this could showcase how the use of new breed- the modification has proven to be stable. This was a challenge, ing methods can directly benefit society, the economy, and theand in the process, the project partners gained a lot of insights. environment.The application of genome editing to the highly complex wheat PILTON was launched in 2020. The name is an acronym forgenome is not a given, but so far, the project has demonstrated the German full title and stands for "fungal tolerance of wheat bythat it can be done, i.e., the CRISPR/Cas method in question can means of new breeding methods". Fifty-five mostly medium-sizedbe successfully applied to the extremely complex plant genome plant breeding companies are involved in the project, which hasof wheat. been initiated by the German Federation for Plant InnovationIn a second step, the filial generations have been tested for (GFPi), a sister organisation of the German Plant Breeders\'resistance against various fungal pathogens. Tests were started Association (BDP) which is dedicated to research. BDP givesin 2021 and were partly repeated in 2022, but they are only pos-its communicative support to the project. The large number ofsible in the greenhouse which limits their comparability. Still, The first step, namely the process of precisely editing the targeted genetic sequence, has been successfully completed, and the modification has proven to be stable. Photo: Alexander Schlichter10IEUROPEAN SEEDIEUROPEAN-SEED.COM'