Miller Magazine Issue: 139 July 2021

30 MILLER / july 2021 NEWS Leading scientific experts are calling for governments around the world to come together and fund a new interna- tional research platform, to reduce the impact of major wheat pathogens and improve global food security. The John Innes Centre is calling for an internationally co- ordinated approach to deliver a new 'R-Gene Atlas', which would help identify new genetic solutions conferring disease resistance for crops, which could be bred into commercial wheat varieties. Globally, we lose one fifth of the projected wheat yield annually to pests and pathogens totaling losses of 209 million tonnes, worth $31 billion. The climate emer- gency has the capacity to bring further disruption to global food supplies, as a changing environment brings new types of pests and diseases and increases their spread. To mini- mise these losses, and to reduce reliance on chemical solu- tions, the team calls for broader use of disease resistance to be found in the genome of wheat and its wild relatives. The aim is to provide long-lasting molecular protection against wheat's major pathogens including wheat rusts, blotch dis- eases, powdery mildew, and wheat blast. Wheat R genes work by recognising corresponding mole- cules in the pathogen called effectors. By identifying the effec- tors present in pathogen and pest populations, more durable combinations or "stacks" of R genes could be designed. The R-gene atlas will be a free online portal containing this genet- ic information and enabling breeders to design gene stacks using computer modelling before starting their breeding in the field. It will enable users to design molecular markers that could be used to find out what resistance genes they already have in their breeding programme or wheat populations. The idea builds upon the recent surge in genomic resources avail- able to researchers in wheat, facilitated by advancements in sequencing technologies and bioinformatics. In the past few years, researchers at the John Innes Centre and The Sains- bury Laboratory have rapidly identified and cloned resistance genes in wheat and its wild relatives using technologies such as AgRenSeq, MutRenSeq and MutChromSeq. The new proposal details how the molecular components involved in disease resistance - R genes and effectors - could be captured from both the host and pathogen. Whole genome sequencing would be carried out on diversity panels of wheat, its progenitors and domesticated and wild relatives. Association genetics, a method of seeking useful genetic variation, could then be used to look for correlations between the host genotype and disease resistance or susceptibility and the genes responsible for these traits could be identified. The researchers calculate it would cost around $58.6 million to es- tablish the new platform at the required scale. Costed, detailed proposals for the R-Gene Atlas are set out in a new article in Molecular Plant. This would include sequencing diversity panels of the pathogens and 10 host species of wheat, as well as funding 75 scientists across the world to carry out the work. This, they suggest, could be funded by contributions of $2.9 million per G20 country spread over five years - a minor investment con- sidering the current financial losses across the world to wheat diseases. This extensively collaborative funding model would spread the risk on a project which would have global reward. Scientists call for international investment to tackle major wheat losses