Safeguarding wheat yields from cereal fungal invaders

Every year fungal pathogens destroy 10–23% of all major calorie and commodity crops. Traditionally, to limit fungal disease outbreaks resistance genes have been introgressed into crops, which is a slow process, and the resistance conferred is frequently overcome through emergence of new pathogen races. An increasingly attractive alternative is to identify and disrupt disease susceptibility genes (S-genes) that are targeted by plant pathogens to promote their growth and infection. Thus, S-gene disruption often confers broad, durable, non-race specific resistance that is very difficult for pathogens to overcome. We recently identified the wheat isocitrate lyase gene (TaICL) as a potential S-gene that when disrupted prevented infection by the wheat yellow rust pathogen (Puccinia striiformis f.sp. tritici, Pst). TaICL disruption led to elevation in glyoxylate cycle intermediates, and we found these compounds can also act to inhibit Pst infection.

The aim of this project is to: (i) evaluate how TaICL disruption leads to reduction in Pst infection progression, (ii) establish whether other genes in the glyoxylate cycle could be manipulated as additional sources of wheat rust resistance, and (iv) determine the breadth and suitability of TaICL-B disruption as a new source of resistance against the wheat rusts and beyond. This project provides a unique opportunity to generate fundamental knowledge with potential for immediate practical application in resistance breeding. While the student will be embedded in the Saunders Lab at the John Innes Centre, which is a multidisciplinary research lab, providing the opportunity to develop extensive skills in a breadth of areas, including plant pathology, molecular biology, cell biology and basic computational biology.

References

Ibe, C. N., et al. & Saunders, D. G. O. (2024) Isocitrate lyase promotes Puccinia striiformis f. sp. tritici susceptibility in wheat (Triticum aestivum) by suppressing accumulation of glyoxylate cycle intermediates. Plant J. [https://doi.org:10.1111/tpj.16908]

Corredor-Moreno P., et al. & Saunders D.G.O. (2021) The branched-chain amino acid aminotransferase TaBCAT1 modulates amino acid metabolism and positively regulates wheat rust susceptibility. The Plant Cell, 5: 1728-1747. [https://doi.org/10.1093/plcell/koab049]