“Temp-Resist Rice”: exploiting novel germplasm to deliver improved heat tolerance and future-proofed rice yields

Rice agriculture is the most extensive use of land for global food production, predominantly for direct human consumption. It impacts the global economy, not only in areas of primary production/consumption. The UK has a thriving rice research community interconnected to institutes in rice growing countries. UK research in fundamental discovery science has enabled complementarity and synergism, feeding into global partnerships and the increased use of rice as a UK model crop. Rice is the primary source of calories and nutrition for >3.5bn people (67% of total global cereal consumption; 23% of protein intake). Population growth predicts rice yield needs to increase by 50% before 2050; this challenge is compounded by environmental change, particularly temperature increases and water shortages. Estimates are that global rice yield declines by 7-8% per 1°C increase above optimum growth temperatures. Rice reproduction, especially pollen development, and photosynthesis, are particularly sensitive to heat stress. It is not known whether the failure of reproduction and therefore seed set and yield is because pollen development is particularly sensitive to heat, or whether it is a secondary consequence of disruption of energy generation by impaired photosynthesis under heat stress, or more likely a combination of both. However, addressing this fundamental question is important to enable effective systems for heat stress resilience to be identified and to understand how they function and thus generate materials that can withstand heat stress in an agricultural field environment. This programme will address this question alongside generating rice germplasm and markers to enable rapid trait deployment in breeding programmes. The work involves a partnership with the International Rice Research Institute (IRRI) in the Philippines, which will enable testing of rice germplasm under in-field conditions of heat stress, and utilisation of their rice populations that have been established to enable screening for heat resistance and thus generation of a pipeline for trait identification and deployment. It will also involve detailed analysis of several candidate genes that we have identified as promising for delivering resilience to heat stress. The outcomes of this work will be better understanding of the process of heat resilience and confirmation of traits that offer heat resistance in field scenarios. This will generate materials for breeding using elite germplasm which will be assessed at IRRI and form part of their future breeding programmes. The outcomes of this research will also be directly transferable to other cereals, particularly wheat and barley, which also have similar susceptibility to heat stress.