Stressed genomics - bringing relief to rice fields

Active research in rice genetics aided by full-genome sequence has generated results to address multiple problems caused by biotic and abiotic stresses. The main challenges are achieving stability of resistance against variable biological agents and defining the genetic basis of traits influenced strongly by genotype x environment interactions. As shown in bacterial blight disease, detailed knowledge of host-pathogen interactions has enabled a predictive strategy to combine specific genes to provide durable resistance. Large-effect QTLs conferring tolerance to submergence, salinity, and drought have been identified. Marker-aided incorporation of the submergence tolerance gene into popular rice varieties illustrates how gene discovery can be rapidly converted into useful products. Extensive use of parallel whole-genome expression and mapping analyses is expected to improve our understanding of QTL. To accelerate conversion of discoveries into products, much can be gained by using agronomically proven genotypes and by testing in multiple environments.