The Medicago truncatula genome: a powerful resource for identifying novel resistance factors against legume powdery mildews

Powdery mildew is a serious fungal disease that significantly reduces the productivity of grain and forage legumes worldwide. Due to the harmful effects of fungicides and the high risk of generating fungicide-resistant fungal strains, the use of genetic means to develop resistant legume cultivars has emerged as the preferred strategy for powdery mildew disease management. Genetic characterization of crop legumes has been challenging because of their large and complex genomes. In this context, Medicago truncatula (barrel medic) has emerged as a powerful model to study legume biology because of its relatively small diploid genome, short generation time, and genetically diverse germplasm. Furthermore, the availability of genome assemblies of M. truncatula genotypes spanning a broad range of powdery mildew resistance phenotypes has made this legume an excellent system for deciphering resistance mechanisms as well as a reservoir for the identification of novel resistance loci. In this book chapter, we summarize our current knowledge of the genetic and molecular basis of powdery mildew resistance in M. truncatula and review the genomic and genetic tools that are available for the identification of new resistance genes that could potentially be used to develop legume cultivars with enhanced powdery mildew resistance.

Gupta M., Gupta A., Chandran D. (2022) Medicago truncatula as a model to decipher powdery mildew resistance in legumes. In: Sinharoy S., Kang Y., Benedito V. (eds) The Medicago truncatula Genome. Compendium of Plant Genomes. Springer, Cham. https://doi.org/10.1007/978-3-030-90757-0_5