Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2019
Publication Date: 4/13/2019
Citation: Okubara, P.A., Peetz, A.B., Sharpe, R.M. 2019. Cereal root interactions with soilborne pathogens - from trait to gene and back. Agronomy. 9(4):188. https://doi.org/10.3390/agronomy9040188.
Interpretive Summary: In this review, we discuss how mapping of loci for disease resistance, done by breeders for crop improvement, could benefit from next-generation sequencing data, done by molecular biologists to discover novel resistance genes. Conversely, leads for novel resistance might arise by identifying the genes corresponding to mapped loci. The review focuses on the major soilborne fungal and nematode diseases of wheat, barley and rice as found in the Pacific Northwest, USA and throughout the world. Improvement of disease resistance will benefit from integration of molecular genetics and ‘omics approaches.
Technical Abstract: Realizing the yield potential of crop plants in the presence shifting pathogen populations, soil quality, rainfall and other agro-environmental variables remains a challenge for growers and breeders worldwide. In this review, we discuss current approaches for combatting the soilborne phytopathogenic nematodes Pratylenchus and Heterodera of wheat and barley, and Meloidogyne graminicola of rice. The necrotrophic fungal pathogens Rhizoctonia solani AG-8 and Fusarium spp. of wheat and barley also are discussed. These pathogens constitute major causes of yield loss in small-grain cereals of the Pacific Northwest, USA and throughout the world. Current topics include new sources of genetic resistance, molecular leads from whole genome sequencing and genome-wide patterns of host, nematode or fungal gene expression during root-pathogen interactions, host-induced gene silencing, and building a molecular toolbox of genes and regulatory sequences for deployment of resistance genes. In conclusion, improvement of wheat, barley and rice will require multiple approaches.