Project abstract for group samac

Genomics of Alfalfa and Wild Rice and Their Pathogens

Controlling diseases in crop plants is critical for increasing yields and reducing potential negative effects of crop chemicals on the environment. Alfalfa (Medicago sativa) is the fourth most widely grown crop in the US. It is a highly nutritious feed for livestock and has many attributes that make it very attractive as a biofuel feedstock. Although most of the major root and vascular diseases of alfalfa are well controlled by stacking resistance genes, cultivars with resistance to multiple foliar diseases are not available. The long-term goal of this project is to identify genes that provide protection to alfalfa against multiple foliar diseases.

In previous work, accessions of the model legume Medicago truncatula, a close relative of alfalfa, were identified that are resistant to several foliar pathogens and microarray technology was used to identify genes specifically expressed in the resistance response. To better understand the function of several of these genes, the researchers produced transgenic alfalfa plants expressing interfering RNA (RNAi) constructs to down-regulate their expression and found plants became highly susceptible to several pathogens. They are using RNAseq to determine how these genes are affecting the defense response and possibly other metabolic functions. They are also identifying defense responses in wild rice using RNAseq. Ongoing projects are to sequence the genomes of Clavibacter michiganensis, a bacterial pathogen of alfalfa, and Cochliobolus miyabeanus, a fungal pathogen of wild rice. 

A bibliography of this group’s publications acknowledging MSI is attached.