GrassRoots uses three main model systems, Arabidopsis (Arabidopsis thaliana), green millet (Setaria viridis) and Brachypodium (Brachypodium distachyon), to expedite trait and expression element discovery targeting economically important crops including corn, soybean, cotton and wheat. These high-value commercial crops possess large physical statures, long generation times and large complex genomes that are prohibitive to discovery efforts. In contrast, Arabidopsis, green millet and Brachypodium all possess a small and sequenced diploid genome, compact growth habit and fast generation time. These characteristics are amenable to comprehensive genomic analysis, high throughput phenotypic characterization, rapid propagation and genetic manipulations in screening and testing pipelines.

Arabidopsis (Arabidopsis thaliana) is a widely used model for plant research. It is a powerful genetic system with a wealth of resources supported by an active research community. Using Arabidopsis, GrassRoots has built a comprehensive platform for trait gene and expression element discovery and testing. Trait genes and expression elements discovered in this dicotyledonous plant have high translatability to dicot crops such as soybean and cotton.

Green millet (Setaria viridis) belongs to the Panicoid subfamily of grasses including a number of economically important crops such as corn, sorghum, sugarcane, millets and the emerging biofuel feedstock switchgrass. It has recently emerged as a model for C4 grasses. It is a particularly relevant model for corn yield trait gene discovery because it shares the same mode of C4 photosynthesis with corn and also would share similar metabolic advantages in nitrogen use and water use. It is an ideal model for expression element discovery targeting corn and other grass crops because of the high level of genome sequence conservation and collinearity. GrassRoots is developing an extensive set of genomic resources and screening tools in this model to target grass crop improvement.

Green millet (Setaria viridis)

photo by Evan T. Howel, Durham, NC

Brachypodium (Brachypodium distachyon) belongs to the Pooidiae subfamily of temperate grasses including major crops wheat and barley. It has also recently emerged as a leading model for energy crop improvement. GrassRoots is using Brachypodium for root trait optimization in grass crops.

Brachypodium (Brachypodium distachyon)