Why Sequence Foxtail Millet?

Maturing head of foxtail millet. Photo courtesy Andrew Doust, Univ. of Florida

Foxtail millet (Setaria italica) is a diploid grass with a relatively small genome (~515 Mb). It is an important grain crop in temperate, subtropical, and tropical Asia and in parts of southern Europe, and is grown for forage in North America, South America, Australia, and North Africa. The genetic map of foxtail millet is highly colinear with that of rice, despite the fact that these lineages last shared a common ancestor more than 50 million years ago. Hence, comparison of the rice and foxtail millet genomes will facilitate reconstruction of the ancestral grass genome. Most important, foxtail millet is a close relative of an important biofuel crop, switchgrass (Panicum virgatum). It is also closely related to pearl millet (Pennisetum glaucum), which is under investigation as a biofuel grain feedstock in regions unsuitable for maize cultivation, and napiergrass (Pennisetum purpureum), a grass with biofuel potential in hot/humid regions such as the southeastern United States. Switchgrass is a polyploid species with a large genome that will not be an easy target for full genome sequence analysis. However, switchgrass and foxtail millet are both temperate, C4 grass species (C3 and C4 represent different metabolic approaches to CO2 metabolism in plants), so foxtail millet should share many genetic and physiological processes with switchgrass. Hence, foxtail millet should serve as an excellent surrogate genome to assist future study and improvement of switchgrass and related biofuel crops.

Principal Investigators: J.L. Bennetzen, K.M. Devos, A.N. Doust, E.A. Kellogg, D. Ware, and J. Zale