The legume genus Lupinus (commonly known as lupin) consists of around 280 species classified within the Genisteae tribe selleck catalog of the subfamily Faboideae with major centers of diversity in South and Western North America, the Andes, the Mediterranean regions, and Africa. This legume has been grown in rotations with cereals for at least 2000 years [1] and is widely distributed within the old and new worlds [2]. The grain may be easily harvested and contains the full range of essential amino acids, and because of its high concentration of sulfur containing amino acids has high feed value for stock [2]. The lupin root nodule bacteria have all been classified within the genus Bradyrhizobium [3,4] with the exception of Microvirga lupini that was found to nodulate with Lupinus texensis [5]. Bradyrhizobium spp.
are commonly associated with the nodulation of sub-tropical and tropical legumes such as soybean [6,7]. In contrast, lupins are the only agricultural grain legume nodulated by this genus in Mediterranean-type climatic zones. Strains of lupin-nodulating Bradyrhizobium are also able to nodulate the herbaceous Mediterranean legume Ornithopus (seradella) spp. In this context, lupin Bradyrhizobium strains are rare microsymbionts of herbaceous and crop legumes endemic to the cool climatic regions of the world. The cultivation of lupin in these regions provides a cash crop alternative to soy. Lupinus angustifolius in particular has been extensively used to extend grain production into poor quality soils without fertilizer supplementation since fixed nitrogen can be obtained from the symbiosis with Bradyrhizobium [8].
Considerable variation exists in the amount of N2 fixed in the lupin-Bradyrhizobium association [8]. This is significant in agricultural ecosystems, as the benefits derived from growing lupins accrue both to the grain produced and the N2 fixed [9]. A well-grown lupin crop may fix up to 300 kg of N per ha. It is therefore important to understand the genetic constraints to optimal N2 fixation in this symbiosis. Bradyrhizobium sp. strain WSM1417 represents the lower end of the scale in strain N2 fixation capacity on L. angustifolius, and hence its genome sequence presents an opportunity to understand the genetic elements responsible for this trait. Here we present a summary classification and a set of general features for Bradyrhizobium sp.
WSM1417 together with the description of the complete genome sequence and its annotation. Classification and general features Bradyrhizobium sp. WSM1417 is a motile, Gram-negative, non-spore-forming rod (Figure 1 Left and Center) Brefeldin_A in the order Rhizobiales of the class Alphaproteobacteria. It is slow growing in laboratory culture, forming 1-2mm colonies within 7-10 days when grown on half Lupin Agar (?LA) [10] at 28��C. Colonies on ?LA are white-opaque, slightly domed, moderately mucoid with smooth margins (Figure 1C).