Investigating Nitrogen Fixation in the Medicago-sinorhizobium Symbiosis
The Medicago genus is of global importance to agriculture, with the perennial M. sativa being the most widely cultivated and studied member. After many years of studying this plant along with its microsymbiont Sinorhizobium meliloti, it became clear that another host was required to allow simultaneous study of the genetic determinants of both symbiotic partners.M. sativawas unsuited to this role as it is autotetraploid, allogamous and shows strong in-breeding depression, making the analysis of recessive mutations no easy task. Researchers identified the annual medic M. truncatulaas a viable alternative as this host is diploid, autogamous and possess a rapid generation time, among other traits. Consequently, this organism was chosen for sequencing.