OAR@ICRISATComparative sequence analysis of nitrogen fixation-related genes in six legumesD HKimauthorSParupalliauthorSAzamauthorS HLeeauthorR KVarshneyauthorLegumes play an important role as food and forage crops in international agriculture especially in developing countries. Legumes have a unique biological process called nitrogen fixation (NF) by which they convert atmospheric nitrogen to ammonia. Although legume genomes have undergone polyploidization, duplication and divergence, NF-related genes, because of their essential functional role for legumes, might have remained conserved. To understand the relationship of divergence and evolutionary processes in legumes, this study analyzes orthologs and paralogs for selected 20 NF-related genes by using comparative genomic approaches in six legumes i.e., Medicago truncatula (Mt), Cicer arietinum, Lotus japonicus, Cajanus cajan (Cc), Phaseolus vulgaris (Pv), and Glycine max (Gm). Subsequently, sequence distances, numbers of synonymous substitutions per synonymous site (Ks) and non-synonymous substitutions per non-synonymous site (Ka) between orthologs and paralogs were calculated and compared across legumes. These analyses suggest the closest relationship between Gm and Cc and the highest distance between Mt and Pv in six legumes. Ks proportional plots clearly showed ancient genome duplication in all legumes, whole genome duplication event in Gm and also speciation pattern in different legumes. This study also reports some interesting observations e.g., no peak at Ks 0.4 in Gm-Gm, location of two independent genes next to each other in Mt and low Ks values for outparalogs for three genes as compared to other 12 genes. In summary, this study underlines the importance of NF-related genes and provides important insights in genome organization and evolutionary aspects of six legume species analyzed.ChickpeaPigeonpeaGroundnut2013http://www.frontiersin.orgArticle

For work being deposited by its own author: In self-archiving this collection of files and associated bibliographic metadata, I grant OAR@ICRISAT the right to store them and to make them permanently available publicly for free on-line. I declare that this material is my own intellectual property and I understand that OAR@ICRISAT does not assume any responsibility if there is any breach of copyright in distributing these files or metadata. (All authors are urged to prominently assert their copyright on the title page of their work.)

For work being deposited by someone other than its author: I hereby declare that the collection of files and associated bibliographic metadata that I am archiving at OAR@ICRISAT) is in the public domain. If this is not the case, I accept full responsibility for any breach of copyright that distributing these files or metadata may entail.

Clicking on the deposit button indicates your agreement to these terms.