Comparative genomics suggests that an ancestral polyploidy event leads to enhanced root nodule symbiosis in the Papilionoideae

Li, Q.-G., Zhang, L., Li, C., Dunwell, J. M. ORCID: https://orcid.org/0000-0003-2147-665X and Zhang, Y.-M. (2013) Comparative genomics suggests that an ancestral polyploidy event leads to enhanced root nodule symbiosis in the Papilionoideae. Molecular Biology and Evolution, 30 (12). pp. 2602-2611. ISSN 1537-1719 doi: 10.1093/molbev/mst152

Abstract/Summary

Root nodule symbiosis (RNS) is one of the most efficient biological systems for nitrogen fixation and it occurs in 90% of genera in the Papilionoideae, the largest subfamily of legumes. Most papilionoid species show evidence of a polyploidy event occurred approximately 58 million years ago. Although polyploidy is considered to be an important evolutionary force in plants, the role of this papilionoid polyploidy event, especially its association with RNS, is not understood. In this study, we explored this role using an integrated comparative genomic approach and conducted gene expression comparisons and gene ontology enrichment analyses. The results show the following: (1) approximately a quarter of the papilionoid-polyploidy-derived duplicate genes are retained; (2) there is a striking divergence in the level of expression of gene duplicate pairs derived from the polyploidy event; and (3) the retained duplicates are frequently involved in the processes crucial for RNS establishment, such as symbiotic signalling, nodule organogenesis, rhizobial infection and nutrient exchange and transport. Thus, we conclude that the papilionoid polyploidy event might have further refined RNS and induced a more robust and enhanced symbiotic system. This conclusion partly explains the widespread occurrence of the Papilionoideae.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/33777
Identification Number/DOI	10.1093/molbev/mst152
Refereed	Yes
Divisions	Life Sciences > School of Agriculture, Policy and Development > Department of Crop Science
Uncontrolled Keywords	legume; nitrogen fixation; papilionoid; polyploidy root nodule symbiosis
Publisher	Oxford University Press
Publisher Statement	The definitive publisher-authenticated version is available online at: http://mbe.oxfordjournals.org/content/30/12/2602
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