Genome-Enabled Insights into Legume Biology - University of ...

sequencing and resequencing of legume species
will make this possible, but inevitably, it is
the research community’s capacity to develop
imaginative strategies for exploiting massive
sequence data that will move legume genomics
from the computer to biology.
SUMMARY POINTS
Annu. Rev. Plant Biol. 2012.63:283-305. Downloaded from www.annualreviews.org
by University of Minnesota - Twin Cities - Wilson Library on 05/07/12. For personal use only.
1. The genome sequences of three legumes—Glycine max, Medicago truncatula, andLotus
japonicus—have recently been completed, and they illustrate a history of whole-genome
duplication with important implications in legume biology. Glycine, in particular, underwent
a genome duplication event within the past 13 million years that is strikingly
evident in its genome architecture.
2. Most agriculturally important legume crops, including so-called orphan species, are phylogenetically
close to Glycine, Medicago,andLotus. Consequently, translational genomics
to orphaned legumes should be straightforward and practically useful. It also means
that major clades of more distant legumes remain largely unexplored from a genomic
perspective.
3. Analysis of legume genome sequence reveals hundreds of family-specific genes not observed
in other angiosperms. They include a large group of defensin-like peptide genes
seen only in Medicago and its close relatives that are exclusively expressed in nodules and
in some cases play important roles in rhizobial differentiation.
4. The aftermath of genome duplication in legumes involves extensive gene fractionation,
especially in the lineage leading to Medicago and Lotus, as well as apparent examples of
sub- and neofunctionalization. In some cases, products of whole-genome duplication
have contributed to the elaboration of a preexisting capacity for rhizobial nodulation.
DISCLOSURE STATEMENT
N.D.Y. is principal investigator of a National Science Foundation Plant Genome Research Program
grant that supported the sequencing of M. truncatula and later the development of an
M. truncatula HapMap platform.
ACKNOWLEDGMENTS
We thank Doug Cook, Rene Geurts, and R. Op den Camp for helpful discussions relating to
unpublished work; Robert Stupar for his review of the manuscript; and Sebastian Proost and Yves
Van der Peer for preliminary analyses involving the PLAZA platform.
LITERATURE CITED
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