TY - JOUR
T1 - Selaginella moellendorffii has a reduced and highly conserved expansin superfamily with genes more closely related to angiosperms than to bryophytes
AU - Carey, Robert E.
AU - Hepler, Nathan K.
AU - Cosgrove, Daniel J.
N1 - Funding Information:
The authors acknowledge the contributions of P. Kerr Wall and Claude W. dePamphilis for invaluable advice on the archive searches and phylogenetic analyses presented here. REC was supported by NSF grant IBN-9874432 to DJC for the initial genomic analysis and by an LVC Arnold Experiential Grant to REC and NKH for refined genomic and phylogenetic analysis. Computational analysis was supported by DOE Office of Science grant DE-FG02-84ER13179.
PY - 2013/1/3
Y1 - 2013/1/3
N2 - Background: Expansins are plant cell wall loosening proteins encoded by a large superfamily of genes, consisting of four families named EXPA, EXPB, EXLA, and EXLB. The evolution of the expansin superfamily is well understood in angiosperms, thanks to synteny-based evolutionary studies of the gene superfamily in Arabidopsis, rice, and Populus. Analysis of the expansin superfamily in the moss Physcomitrella patens revealed a superfamily without EXLA or EXLB genes that has evolved considerably and independently of angiosperm expansins. The sequencing of the Selaginella moellendorffii genome has allowed us to extend these analyses into an early diverging vascular plant.Results: The expansin superfamily in Selaginella moellendorffii has now been assembled from genomic scaffolds. A smaller (and less diverse) superfamily is revealed, consistent with studies of other gene families in Selaginella. Selaginella has an expansin superfamily, which, like Physcomitrella, lacks EXLA or EXLB genes, but does contain two EXPA genes that are related to a particular Arabidopsis-rice clade involved in root hair development.Conclusions: From sequence-based phylogenetic analysis, most Selaginella expansins lie outside the Arabidopsis-rice clades, leading us to estimate the minimum number of expansins present in the last common ancestor of Selaginella and angiosperms at 2 EXPA genes and 1 EXPB gene. These results confirm Selaginella as an important intermediary between bryophytes and angiosperms.
AB - Background: Expansins are plant cell wall loosening proteins encoded by a large superfamily of genes, consisting of four families named EXPA, EXPB, EXLA, and EXLB. The evolution of the expansin superfamily is well understood in angiosperms, thanks to synteny-based evolutionary studies of the gene superfamily in Arabidopsis, rice, and Populus. Analysis of the expansin superfamily in the moss Physcomitrella patens revealed a superfamily without EXLA or EXLB genes that has evolved considerably and independently of angiosperm expansins. The sequencing of the Selaginella moellendorffii genome has allowed us to extend these analyses into an early diverging vascular plant.Results: The expansin superfamily in Selaginella moellendorffii has now been assembled from genomic scaffolds. A smaller (and less diverse) superfamily is revealed, consistent with studies of other gene families in Selaginella. Selaginella has an expansin superfamily, which, like Physcomitrella, lacks EXLA or EXLB genes, but does contain two EXPA genes that are related to a particular Arabidopsis-rice clade involved in root hair development.Conclusions: From sequence-based phylogenetic analysis, most Selaginella expansins lie outside the Arabidopsis-rice clades, leading us to estimate the minimum number of expansins present in the last common ancestor of Selaginella and angiosperms at 2 EXPA genes and 1 EXPB gene. These results confirm Selaginella as an important intermediary between bryophytes and angiosperms.
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U2 - 10.1186/1471-2229-13-4
DO - 10.1186/1471-2229-13-4
M3 - Article
C2 - 23286898
AN - SCOPUS:84871715813
SN - 1471-2229
VL - 13
JO - BMC plant biology
JF - BMC plant biology
IS - 1
M1 - 4
ER -