Tree Genetics & Genomes

, Volume 8, Issue 1, pp 177–194

Evolution and divergence in the coding and promoter regions of the Populus gene family encoding xyloglucan endotransglycosylase/hydrolases

  • Xia Ye
  • Suhua Yuan
  • Hong Guo
  • Feng Chen
  • Gerald A. Tuskan
  • Zong-Ming Cheng
Original Paper

DOI: 10.1007/s11295-011-0431-1

Cite this article as:
Ye, X., Yuan, S., Guo, H. et al. Tree Genetics & Genomes (2012) 8: 177. doi:10.1007/s11295-011-0431-1


Xyloglucan endotransglycosylase/hydrolases (XTHs) are believed to modify the cell wall structure by cleaving a xyloglucan polymer and transferring the newly generated, potentially reducing, terminal to another xyloglucan. We report here the detailed analysis of 37 Populus trichocarpa XTH genes/proteins in their divergence in both the coding and 5′ promoter regions. Our results show that the Populus XTH genes have experienced whole-genome and local duplications and pre- and post-speciation divergence. Genome-wide and segmental duplications seem to be dominant in subfamily I and III, while tandem duplication seems to be the major mechanism for the subfamily II expansion, which also has higher average ratios of Ka/Ks compared to those in subfamily I and III. There was a general lack of organ-specific gene expression. In contrast, the expression patterns in subfamily II varied in response to various hormone treatments, with II-A being up-regulated and II-B down-regulated after 2 h of hormone treatment. Expression for this subfamily was verified using the 1.5-kb PtXTH22 promoter that was fused with the GUS reporter gene and transformed into Arabidopsis. The PtXTH22 promoter contains auxin response element, ethylene insensitive 3-like factors, and brassinosteroid response cis-elements. Histochemical GUS staining of transgenic Arabidopsis seedlings confirmed that the PtXTH22 promoter was up-regulated by several hormones.


Xyloglucan endotransglycosylase/hydrolases (XTHs)Gene duplications and divergenceGene expressionPopulusArabidopsis



Xyloglucan endotransglycosylase


Xyloglucan hydrolase


Xyloglucan endotransglycosylase/hydrolases




Indole-3-acetic acid


Salicylic acid


Gibberellic acid




Jasmonic acid


Abscisic acid



Supplementary material

11295_2011_431_MOESM1_ESM.doc (1.6 mb)
ESM 1The Ct data for each reaction of the XTH genes in Populus (DOC 1625 kb)
11295_2011_431_MOESM2_ESM.doc (42 kb)
ESM 2The efficiency for each pair primers of the XTH genes in Populus (DOC 41 kb)
11295_2011_431_MOESM3_ESM.doc (38 kb)
ESM 3The promoter sequences of paralogous genes (DOC 38 kb)
11295_2011_431_MOESM4_ESM.doc (52 kb)
ESM 4The gene models of the PtXTH genes (DOC 51 kb)
11295_2011_431_MOESM5_ESM.doc (48 kb)
ESM 5The gene structure analysis of the PtXTH genes (DOC 47 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Xia Ye
    • 1
    • 2
  • Suhua Yuan
    • 2
    • 5
  • Hong Guo
    • 3
  • Feng Chen
    • 2
    • 6
  • Gerald A. Tuskan
    • 4
    • 6
  • Zong-Ming Cheng
    • 2
    • 6
  1. 1.College of HorticultureHenan Agricultural UniversityZhengzhouPeople’s Republic of China
  2. 2.Department of Plant SciencesUniversity of TennesseeKnoxvilleUSA
  3. 3.Department of Biochemistry, Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleUSA
  4. 4.Environmental Science DivisionOak Ridge National LaboratoryOak RidgeUSA
  5. 5.Institute for Plant Genomics and BiotechnologyTexas A&M UniversityCollege StationUSA
  6. 6.Bioenergy Science CenterOak ridge National LaboratoryOak RidgeUSA