title: Characterization of early transcriptional responses to cadmium in the root and leaf of Cd-resistant Salix matsudana Koidz.
abstract: BACKGROUND
  Salix matsudana Koidz. is a fast growing tree species. It has a high cadmium (Cd) tolerance capacity, making it potentially suitable for phytoremediation. Presently, transcriptomic and physiological Cd response mechanisms are poorly understood. Transcriptomic analysis in early response to high (50 μM) Cd levels was investigated in leaf and root of Cd-resistant S. matsudana Koidz..
  
  
  RESULTS
  Analysis of the response profiles demonstrate the existence of a complex transcriptional network in the root and leaf when exposed to Cd. The main response in the root involved up-regulation of genes associated with defence response via callose deposition in the cell wall and cell wall thickening. In the leaf, transcripts related to biotic stress signalling and secondary metabolism were activated. Additionally, many lignin and brassinosteroids synthesis pathway genes were induced mainly in the leaf, indicating that gene response to Cd was tissue-specific. The Cd transcriptome results were consistent with observed physiological changes.
  
  
  CONCLUSIONS
  The sub-localization, transcriptional network, and physiological regulation demonstrate the tissue-specific manner of Cd response, and provide a novel insight into in early response of tree species to Cd exposure.
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. yifan85831647@sina.com.
authors.forename: Jingli
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. ml5774609397_l@163.com.
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.affiliation: Research Center on Life Sciences and Environmental Sciences, Harbin University of Commerce, Harbin, 150076, China. wei2013zheng@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. snowsun04006@hotmail.com.
authors.forename: Haizhen
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. ml5546129873@163.com.
authors.forename: Xudong
authors.initials: X
authors.lastname: Cao
authors.affiliation: School of Forestry, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. lxlikun@163.com.
authors.forename: Yunxiang
authors.initials: Y
authors.lastname: Lan
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. yangcp@nefu.edu.cn.
authors.forename: Chuanping
authors.initials: C
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China. chli0@163.com.
authors.forename: Chenghao
authors.initials: C
authors.lastname: Li
mesh_terms: D060406:Brassinosteroids / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D008031:Lignin / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects* / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects* / Q000378:metabolism*; D032108:Salix / Q000187:drug effects* / Q000235:genetics
chemical_list: D060406:Brassinosteroids; D004785:Environmental Pollutants; D002104:Cadmium; D008031:Lignin