title: A survey of Populus PIN-FORMED family genes reveals their diversified expression patterns.
abstract: The plant hormone auxin is a key regulator of plant development, and its uneven distribution maintained by polar intercellular auxin transport in plant tissues can trigger a wide range of developmental processes. Although the roles of PIN-FORMED (PIN) proteins in intercellular auxin flow have been extensively characterized in Arabidopsis, their roles in woody plants remain unclear. Here, a comprehensive analysis of PIN proteins in Populus is presented. Fifteen PINs are encoded in the genome of Populus, including four PIN1s, one PIN2, two PIN3s, three PIN5s, three PIN6s, and two PIN8s. Similar to Arabidopsis AtPIN proteins, PtPINs share conserved topology and transmembrane domains, and are either plasma membrane- or endoplasmic reticulum-localized. The more diversified expansion of the PIN family in Populus, comparing to that in Arabidopsis, indicates that some auxin-regulated developmental processes, such as secondary growth, may exhibit unique features in trees. More importantly, different sets of PtoPINs have been found to be strongly expressed in the roots, leaves, and cambium in Populus; the dynamic expression patterns of selected PtoPINs were further examined during the regeneration of shoots and roots. This genome-wide analysis of the Populus PIN family provides important cues for their potential roles in tree growth and development.
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Bobin
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China Key Laboratory of Non-wood Forest Product of State Forestry Administration, School of Forestry, Central South University of Forestry and Technology, Changsha 410004, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, Quebec, H3A 1B1, Canada.
authors.forename: Huanquan
authors.initials: H
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China chenjun@caf.ac.cn lumz@caf.ac.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing 210037, China Key Laboratory of Non-wood Forest Product of State Forestry Administration, School of Forestry, Central South University of Forestry and Technology, Changsha 410004, China chenjun@caf.ac.cn lumz@caf.ac.cn.
authors.forename: Mengzhu
authors.initials: M
authors.lastname: Lu
mesh_terms: D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D032107:Populus / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D021381:Protein Transport
chemical_list: D026901:Membrane Transport Proteins; D010940:Plant Proteins
keywords: Cambium; PIN family; Populus; endoplasmic reticulum; plasma membrane; shoot and root regeneration.