title: Characterization of MORE AXILLARY GROWTH genes in Populus.
abstract: BACKGROUND
  Strigolactones are a new class of plant hormones that play a key role in regulating shoot branching. Studies of branching mutants in Arabidopsis, pea, rice and petunia have identified several key genes involved in strigolactone biosynthesis or signaling pathway. In the model plant Arabidopsis, MORE AXILLARY GROWTH1 (MAX1), MAX2, MAX3 and MAX4 are four founding members of strigolactone pathway genes. However, little is known about the strigolactone pathway genes in the woody perennial plants.
  
  
  RESULTS
  Here we report the identification of MAX homologues in the woody model plant Populus trichocarpa. We identified the sequence homologues for each MAX protein in P. trichocarpa. Gene expression analysis revealed that Populus MAX paralogous genes are differentially expressed across various tissues and organs. Furthermore, we showed that Populus MAX genes could complement or partially complement the shoot branching phenotypes of the corresponding Arabidopsis max mutants.
  
  
  CONCLUSIONS
  This study provides genetic evidence that strigolactone pathway genes are likely conserved in the woody perennial plants and lays a foundation for further characterization of strigolactone pathway and its functions in the woody perennial plants.
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America.
authors.forename: Olaf
authors.initials: O
authors.lastname: Czarnecki
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America; National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America; Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, Northeast Normal University, Changchun, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, Northeast Normal University, Changchun, China.
authors.forename: Shucai
authors.initials: S
authors.lastname: Wang
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America.
authors.forename: Wellington
authors.initials: W
authors.lastname: Muchero
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America.
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Tuskan
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America.
authors.forename: Jin-Gui
authors.initials: JG
authors.lastname: Chen
mesh_terms: D018506:Gene Expression Regulation, Plant / Q000235:genetics; D007783:Lactones / Q000378:metabolism; D032306:Petunia / Q000235:genetics; D010641:Phenotype; D010937:Plant Growth Regulators / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics*; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D032107:Populus / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*
chemical_list: D007783:Lactones; D010937:Plant Growth Regulators; D010940:Plant Proteins