title: Wood Formation in Trees Is Increased by Manipulating PXY-Regulated Cell Division.
abstract: The woody tissue of trees is composed of xylem cells that arise from divisions of stem cells within the cambial meristem. The rate of xylem cell formation is dependent upon the rate of cell division within the cambium and is controlled by both genetic and environmental factors. In the annual plant Arabidopsis, signaling between a peptide ligand CLE41 and a receptor kinase PXY controls cambial cell divisions; however, the pathway regulating secondary growth in trees has not been identified. Here, we show that an aspen receptor kinase PttPXY and its peptide ligand PttCLE41 are functional orthologs and act to control a multifunctional pathway that regulates both the rate of cambial cell division and woody tissue organization. Ectopic overexpression of PttPXY and PttCLE41 genes in hybrid aspen resulted in vascular tissue abnormalities and poor plant growth. In contrast, precise tissue-specific overexpression generated trees that exhibited a 2-fold increase in the rate of wood formation, were taller, and possessed larger leaves compared to the controls. Our results demonstrate that the PXY-CLE pathway has evolved to regulate secondary growth and manipulating this pathway can result in dramatically increased tree growth and productivity.
authors: Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK.
authors: J Peter
authors: JP
authors: Etchells
authors: Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK.
authors: Laxmi S
authors: LS
authors: Mishra
authors: Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK.
authors: Manoj
authors: M
authors: Kumar
authors: Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK.
authors: Liam
authors: L
authors: Campbell
authors: Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK. Electronic address: simon.turner@manchester.ac.uk.
authors: Simon R
authors: SR
authors: Turner
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002455:Cell Division / Q000235:genetics* / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000235:genetics / Q000378:metabolism*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D014197:Trees / Q000235:genetics / Q000254:growth & development*; D015854:Up-Regulation; D014934:Wood / Q000235:genetics / Q000254:growth & development*
chemical_list: D029681:Arabidopsis Proteins; C547646:CLE41 peptide, Arabidopsis; D009842:Oligopeptides; D011494:Protein Kinases; C524131:PXY protein, Arabidopsis