caa a22 4500 467894256 CHVBK 20180406152758.0 cr unu---uuuuu 170328e20060801xx s 000 0 eng 10.1007/s11103-006-0059-y doi (NATIONALLICENCE)springer-10.1007/s11103-006-0059-y The Populus homeobox gene ARBORKNOX1 reveals overlapping mechanisms regulating the shoot apical meristem and the vascular cambium [Elektronische Daten] [Andrew Groover, Shawn Mansfield, Stephen DiFazio, Gayle Dupper, Joseph Fontana, Ryan Millar, Yvonne Wang] Secondary growth is supported by a dividing population of meristematic cells within the vascular cambium whose daughter cells are recruited to differentiate within secondary phloem and xylem tissues. We cloned a Populus Class 1 KNOX homeobox gene, ARBORKNOX1 (ARK1), which is orthologous to Arabidopsis SHOOT MERISTEMLESS (STM). ARK1 is expressed in the shoot apical meristem (SAM) and the vascular cambium, and is down-regulated in the terminally differentiated cells of leaves and secondary vascular tissues that are derived from these meristems. Transformation of Populus with either ARK1 or STM over-expression constructs results in similar morphological phenotypes characterized by inhibition of the differentiation of leaves, internode elongation, and secondary vascular cell types in stems. Microarray analysis showed that 41% of genes up-regulated in the stems of ARK1 over-expressing plants encode proteins involved in extracellular matrix synthesis or modification, including proteins involved in cell identity and signaling, cell adhesion, or cell differentiation. These gene expression differences are reflected in alterations of cell wall biochemistry and lignin composition in ARK1 over-expressing plants. Our results suggest that ARK1 has a complex mode of action that may include regulating cell fates through modification of the extracellular matrix. Our findings support the hypothesis that the SAM and vascular cambium are regulated by overlapping genetic programs. Springer Science+Business Media B.V., 2006 Wood formation nationallicence Forestry nationallicence Stem cells nationallicence Extracellular matrix nationallicence Cell wall nationallicence Lignin nationallicence Groover Andrew Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut Mansfield Shawn Department of Wood Science, University of British Columbia, Vancouver, BC, Canada aut DiFazio Stephen Oakridge National Laboratory, Oak Ridge, TN, USA aut Dupper Gayle Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut Fontana Joseph Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut Millar Ryan Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut Wang Yvonne Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut Plant Molecular Biology Kluwer Academic Publishers 61/6(2006-08-01), 917-932 0167-4412 61:6<917 2006 61 11103 https://doi.org/10.1007/s11103-006-0059-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11103-006-0059-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Groover Andrew Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut NATIONALLICENCE 700 1- Mansfield Shawn Department of Wood Science, University of British Columbia, Vancouver, BC, Canada aut NATIONALLICENCE 700 1- DiFazio Stephen Oakridge National Laboratory, Oak Ridge, TN, USA aut NATIONALLICENCE 700 1- Dupper Gayle Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut NATIONALLICENCE 700 1- Fontana Joseph Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut NATIONALLICENCE 700 1- Millar Ryan Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut NATIONALLICENCE 700 1- Wang Yvonne Institute of Forest Genetics, Pacific Southwest Research Station, USDA Forest Service, 1100 West Chiles Rd., 95616, Davis, CA, USA aut NATIONALLICENCE 773 0- Plant Molecular Biology Kluwer Academic Publishers 61/6(2006-08-01), 917-932 0167-4412 61:6<917 2006 61 11103 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer