title: Functional repression of PtSND2 represses growth and development by disturbing auxin biosynthesis, transport and signaling in transgenic poplar.
abstract: Using chimeric repressor silencing technology, we previously reported that functional repression of PtSND2 severely arrested wood formation in transgenic poplar (Populus). Here, we provide further evidence that auxin biosynthesis, transport and signaling were disturbed in these transgenic plants, leading to pleiotropic defects in their growth patterns, including inhibited leaf enlargement and vascular tissue development in the leaf central vein, suppressed cambial growth and fiber elongation in the stem, and arrested growth in the root system. Two transgenic lines, which displayed the most remarkable phenotypic deviation from the wild-type, were selected for detailed studies. In both transgenic lines, expression of genes for auxin biosynthesis, transport and signaling was down-regulated, and indole-3-acetic acid distribution was severely disturbed in the apical buds, leaves, stems and roots of field-grown transgenic plants. Transient transcription dual-luciferase assays of ProPtTYDC2::LUC, ProPttLAX2::LUC and ProPoptrIAA20.2::LUC in poplar protoplasts revealed that expression of auxin-related genes might be regulated by PtSND2 at the transcriptional level. All these results indicate that functional repression of PtSND2 altered auxin biosynthesis, transport and signaling, and thereby disturbed the normal growth and development of transgenic plants.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Haihai
authors.initials: H
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China Present address: Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Renjie
authors.initials: R
authors.lastname: Tang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Cuiting
authors.initials: C
authors.lastname: Wang
authors.affiliation: College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P. R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Qi
authors.affiliation: College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P. R. China hxzhang@sippe.ac.cn gaiying@bjfu.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Gai
authors.affiliation: College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P. R. China The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of Chinese Forestry Administration, National Engineering Laboratory for Tree Breeding, Beijing 100083, P. R. China.
authors.forename: Xiangning
authors.initials: X
authors.lastname: Jiang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China hxzhang@sippe.ac.cn gaiying@bjfu.edu.cn.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Zhang
mesh_terms: D001692:Biological Transport / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000254:growth & development; D032107:Populus / Q000235:genetics* / Q000254:growth & development; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D014157:Transcription Factors; C030737:indoleacetic acid
keywords: PtSND2; chimeric repressor; indole-3-acetic acid; transgenic plant