skip to main content


Title: BIG LEAF is a regulator of organ size and adventitious root formation in poplar

Here we report the discovery through activation tagging and subsequent characterization of the BIG LEAF (BL) gene from poplar. In poplar, BL regulates leaf size via positively affecting cell proliferation. Up and downregulation of the gene led to increased and decreased leaf size, respectively, and these phenotypes corresponded to increased and decreased cell numbers. BL function encompasses the early stages of leaf development as native BL expression was specific to the shoot apical meristem and leaf primordia and was absent from the later stages of leaf development and other organs. Consistently, BL downregulation reduced leaf size at the earliest stages of leaf development. Ectopic expression in mature leaves resulted in continued growth most probably via sustained cell proliferation and thus the increased leaf size. In contrast to the positive effect on leaf growth, ectopic BL expression in stems interfered with and significantly reduced stem thickening, suggesting that BL is a highly specific activator of growth. Additionally, stem cuttings from BL overexpressing plants developed roots, whereas the wild type was difficult to root, demonstrating that BL is a positive regulator of adventitious rooting. Large transcriptomic changes in plants that overexpressed BL indicated that BL may have a broad integrative role, encompassingmore » many genes linked to organ growth. Here, we conclude that BL plays a fundamental role in control of leaf size and thus may be a useful tool for modifying plant biomass productivity and adventitious rooting.« less
 [1] ;  [2] ;  [1] ;  [3] ;  [2] ;  [4] ;  [5]
  1. Michigan Technological Univ., Houghton, MI (United States). School of Forest Resources and Environmental Science; Eastern Illinois Univ., Charleston, IL (United States). Dept. of Biological Sciences
  2. Oregon State Univ., Corvallis, OR (United States). Dept. of Forest Ecosystems and Society
  3. Purdue Univ., West Lafayette, IN (United States). Dept. of Forestry and Natural Resources
  4. Michigan Technological Univ., Houghton, MI (United States). School of Forest Resources and Environmental Science
  5. Universidad Miguel Hernandez de Elche (Spain)
Publication Date:
Grant/Contract Number:
FG02-06ER64185; FG02-05ER64113; SC0008462
Accepted Manuscript
Journal Name:
Additional Journal Information:
Journal Volume: 12; Journal Issue: 7; Journal ID: ISSN 1932-6203
Public Library of Science
Research Org:
Virginia Polytechnic & State Univ., Blacksburg, VA (United States); Oregon State Univ., Corvalis, OR (United States); Michigan Technological Univ., Houghton, MI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
OSTI Identifier: