title: The Arabidopsis thaliana NGATHA transcription factors negatively regulate cell proliferation of lateral organs.
abstract: The cell proliferation process of aerial lateral organs, such as leaves and flowers, is coordinated by complex genetic networks that, in general, converge on the cell cycle. The Arabidopsis thaliana NGATHA (AtNGA) family comprises four members that belong to the B3-type transcription factor superfamily, and has been suggested to be involved in growth and development of aerial lateral organs, although its role in the cell proliferation and expansion processes remains to be resolved in more detail. In order to clarify the role of AtNGAs in lateral organ growth, we took a systematic approach using both the loss- and gain-of-functional mutants of all four members. Our results showed that overexpressors of AtNGA1 to AtNGA4 developed small, narrow lateral organs, whereas the nga1 nga2 nga3 nga4 quadruple mutant produced large, wide lateral organs. We found that cell numbers of the lateral organs were significantly affected: a decrease in overexpressors and, inversely, an increase in the quadruple mutant. Kinematic analyses on leaf growth revealed that, compared with the wild type, the overexpressors displayed a lower activity of cell proliferation and yet the mutant a higher activity. Changes in expression of cell cycle-regulating genes were well in accordance with the cell proliferation activities, establishing that the AtNGA transcription factors act as bona fide negative regulators of the cell proliferation of aerial lateral organs.
authors.affiliation: Department of Biology, Kyungpook National University, Daegu, 702-701, Korea.|Department of Molecular Genetics and Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Byung Ha
authors.initials: BH
authors.lastname: Lee
authors.affiliation: Department of Biology, Kyungpook National University, Daegu, 702-701, Korea.|Korea Evaluation Institute of Industrial Technology, Daegu, 701-300, Korea.
authors.forename: So Hyun
authors.initials: SH
authors.lastname: Kwon
authors.affiliation: Department of Biology, Kyungpook National University, Daegu, 702-701, Korea.
authors.forename: Sang-Joo
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, 702-701, Korea.
authors.forename: Soon Ki
authors.initials: SK
authors.lastname: Park
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, 702-701, Korea.
authors.forename: Jong Tae
authors.initials: JT
authors.lastname: Song
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, 702-701, Korea.
authors.forename: Sangman
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Systems Biology, Yonsei University, Seoul, 120-749, Korea.
authors.forename: Myeong Min
authors.initials: MM
authors.lastname: Lee
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul, 143-701, Korea.
authors.forename: Yong-sic
authors.initials: YS
authors.lastname: Hwang
authors.affiliation: Department of Biology, Kyungpook National University, Daegu, 702-701, Korea. kimjeon4@knu.ac.kr.
authors.forename: Jeong Hoe
authors.initials: JH
authors.lastname: Kim
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant; D018816:Genes, cdc; D009154:Mutation; D018515:Plant Leaves / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C543686:NGA1 protein, Arabidopsis thaliana; C543687:NGA4 protein, Arabidopsis thaliana; D014157:Transcription Factors
keywords: Arabidopsis thaliana; B3 transcription factor; Cell proliferation; Lateral organs; NGATHA