Arabidopsis thaliana NGATHA transcription factors negatively regulate cell proliferation of lateral organs

• Published in: Plant molecular biology Vol. 89; no. 4-5; pp. 529 - 538
• Main Authors: Lee, Byung Ha, Kwon, So Hyun, Lee, Sang-Joo, Park, Soon Ki, Song, Jong Tae, Lee, Sangman, Lee, Myeong Min, Hwang, Yong-sic, Kim, Jeong Hoe
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.11.2015; Springer Nature B.V
• Subjects: Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biochemistry; Biomedical and Life Sciences; cell cycle; Cell growth; cell proliferation; Cell Proliferation - genetics; Cell Proliferation - physiology; flowers; genes; Genes, cdc; Genes, Plant; growth and development; leaves; Life Sciences; Mutants; Mutation; Organs; Plant biology; Plant Leaves - cytology; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant Pathology; Plant Sciences; Plants, Genetically Modified; transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Cell proliferation; Lateral organs; NGATHA; B3 transcription factor; Arabidopsis thaliana
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/s11103-015-0386-y

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.