Arabidopsis lateral organ boundaries negatively regulates brassinosteroid accumulation to limit growth in organ boundaries

Bell, E. M., Lin, W. C., Husbands, A. Y., Yu, L., Jaganatha, V., Jablonska, B., Mangeon, A., Neff, M. M., Girke, T., Springer, P. S. (December 2012) Arabidopsis lateral organ boundaries negatively regulates brassinosteroid accumulation to limit growth in organ boundaries. Proceedings of the National Academy of Sciences of the United States of America, 109 (51). pp. 21146-21151. ISSN 00278424

[thumbnail of Paper]
PDF (Paper)
Husbands PNAS 2012.pdf - Published Version

Download (874kB) | Preview
DOI: 0.1073/pnas.1210789109


Leaves and flowers begin life as outgrowths from the edges of shoot apical meristems. Stem cell divisions in the meristem center replenish cells that are incorporated into organ primordia at the meristem periphery and leave the meristem. Organ boundaries, regions of limited growth that separate forming organs from the meristem, serve to isolate these two domains and are critical for coordination of organogenesis and meristem maintenance. Boundary formation and maintenance are poorly understood processes, despite the identification of a number of boundary-specific transcription factors. Here we provide genetic and biochemical evidence that the Arabidopsis thaliana transcription factor LATERAL ORGAN BOUNDARIES (LOB) negatively regulates accumulation of the plant steroid hormone brassinosteroid (BR) in organ boundaries. We found that ectopic expression of LOB results in reduced BR responses. We identified BAS1, which encodes a BR-inactivating enzyme, as a direct target of LOB transcriptional activation. Loss-of-function lob mutants exhibit organ fusions, and this phenotype is suppressed by expression of BAS1 under the LOB promoter, indicating that BR hyperaccumulation contributes to the lob mutant phenotype. In addition, LOB expression is BR regulated; therefore, LOB and BR form a feedback loop to modulate local BR accumulation in organ boundaries to limit growth in the boundary domain.

Item Type: Paper
Subjects: organism description > plant > Arabidopsis
organism description > plant
CSHL Authors:
Communities: CSHL labs > Timmermans lab
CSHL Post Doctoral Fellows
Depositing User: Matt Covey
Date: 18 December 2012
Date Deposited: 31 Jan 2013 21:18
Last Modified: 22 Dec 2017 17:13
PMCID: PMC3529045
Related URLs:

Actions (login required)

Administrator's edit/view item Administrator's edit/view item
CSHL HomeAbout CSHLResearchEducationNews & FeaturesCampus & Public EventsCareersGiving