Non-cell-autonomously coordinated organ size regulation in leaf development.
Kensuke Kawade1, Gorou Horiguchi, Hirokazu Tsukaya
1Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Development (Cambridge, England)
|November 12, 2010
Summary
Plant organ size is controlled by cell proliferation and expansion. ANGUSTIFOLIA3 (AN3) mutation triggers non-cell-autonomous compensation via intercellular signals, while KIP-RELATED PROTEIN2 overexpression causes cell-autonomous compensation, revealing new pathways for organ size regulation.
Area of Science:
- Plant biology
- Developmental biology
- Genetics
Background:
- Organ size control is a fundamental challenge in biology.
- Compensation, where reduced cell proliferation triggers cell expansion, is a key but poorly understood phenomenon in organogenesis.
- Coordination of cellular processes like proliferation and expansion is crucial for organ size regulation.
Purpose of the Study:
- To investigate the mechanisms underlying compensation in Arabidopsis thaliana leaf development.
- To determine whether AN3-dependent compensation is cell-autonomous or non-cell-autonomous.
- To identify intercellular signaling pathways involved in coordinating cell proliferation and expansion for organ size control.
Main Methods:
- Utilized a loss-of-function mutation in the ANGUSTIFOLIA3 (AN3) gene.
- Established Cre/lox systems to create chimeric leaves for AN3 expression analysis.
- Investigated the effect of KIP-RELATED PROTEIN2 overexpression on compensation.
Main Results:
- AN3-dependent compensation was identified as a non-cell-autonomous process.
- AN3-mutant cells appear to transmit an intercellular signal promoting postmitotic cell expansion.
- The signaling range for AN3-dependent compensation was observed to be within one-half of the leaf, delimited by the midrib.
- Overexpression of KIP-RELATED PROTEIN2 led to cell-autonomous compensation.
Conclusions:
- Discovered two distinct pathways regulating organ size control in plants.
- Demonstrated that AN3 mediates organ size control through non-cell-autonomous signaling.
- Showed that KIP-RELATED PROTEIN2 functions in a cell-autonomous manner for compensation.
- Provided new insights into the coordination of cell proliferation and expansion during plant organogenesis.
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