|Ha, Chan Man - ARS-UCB PLNT GENE EXP CTR|
|Jun, Ji Hyung - ARS-UCB PLNT GENE EXP CTR|
|Nam, Hong Gil - POHANG U SCI/TECH S.KOREA|
Submitted to: Plant And Cell Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 15, 2004
Publication Date: November 15, 2004
Citation: Ha, C., Jun, J., Nam, H., Fletcher, J.C. 2004. BLADE-ON-PETIOLE1 encodes a BTB/POZ domain protein required for leaf morphogenesis in Arabidopsis thaliana. Plant and Cell Physiology, 45:1361-1370. Interpretive Summary: This article reports the cloning and expression pattern of a gene that is required for proper leaf formation during Arabidopsis development. The BLADE-ON-PETIOLE1 (BOP1) gene encodes a novel protein that contains two distinct domains, and is a member of a small gene family that includes a known disease resistance gene called NPR1. We show that the BOP1 gene is active beginning during the embryonic phase of development, where it is found at the base of the embryonic leaves. After germination, BOP1 is expressed at the base of all leaves, and later in young flower buds and at the base of the sepals and petals. Our findings identify a new gene that plays an important role in controlling leaf development.
Technical Abstract: The BLADE-ON-PETIOLE1 (BOP1) gene of Arabidopsis thaliana is required for proper leaf morphogenesis. BOP1 regulates leaf differentiation in a proximal-distal manner, and represses the expression of three class I knotted-like homeobox (knox) genes during leaf formation. Utilizing a map-based approach, we identified the molecular nature of the BOP1 gene, which encodes a BTB/POZ domain protein with ankyrin repeats. BOP1 is a member of a small gene family in Arabidopsis that includes the disease resistance regulatory protein NPR1. Insertions in and around BOP1 cause distinct lesions in leaf morphogenesis, revealing complex regulation of the locus. BOP1 transcripts are initially detectable in embryos, where they specifically localize to the base of the developing cotyledons near the SAM. During vegetative development, BOP1 is expressed in young leaf primordia and at the base of the rosette leaves on the adaxial side. During reproductive development, BOP1 transcripts are detected in young floral buds, and at the base of the sepals and petals. Our results indicate that BOP1 encodes a putative regulatory protein that modulates meristematic activity at discrete locations in developing lateral organs. This is the first report on a plant protein that plays a key role in morphogenesis with the distinctive combinatorial architecture of the BTB/POZ and ankyrin repeat domains.