Differential Recruitment of WOX Transcription Factors for Lateral Development and Organ Fusion in Petunia and Arabidopsis

• Published in: The Plant cell Vol. 21; no. 8; pp. 2269 - 2283
• Main Authors: Vandenbussche, Michiel, Horstman, Anneke, Zethof, Jan, Koes, Ronald, Rijpkema, Anneke S, Gerats, Tom
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Biologists 01.08.2009
• Subjects: Alleles; Amino Acid Sequence; Arabidopsis; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis - ultrastructure; Arabidopsis Proteins; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Carpels; chemistry; corolla; Cryoelectron Microscopy; Flowers; Flowers - genetics; Flowers - growth & development; Flowers - metabolism; Flowers - ultrastructure; Genes; genetics; growth & development; In Situ Hybridization; Leaf blade; Leaves; metabolism; Molecular Sequence Data; mutants; Petals; Petunia; Petunia - genetics; Petunia - growth & development; Petunia - metabolism; Petunia - ultrastructure; Petunia hybrida; Phenotypes; Phylogeny; Plant cells; Plant Leaves; Plant Leaves - genetics; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant Leaves - ultrastructure; Plant Proteins; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Reverse Transcriptase Polymerase Chain Reaction; transcription factors; Transcription Factors - chemistry; Transcription Factors - genetics; Transcription Factors - metabolism; Transposons; ultrastructure
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.109.065862

Petal fusion in petunia (Petunia x hybrida) results from lateral expansion of the five initially separate petal primordia, forming a ring-like primordium that determines further development. Here, we show that MAEWEST (MAW) and CHORIPETALA SUZANNE (CHSU) are required for petal and carpel fusion, as well as for lateral outgrowth of the leaf blade. Morphological and molecular analysis of maw and maw chsu double mutants suggest that polarity defects along the adaxial/abaxial axis contribute to the observed reduced lateral outgrowth of organ primordia. We show that MAW encodes a member of the WOX (WUSCHEL-related homeobox) transcription factor family and that a partly similar function is redundantly encoded by WOX1 and PRESSED FLOWER (PRS) in Arabidopsis thaliana, indicating a conserved role for MAW/WOX1/PRS genes in regulating lateral organ development. Comparison of petunia maw and Arabidopsis wox1 prs phenotypes suggests differential recruitment of WOX gene function depending on organ type and species. Our comparative data together with previous reports on WOX gene function in different species identify the WOX gene family as highly dynamic and, therefore, an attractive subject for future evo-devo studies.