Evolutionary analyses and expression patterns of TCP genes in Ranunculales

Area of Science:

• Plant developmental biology
• Molecular evolution
• Genomics

Background:

• TCP transcription factors regulate diverse plant developmental processes.
• Characterization of TCP gene families is incomplete in early diverging eudicots.
• Ranunculales, an early diverging eudicot order, exhibits significant morphological diversity.

Purpose of the Study:

• To characterize the TCP gene repertoire in an early diverging eudicot species, *Nigella damascena*.
• To investigate the evolutionary history and diversification of TCP genes within angiosperms.
• To analyze the expression patterns of TCP genes in *Nigella damascena* floral tissues.

Main Methods:

• Phylogenetic analysis of TCP genes from *Nigella damascena* and *Aquilegia coerulea*.
• Identification of conserved amino acid motifs within TCP protein families.
• Transcriptome analysis to determine TCP gene expression patterns in *Nigella damascena* flowers.

Main Results:

• All identified TCP genes in *Nigella damascena* are orthologous to those in *Aquilegia coerulea*.
• Six paralogous class I TCP genes were likely present in the common ancestor of angiosperms.
• Independent gene duplications in core eudicots and Ranunculales contributed to differential TCP gene family expansion.
• Expression patterns suggest redundant roles for CIN and class I TCP genes, and specific roles for CYC/TB1 genes.

Conclusions:

• The study provides the first comprehensive characterization of TCP genes in an early diverging eudicot.
• Evolutionary analyses reveal conserved ancestral TCP genes and lineage-specific duplications.
• Findings shed light on the functional diversification of TCP genes and their role in plant morphological evolution.