Duplication and functional divergence of
TCP4
genes in turnip
Cheng Li, Caspar C. C. Chater, Hefan Li, Jiaying Gao, Yuanwen Duan, Yongping Yang, Xudong Sun Summary
Gene duplication is widely recognized as a significant catalyst for plant adaptive evolution. The retained duplicated genes usually undergo functional divergence to govern plant growth and stress resistance. Turnip (
Brassica rapa
var.
rapa
) shows a broad capacity for environmental adaptation. Here, we investigate how duplicated
TCP4
genes modulate turnip growth and development.
We identify three
TCP4
paralogs,
BrrTCP4
,
BrrTCP4a
and
BrrTCP4b
in turnip, characterize their expression patterns and analyze sequence variation in their conserved domains. We further model their three‐dimensional structures and compare their protein–protein interactions and downstream regulatory networks.
We show that
BrrTCP4
,
BrrTCP4a
and
BrrTCP4b
exhibit distinct expression profiles. A single mutation within the conserved TCP domain leads to differences in protein–protein interactions among BrrTCP4, BrrTCP4a and BrrTCP4b. Combined with DAP‐Seq, ChIP‐qPCR and luciferase assays, our results demonstrate that BrrTCP4 and BrrTCP4a activate
BrrCOs
and
BrrFTs
to regulate turnip flowering, while BrrTCP4b preferentially participates in the trehalose synthesis pathway by targeting
TPP
and
TPS
genes.
Our research findings indicate the functional divergence of
BrrTCP4
,
BrrTCP4a
and
BrrTCP4b
to balance growth and stress responses in turnip, thereby advancing our understanding of how gene duplication drives functional specialization and contributes to plant evolutionary adaptation.