Determinate inflorescence is indeed a pivotal agricultural characteristic in crops, notably impacting the architecture modification of
Brassica napus
(AACC, 2n = 38). Previous study identified a crucial gene
Bnsdt2
that encodes the transcription factor
BnaC09.TFL1
(
Terminal Flower 1
). Here by two alleles were cloned and sequenced from indeterminate 2982 and determinate 4769, respectively, we found that
BnaC09.TFL1
harbors two T/C and G/C non-synonymous mutations in exon 1, and contains sixty-six differences in a 1.9 Kb promoter sequence. Subsequently,
BnaC09.TFL1
was introduced into
B. napus
571 line by genetic complementation and overexpression, transgenic plants 571
CTO
lines and 571
TC
lines were all restored to the indeterminate inflorescence. Interestingly, after
BnaC09.TFL1
was knocked out in ‘Westar’, transgenic plants Westar
Tcr
lines were mutated to determinate inflorescences. Additionally, a NIL-4769 line was constructed to evaluate the effect of
BnaC09.TFL1
on agronomic traits of
Brassica napus
, the results demonstrated that
BnaC09.tfl1
reduced the plant height and increased the branch number and branch thousand grain weight of
Brassica napus.
Finally, we performed RT-qPCR, GUS staining and subcellular localization experiments to analyze the expression pattern of
BnaC09.TFL1
, the results showed that the expression of
BnaC09.TFL1
at shoot apex of NIL-4769 was higher than that of 4769, GUS activity was detected at apical of
Arabidopsis thaliana
and
BnC09.TFL1-GFP
was detected in cell membrane, nucleus and cytoplasm. Our findings provide a firm molecular foundation for the study of rapeseed’s molecular mechanism of determinate inflorescence formation, as well as theoretical guidance for the application of determinate inflorescence in rapeseed breeding.
Supplementary Information
The online version contains supplementary material available at 10.1007/s11032-024-01503-7.
