- Jianli Liang (1)
- Bo Liu (1)
- José Manuel Franco-Zorrilla (1)
- Lin Meng (1)
- Salomé Prat (1)
- Xiaowu Wang (1)
- Jian Wu (1)
- Xueming Zhang (1)
Potato StCONSTANS-like1 Suppresses Storage Organ Formation by Directly Activating the FT-like StSP5G Repressor
Abelenda, José A. ; Cruz-Oró, Eduard ; Franco-Zorrilla, José Manuel ; Prat, Salomé - \ 2016
Current Biology 26 (2016)7. - ISSN 0960-9822 - p. 872 - 881.
CONSTANS - FLOWERING LOCUS T - potato - tuberigen
The CONSTANS-FT pathway defines a core module for reproductive transition in both long-day (LD) and short-day (SD) plants. Changes in the transcriptional function of the CONSTANS (CO) protein have been proposed to mediate differential SD activation of FLOWERING LOCUS T (FT) orthologs in SD plants. Potato Andigena genotypes have an obligate SD requirement for tuber formation, and this photoperiodic response correlates with activation of the FT StSP6A gene in leaves. The potato StCOL1 factor represses expression of this mobile tuberization signal, but the control mechanism is poorly understood. Here, we analyzed StCOL1 diurnal oscillation and protein accumulation at different photoperiods and light wavelengths. We observed that the potato StCOL1 gene peaked at dawn and that, in contrast to the Arabidopsis AtCO homolog, the light receptor phyB is necessary for protein stabilization in the light. Reduced StCOL1 levels in RNAi lines strongly correlated with downregulated expression of an additional potato FT family member, StSP5G. Co-regulated StCOL1 and StSP5G expression suggested that StCOL1 activates this target directly rather than controlling StSP6A expression. By hybridization of a universal protein-binding microarray, we established that StCOL1 binds a TGTGGT element, and we found that immunoprecipitated StCOL1 protein fractions were enriched in StSP5G promoter fragments bearing this element. We show that StSP5G represses tuberization in LD conditions and that this FT-like homolog suppresses StSP6A gene expression. Rewiring StCOL1 transcriptional function from direct activation of the StSP6A inducer signal to the control of an FT-like repressor thus mediates the strict SD requirement of Andigena plants for tuberization.
A transposon insertion in FLOWERING LOCUS T is associated with delayed flowering in Brassica rapa
Zhang, Xueming ; Meng, Lin ; Liu, Bo ; Hu, Yunyan ; Cheng, Feng ; Liang, Jianli ; Aarts, Mark G.M. ; Wang, Xiaowu ; Wu, Jian - \ 2015
Plant Science 241 (2015). - ISSN 0168-9452 - p. 211 - 220.
Brassica rapa - FLOWERING LOCUS T - Flowering time - Loss-of-function allele - Quantitative trait locus (QTL)
Long days and vernalization accelerate the transition from vegetative growth to reproductive growth in Brassica rapa. Bolting before plants reach the harvesting stage is a serious problem in B. rapa vegetable crop cultivation. The genetic dissection of flowering time is important for breeding of premature bolting-resistant B. rapa crops. Using a recombinant inbred line (RIL) population, we twice detected two major quantitative trait loci (QTLs) for flowering time in two different growing seasons that were located on chromosomes A02 and A07, respectively. We hypothesized that an orthologue of the Arabidopsis thaliana FLOWERING LOCUS T (FT) gene, named as BrFT2, was the candidate gene underlying the QTL localized to A07. A transposon insertion in the second intron of BrFT2 was detected in one of the parental lines, which was predicted to generate a loss-of-function allele. Transcription analysis revealed that the BrFT2 transcript was not present in the parental line that harbored the mutated allele. RILs carrying only the mutated BrFT2 allele showed delayed flowering regardless of growing seasons when compared to RILs carrying the wild-type BrFT2 allele. These data suggest that BrFT2 is involved in flowering time regulation in controlling flowering time in B. rapa.