2023年9月28日，中国农业科学院蔬菜花卉研究所甘蓝青花菜研究团队在期刊plants（2023IF=4.5）上发表了题为Transcriptome Analysis Reveals Key Genes and Pathways Associated with the Regulation of Flowering Time in Cabbage (Brassica oleracea L. var. capitata)的研究论文，论文第一作者为王娇硕士和张斌博士，通讯作者为张扬勇研究员。

开花时间是甘蓝的重要农艺性状，但是甘蓝开花时间调控的分子机制尚不清楚。作者利用两组甘蓝材料 （1）早花自交系C491（P1）和晚花自交系B602（P2），（2）来自F2群体的早花单株F2-B和晚花单株F2-NB进行转录组分析。分析发现C491 VS B602和F2-B VS F2-NB共有9508个差异表达基因。GO和KEGG分析表明上调基因主要富集在植物激素信号转导和MAPK信号通路，下调基因主要富集在核糖体、DNA复制途径中。

随后作者在甘蓝中鉴定了321个拟南芥开花基因（Ft）的同源基因。其中两组对照材料中共检测到25个差异表达基因（11个上调和14个下调），其中12个基因的表达图谱和两组材料不同开花时间密切对应。QRT-PCR分析表明，编码MADS-box蛋白的两个基因Bo1g157450(BoSEP2-1)和Bo5g152700(BoSEP2-2)在晚花亲本B602中的表达显著低于早花亲本C491，这与RNA-seq数据一致。其次，分析了Bo1g157450(BoSEP2-1)和Bo5g152700(BoSEP2-2)在早花和晚花单株中的表达水平，结果表明它们的表达模式与亲本一致。序列分析表明，Bo1g157450(BoSEP2-1)和Bo5g152700(BoSEP2-2)分别存在3个和1个位于B602和C491之间的SNPs。因此，BoSEP2-1和BoSEP2-2被认为是通过潜在的新的调控途径来调控开花时间的候选基因。

Figure 1. Phenotypes of C491 and B602 at 41 days after vernalization. (a) C491 is early-flowering.
(b) B602 is late-flowering. Bar = 5 cm.

Figure 2. Comparison of differentially expressed genes response to vernalization between C491_VS_B602 and F2-B_VS_F2-NB. (a) V enn diagram showing the numbers of up- and down-regulated overlapping DEGs in C491_VS_B602 and F2-B_VS_F2-NB, respectively . (b) Top 20 enriched GO terms for up- and down-regulated overlapping DEGs in both C491_VS_B602 and F2-B_VS_F2-NB. (c) Top 20 enriched KEGG pathways for up- and down-regulated DEGs in both C491_VS_B602 and F2-B_VS_F2-NB.

Figure 3. Heatmap showing the gene expression of 25 flowering-related DEGs. The intensity of the color for each gene model corresponds to the average fragments per kilobase of transcript per million mapped reads (FPKM) values. The asterisks represent significant differences (p < 0.01).

Figure 4. Validation of 25 DEGs related to flowering time via qRT‒PCR. (a) The relative expression
levels of 11 up‐regulated DEGs related to flowering time in early‐flowering C491 and late‐flowering
B602. (b) The relative expression levels of 14 down‐regulated DEGs related to flowering time in
early‐flowering C491 and late‐flowering B602. ** indicates a significant difference (p < 0.01).

Figure 5. CDS sequence difference of the genes Bo5g152700 (BoSEP2‐1) and Bo1g157450 (BoSEP2‐2)
between C491 and B602. (a) CDS sequence difference of the gene Bo5g152700 (BoSEP2‐1) between
Figure 5. CDS sequence difference of the genes Bo5g152700 (BoSEP2-1) and Bo1g157450 (BoSEP2-2)
between C491 and B602. (a) CDS sequence difference of the gene Bo5g152700 (BoSEP2-1) between
C491 and B602. (b) CDS sequence difference of the gene Bo1g157450 (BoSEP2-2) between C491 and
B602. The red bases represent consistency between the parents, while the blue and black bases
represent sequence differences between the parents.

Figure 6. Potential flowering time regulatory networks in cabbage. Genes in blue represent flowering repressors, and genes in black represent flowering promoters. The genes in the black box have regulatory interactions that have been reported before, and the genes in the pink box are candidates. The arrows indicate transcriptional activation, whereas the bars indicate transcriptional repression. The dashed line represents the putative regulatory pathway