2020年2月29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Genomics（2023 IF=4.4）上发表了题为“Pigment variation and transcriptional response of the pigment synthesis pathway in the S2309 triple-color ornamental kale (Brassica oleracea L. var. acephala) line”的研究论文。论文第一作者为刘小萍硕士和张斌硕士（两人均已是博士），通讯作者为张扬勇研究员。

观赏羽衣甘蓝因其色彩鲜艳的叶子而广受欢迎，但对其变色机理的研究较少。本研究育成了三叶色观赏羽衣甘蓝品系(S2309)。对3种叶色类型的花青素、叶绿素、类胡萝卜素含量和RNA序列进行了分析。白叶和紫叶的叶绿素含量低于绿叶，而紫叶的花青素含量最高。在S2309_G与S2309_W的比较中，所有与叶绿素代谢相关的下调的DEG都被检测到，这表明叶绿素含量的下降主要是由于叶片由绿变白过程中对叶绿素生物合成的抑制所致。此外，参与花青素生物合成途径的19个DEGS的表达上调。这些结果为理解三色形成的机制提供了新的见解。

Fig. 1. Phenotype of S2309, bar = 1 cm. a: Nine-week stage. b: Eleven-week stage. c: Thirteen-week stage. d: Different (outer, middle and inner) leaves at the thirteen-week stage.

Fig. 2. Venn diagram showing the numbers of overlapping and nonoverlapping DEGs (false discovery rate [FDR] < 0.01 and fold change > 2.0 or < −2.0) within the three leaf color types. A: Specific genes in G vs. W, B: Specific genes in G vs. P, C: Specific genes in W vs. P, D: Specific overlapping genes in G vs. W and W vs. P, E: Specific overlapping genes in G vs. W and W vs. P, F: Specific overlapping genes in G vs. P and W vs. P, G: Overlapping genes in G vs. P, W vs. P and G vs. W. Information concerning the DEGs in the Venn diagram is shown in Supplementary Table S4.

Fig. 3. GO annotations of DEGs for the S2309_G vs. S2309_W and S2309_W vs. S2309_P comparisons. Blue: molecular function, Green: cellular component, Red: biological process. The Y-axis represents the GO terms; the X-axis represents the number of DEGs for each GO term. ‘*’ indicates significant enrichment of the GO term. a: GO annotations for the S2309_G vs. S2309_W comparison; b: GO annotations for the S2309_W vs. S2309_P comparison. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 4. Top 20 enriched pathways of the S2309_G vs. S2309_W and S2309_W vs. S2309_P comparisons. The Y-axis represents the pathway terms; the X-axis represents the degree of enrichment. The sizes of the points represent different numbers of DEGs, such that the larger the point is, the more DEGs there are. The colors represent different Q-values. a: Pathways for S2309_G vs. S2309_W; b: pathways for S2309_W vs. S2309_P. Q-value: corrected p-value, (Q-value < 0.01). Richfactor: the ratio of the number of DEGs annotated to the pathway term to the number of genes annotated to the pathway entry.

Fig. 5. Expression of genes involved in the chlorophyll and carotenoid biosynthesis pathways. a: Chlorophyll biosynthesis pathway; b: anthocyanin biosynthesis pathway; c: carotenoid biosynthesis pathway. The red color indicates upregulation, and the blue color indicates downregulation. The first column represents S2309_G vs. S2309_W, the second column represents S2309_G vs. S2309_W, and the third column represents S2309_W vs. S2309_P. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.