Independent activation of the BoMYB2 gene leading to purple traits in Brassica oleracea
Independent activation of the BoMYB2 gene leading to purple traits in Brassica oleracea
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BoMYB2 基因的独立激活导致甘蓝紫色性状。
DOI：
10.1007/s00122-018-3245-9
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发表时间：
2019-04-01
影响因子：
5.4
通讯作者：
Kuang, Hanhui
中科院分区：
文献类型：
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作者：
Yan, Chenghuan;An, Guanghui;Kuang, Hanhui
转座子插入和点突变分别激活了甘蓝、大头菜和白菜等3个紫色甘蓝品种的BoMYB2基因。摘要部分甘蓝品种既有绿色品种，也有紫色品种。本研究利用图谱克隆方法克隆了甘蓝、大头菜和大白菜紫色性状的致病基因。这3个品种的紫色性状与菜花中的BoMYB2基因定位在同一个位点上。令人惊讶的是，在花椰菜中没有发现BoMYB2的Harbinger转座子插入，而在紫甘蓝、大头菜和卷心菜中没有发现。对紫色羽衣甘蓝和紫色大头菜的BoMYB2基因进行测序，发现其启动子区有一个7606bp的cacta样转座子。瞬时分析和启动子活性研究表明，插入上调了BoMYB2基因的表达。另一方面，紫色卷心菜BoMYB2基因的激活是由点突变和/或在其启动子区域插入1 bp引起的。对不同品种BoMYB2基因的序列分析表明，激活事件很可能是在白菜、花椰菜和甘蓝/甘蓝分化后独立发生的。本研究结果不仅有助于更好地了解甘蓝花青素的遗传，而且为今后紫色品种BoMYB2基因不同功能等位基因的组合育种提供了有用的信息。
Key messageTransposon insertion and point mutation independently activated the BoMYB2 gene in three purple cultivars of Brassica oleracea including kale, kohlrabi, and cabbage.AbstractSeveral varieties of B. oleracea have both green and purple cultivars. In this study, the causal genes for the purple traits in kale, kohlrabi and cabbage were cloned using map-based cloning approach. The purple traits in all three varieties were mapped to the same locus as the BoMYB2 gene in cauliflower. Surprisingly, the insertion of Harbinger transposon of BoMYB2 in cauliflower was not found in purple kale, kohlrabi and cabbage. Sequencing of the BoMYB2 gene in purple kale and purple kohlrabi discovered a 7606bp CACTA-like transposon in its promoter region. Transient assay and promoter activity study showed that the insertion upregulated the expression of the BoMYB2 gene. On the other hand, the activation of the BoMYB2 gene in purple cabbage was caused by point mutation and/or 1-bp insertion in its promoter region. Sequence analysis of the BoMYB2 gene in different varieties suggested that the activating events most likely occurred independently after the divergence of cabbage, cauliflower, and kale/kohlrabi. Our results not only contribute to a better understanding of anthocyanin inheritance in B. oleracea, but also provide useful information for future hybrid breeding of purple cultivars through combination of different functional alleles of the BoMYB2 gene.