Targeted knockout of BnTT2 homologues for yellow-seeded Brassica napus with reduced flavonoids and improved fatty acid composition
Targeted knockout of BnTT2 homologues for yellow-seeded Brassica napus with reduced flavonoids and improved fatty acid composition
复制标题
靶向敲除黄籽甘蓝型油菜的 BnTT2 同源物，减少类黄酮并改善脂肪酸组成
DOI：
10.1021/acs.jafc.0c01126
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发表时间：
2020
影响因子：
6.1
通讯作者：
Wang Youping
中科院分区：
文献类型：
--
作者：
Xie Tao;Chen Xin;Guo Tuli;Rong Hao;Chen Ziyi;Sun Qinfu;Batley Jacqueline;Jiang Jinjin;Wang Youping
甘蓝型油菜是世界范围内重要的油料作物之一，提高油品品质是油菜育种的主要目标。黄种子是一种优良性状，在提高种子品质和经济价值方面具有巨大潜力。在本研究中，我们利用CRISPR/Cas9系统创建了稳定的黄色种子突变体，并且仅当两个BnTT2同源物的四个等位基因被敲除时才获得黄色种子表型，这表明两个BnTT2同源物在调节种子颜色方面具有保守但冗余的功能。组织化学染色和类黄酮代谢分析证明BnTT2突变阻碍了原花青素的合成和积累。转录组分析还表明，BnTT2突变抑制了苯丙素和类黄酮生物合成途径中基因的表达，这可能是由BnTT2、BnTT8和BnTTG1复合物调控的。此外，BnTT2同系物纯合突变体的含油量增加，脂肪酸组成改善，亚油酸(C18:2)和亚麻酸(C18:3)含量较高，可用于油菜遗传改良。总体而言，本研究表明BnTT2突变可用于黄籽育种和油料改良，对于提高油菜籽的经济价值具有重要意义。
Brassica napusis one of the important oil crops grown worldwide, and oil quality improvement is a major goal in rapeseed breeding. Yellow seed is an excellent trait, which has great potential in improving seed quality and economic value. In this study, we created stable yellow seed mutants using a CRISPR/Cas9 system and obtained the yellow seed phenotype only when the four alleles of twoBnTT2homologues were knocked out, indicating that the twoBnTT2homologues had conserved but redundant functions in regulating seed color. Histochemical staining and flavonoid metabolic analysis proved that theBnTT2mutation hindered the synthesis and accumulation of proanthocyanidins. Transcriptome analysis also showed that theBnTT2mutation inhibited the expression of genes in the phenylpropanoid and flavonoid biosynthetic pathway, which might be regulated by the complex of BnTT2, BnTT8 and BnTTG1. In addition, the homozygous mutants ofBnTT2homologues increased oil content and improved fatty acid composition with higher linoleic acid (C18:2) and linolenic acid (C18:3), which could be used for the genetic improvement of rapeseed. Overall, this research showed that theBnTT2mutation can be used for yellow seed breeding and oil improvement, which is of great significance in improving the economic value of rapeseeds.