Targeted Knockout of BnTT2 Homologues for Yellow-Seeded Brassica napus with Reduced Flavonoids and Improved Fatty Acid Composition.
Authors: Xie Tao, Chen Xin, Guo Tuli, Rong Hao, Chen Ziyi, Sun Qinfu, Batley Jacqueline, Jiang Jinjin, Wang Youping
Journal: Journal of agricultural and food chemistry (J Agric Food Chem), Vol.68(20), 2020‑May‑20
DOI:
10.1021/acs.jafc.0c01126
Abstract
Brassica napus is 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 two BnTT2 homologues were knocked out, indicating that the two BnTT2 homologues had conserved but redundant functions in regulating seed color. Histochemical staining and flavonoid metabolic analysis proved that the BnTT2 mutation hindered the synthesis and accumulation of proanthocyanidins. Transcriptome analysis also showed that the BnTT2 mutation 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 of BnTT2 homologues 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 the BnTT2 mutation can be used for yellow seed breeding and oil improvement, which is of great significance in improving the economic value of rapeseeds.
Publication Types
Journal Article
Keywords
Brassica napus
CRISPR/Cas9
TRANSPARENT TESTA 2
fatty acid
flavonoids
yellow seed
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