Plant Breeding Institute, Christian-Albrechts-University of Kiel, Kiel, Germany.
Institute of Crop Science, Zhejiang University, Hangzhou, China.
Plant Biotechnol J. 2020 Nov;18(11):2251-2266. doi: 10.1111/pbi.13381. Epub 2020 Apr 13.
Plant-based oils are valuable agricultural products, and seed oil content (SOC) is the major yield component in oil crops. Increasing SOC has been successfully targeted through the selection and genetic modification of oil biosynthesis. The SOC in rapeseed declined during the seed maturation and eventually caused the final accumulated seed oil quantity. However, genes involved in oil degradation during seed maturity are not deeply studied so far. We performed a candidate gene association study using a worldwide collection of rapeseed germplasm. We identified SEED FATTY ACID REDUCER (SFAR) genes, which had a significant effect on SOC and fatty acid (FA) composition. SFAR genes belong to the GDSL lipases, and GDSL lipases have a broad range of functions in plants. After quantification of gene expression using RNA-seq and quantitative PCR, we used targeted (CRISPR-Cas mediated) and random (chemical) mutagenesis to modify turnover rates of seed oil in winter rapeseed. For the first time, we demonstrate significant increase of SOC in a crop after knocking out members of the BnSFAR4 and BnSFAR5 gene families without pleiotropic effects on seed germination, vigour and oil mobilization. Our results offer new perspectives for improving oil yield by targeted mutagenesis.
植物油脂是有价值的农产品，而种子含油量（SOC）是油料作物的主要产量构成因素。通过对油脂生物合成的选择和遗传修饰，已经成功地将 SOC 增加作为目标。油菜籽的 SOC 在种子成熟过程中下降，最终导致最终积累的种子油量减少。然而，迄今为止，参与种子成熟过程中油脂降解的基因尚未得到深入研究。我们使用全球油菜种质资源进行了候选基因关联研究。我们鉴定了种子脂肪酸还原酶（SFAR）基因，这些基因对 SOC 和脂肪酸（FA）组成有显著影响。SFAR 基因属于 GDSL 脂肪酶，GDSL 脂肪酶在植物中有广泛的功能。使用 RNA-seq 和定量 PCR 对基因表达进行定量后，我们使用靶向（CRISPR-Cas 介导）和随机（化学）诱变来改变冬油菜种子的油脂周转率。我们首次证明，在不影响种子发芽、活力和油脂动员的情况下，敲除 BnSFAR4 和 BnSFAR5 基因家族的成员后，作物的 SOC 显著增加。我们的研究结果为通过靶向诱变提高油产量提供了新的视角。
