College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.
Hunan Engineering Laboratory for Good Agricultural Practice and Comprehensive Utilization of Famous-Region Medicinal Plants, Hunan Agricultural University, Changsha 410128, China.
J Agric Food Chem. 2021 May 19;69(19):5452-5462. doi: 10.1021/acs.jafc.0c06867. Epub 2021 May 9.
Fatty acid desaturase-2 (FAD2) is a key enzyme in the production of polyunsaturated fatty acids in plants. RNAi technology can reduce the expression of genes in seeds and acquire transgenic plants with a high oleic acid content, but the effect of seed-specific inhibition of expression on seed metabolites is not clear. Here we use widely targeted metabolomics to investigate the metabolites of normal-oleic-acid rapeseed (OA) and high-oleic-acid rapeseed (HOA) seeds, resulting in a total of 726 metabolites being detected. Among them, 24 differential metabolites were significantly downregulated and 88 differential metabolites were significantly upregulated in HOA rapeseed. In further lipid profile experiments, more lipids in seeds were accurately quantified. The contents of glycolipids and phospholipids that contain C18:1 increased significantly and C18:2 decreased because expression was inhibited. The changes in the expression of key genes in related pathways were also consistent with the changes in metabolites. The insertion site of the ihpRNA plant expression vector was reconfirmed through genomewide resequencing, and the transgenic event did not change the sequence of genes. There was no significant difference in the germination rate and germination potential between OA and HOA rapeseed seeds because the seed-specific ihpRNA plant expression vector did not affect other stages of plant growth. This work provides a theoretical and practical guidance for subsequent molecular breeding of high OA .
脂肪酸去饱和酶 2（FAD2）是植物中多不饱和脂肪酸生成的关键酶。RNAi 技术可以降低种子中基因的表达，获得油酸含量高的转基因植物，但种子特异性抑制表达对种子代谢物的影响尚不清楚。在这里，我们使用广泛靶向代谢组学来研究正常油酸油菜（OA）和高油酸油菜（HOA）种子的代谢物，共检测到 726 种代谢物。其中，HOA 油菜种子中有 24 种差异代谢物显著下调，88 种差异代谢物显著上调。在进一步的脂质谱实验中，对更多种子中的脂质进行了准确的定量。由于抑制了表达，含有 C18:1 的糖脂和磷脂的含量显著增加，而 C18:2 的含量显著减少。相关途径中关键基因的表达变化也与代谢物的变化一致。通过全基因组重测序重新确认了 ihpRNA 植物表达载体的插入位点，转基因事件没有改变基因的序列。OA 和 HOA 油菜种子的发芽率和发芽势没有显著差异，因为种子特异性 ihpRNA 植物表达载体不影响植物生长的其他阶段。这项工作为后续高 OA 的分子育种提供了理论和实践指导。
