State Key Laboratory of Crop Stress Biology for Arid Areas, National Yangling Agricultural Biotechnology & Breeding Center, Shaanxi Key Laboratory of Crop Heterosis and College of Agronomy, Northwest A&F University, Yangling 712100, China.
Int J Mol Sci. 2022 Dec 14;23(24):15933. doi: 10.3390/ijms232415933.
Rapeseed ( L.) is an important oil crop and a major source of tocopherols, also known as vitamin E, in human nutrition. Enhancing the quality and composition of fatty acids (FAs) and tocopherols in seeds has long been a target for rapeseed breeding. The gene () encodes an enzyme catalysing the conversion of γ-tocopherol to α-tocopherol, which has the highest biological activity. However, the genetic basis of in seeds remains unclear. In the present study, , one paralogue of , was isolated from the cultivar "Zhongshuang11" by nested PCR, and two homozygous transgenic overexpression lines were further characterised. Our results demonstrated that the overexpression of mediated an increase in the α- and total tocopherol content in transgenic seeds. Interestingly, the FA composition was also altered in the transgenic plants; a reduction in the levels of oleic acid and an increase in the levels of linoleic acid and linolenic acid were observed. Consistently, promoted the expression of and , which are involved in the biosynthesis of polyunsaturated fatty acids during seed development. In addition, enhanced the tolerance to salt stress by scavenging reactive oxygen species (ROS) during seed germination in . Our results suggest that could affect the tocopherol content and FA composition and play a positive role in regulating the rapeseed response to salt stress by modulating the ROS scavenging system. This study broadens our understanding of the function of the gene and provides a novel strategy for genetic engineering in rapeseed breeding.
油菜（ L.）是一种重要的油料作物，也是人类营养中生育酚（又称维生素 E）的主要来源。长期以来，提高种子中脂肪酸（FAs）和生育酚的质量和组成一直是油菜育种的目标。基因（）编码一种酶，该酶催化γ-生育酚转化为具有最高生物活性的α-生育酚。然而，种子中基因的遗传基础仍不清楚。在本研究中，通过巢式 PCR 从油菜品种“中双 11”中分离出基因的一个同源物（），并进一步对两个纯合转基因过表达系进行了特征分析。我们的结果表明，过表达可增加转基因油菜种子中α-和总生育酚的含量。有趣的是，转基因植株的脂肪酸组成也发生了变化；观察到油酸水平降低，亚油酸和亚麻酸水平升高。一致地，基因促进了参与种子发育过程中多不饱和脂肪酸生物合成的基因和的表达。此外，通过在种子萌发过程中清除活性氧（ROS），基因增强了对盐胁迫的耐受性。我们的结果表明，基因可能通过调节 ROS 清除系统影响生育酚含量和 FA 组成，并在调控油菜对盐胁迫的响应中发挥积极作用。本研究拓宽了我们对基因功能的理解，并为油菜遗传育种中的基因工程提供了一种新策略。
