Biotechnology Research Center, Chongqing Key Laboratory of Application and Safety Control of Genetically Modified Crops, Southwest University, Beibei, Chongqing, 400715, China.
Sci Rep. 2018 Jan 22;8(1):1348. doi: 10.1038/s41598-018-19866-1.
Provitamin A (PVA) bio-fortification of crops offers a sustainable strategy to prevent the prevalence of vitamin A deficiency (VAD), one of the world's major public health problems. The present work aimed to enhance PVA accumulation in cottonseed, the main by-product in the production of cotton fibers and the third largest source of edible plant oil in the world. On the basis of comprehensive identification of carotenoid synthase genes and their expression levels in various cotton tissues, we selected phytoene synthase as the target for manipulating carotenoid biosynthesis in the developing cottonseeds. After functional verification in transgenic tobacco, a cotton phytoene synthase gene (GhPSY2D) driven by a seed-specific promoter was transformed into cotton. The transgenic cottonseeds showed golden appearance and contained over 6-fold higher carotenoid contents in the extracted oil than the non-transgenic control. Thin layer chromatograph analysis indicated that the main PVA carotenoid β-carotene was predominant in the transgenic cottonseeds, but undetectable in the wild-type control. By simultaneously providing economically valuable fibers and edible oils, the transgenic cottons bio-fortified with β-carotene in seeds may be a new powerful tool against VAD in low-income regions.
类胡萝卜素前体（PVA）生物强化作物为预防维生素 A 缺乏症（VAD）的流行提供了一种可持续策略，VAD 是世界上主要的公共卫生问题之一。本研究旨在提高棉籽中的 PVA 积累，棉籽是生产棉纤维的主要副产物，也是世界上第三大食用植物油来源。在综合鉴定各种棉组织中的类胡萝卜素合酶基因及其表达水平的基础上，我们选择了八氢番茄红素合酶作为操纵发育中棉籽类胡萝卜素生物合成的目标基因。在转基因烟草中进行功能验证后，我们将一个由种子特异性启动子驱动的棉花八氢番茄红素合酶基因（GhPSY2D）转化到棉花中。与非转基因对照相比，转基因棉籽外观呈金黄色，提取油中的类胡萝卜素含量高出 6 倍以上。薄层色谱分析表明，主要的 PVA 类胡萝卜素β-胡萝卜素在转基因棉籽中占优势，但在野生型对照中无法检测到。通过同时提供经济价值高的纤维和食用油，种子中富含β-胡萝卜素的转基因棉花可能成为对抗低收入地区 VAD 的一种新的有力工具。
