Plants for Human Health Institute, North Carolina State University, 600 Laureate Way, Kannapolis, North Carolina 28081, USA.
USDA-ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Ave., Houston, TX 77030, USA.
Food Funct. 2023 Jul 31;14(15):7053-7065. doi: 10.1039/d2fo03606a.
Vitamin A, iron, and zinc deficiencies are major nutritional inadequacies in sub-Saharan Africa and disproportionately affect women and children. Biotechnology strategies have been tested to individually improve provitamin A carotenoid or mineral content and/or bioaccessibility in staple crops including sorghum (). However, concurrent carotenoid and mineral enhancement has not been thoroughly assessed and antagonism between these chemical classes has been reported. This work evaluated two genetically engineered constructs containing a suite of heterologous genes to increase carotenoid stability and pathway flux, as well as phytase to catabolize phytate and increase mineral bioaccessibility. Model porridges made from transgenic events were evaluated for carotenoid and mineral content as well as bioaccessibility. Transgenic events produced markedly higher amounts of carotenoids (26.4 μg g DW) compared to null segregants (4.2 μg g DW) and wild-type control (Tx430; 3.7 μg g DW). Phytase activation by pre-steeping flour resulted in significant phytate reduction (9.4 to 4.2 mg g DW), altered the profile of inositol phosphate catabolites, and reduced molar ratios of phytate to iron (16.0 to 4.1), and zinc (19.0 to 4.9) in engineered material, suggesting improved mineral bioaccessibility. Improved phytate : mineral ratios did not significantly affect micellarization and bioaccessible provitamin A carotenoids were over 23 times greater in transgenic events compared to corresponding null segregants and wild-type controls. A 200 g serving of porridge made with these transgenic events provide an estimated 53.7% of a 4-8-year-old child's vitamin A estimated average requirement. These data suggest that combinatorial approaches to enhance micronutrient content and bioaccessibility are feasible and warrant further assessment in human studies.
维生素 A、铁和锌的缺乏是撒哈拉以南非洲地区主要的营养不足，且 disproportionately 影响妇女和儿童。生物技术策略已被用于单独提高类胡萝卜素或矿物质含量和/或生物可利用性 staple crops，包括 sorghum (高粱)。然而，同时增强类胡萝卜素和矿物质的效果尚未得到充分评估，并且这些化学物质之间存在拮抗作用。这项工作评估了两个包含一系列异源基因的基因工程构建体，以提高类胡萝卜素的稳定性和途径通量，以及植酸酶以分解植酸盐并提高矿物质生物可利用性。用转基因事件制作的模型粥用于评估类胡萝卜素和矿物质含量以及生物可利用性。与 null segregants (4.2 μg g DW) 和 wild-type control (Tx430; 3.7 μg g DW) 相比，转基因事件产生的类胡萝卜素明显更高（26.4 μg g DW）。面粉预浸泡激活植酸酶导致植酸盐显著减少（9.4 至 4.2 mg g DW），改变了肌醇磷酸盐代谢物的谱，并降低了 engineered material 中植酸盐与铁（16.0 至 4.1）和锌（19.0 至 4.9）的摩尔比，表明矿物质生物可利用性提高。改善的植酸盐：矿物质比例并未显着影响胶束化，并且与相应的 null segregants 和 wild-type controls 相比，转基因事件中的生物可利用前维生素 A 类胡萝卜素增加了 23 倍以上。用这些转基因事件制作的 200 克粥估计可为 4 至 8 岁儿童提供维生素 A 估计平均需求量的 53.7%。这些数据表明，同时提高微量营养素含量和生物可利用性的组合方法是可行的，值得在人类研究中进一步评估。
