Tan Grace Z H, Das Bhowmik Sudipta S, Hoang Thi M L, Karbaschi Mohammad R, Long Hao, Cheng Alam, Bonneau Julien P, Beasley Jesse T, Johnson Alexander A T, Williams Brett, Mundree Sagadevan G
Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, QLD, Australia.
School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.
Front Plant Sci. 2018 Jun 14;9:788. doi: 10.3389/fpls.2018.00788. eCollection 2018.
Iron deficiency currently affects over two billion people worldwide despite significant advances in technology and society aimed at mitigating this global health problem. Biofortification of food staples with iron (Fe) represents a sustainable approach for alleviating human Fe deficiency in developing countries, however, biofortification efforts have focused extensively on cereal staples while pulses have been largely overlooked. In this study we describe a genetic engineering (GE) approach to biofortify the pulse crop, chickpea ( L.), with Fe using a combination of the chickpea nicotianamine synthase 2 () and soybean () ferritin () genes which function in Fe transport and storage, respectively. This study consists of three main components: (1) the establishment for baseline Fe concentration of existing germplam, (2) the isolation and study of expression pattern of the novel gene, and (3) the generation of GE chickpea overexpressing the and genes. Seed of six commercial chickpea cultivars was collected from four different field locations in Australia and assessed for seed Fe concentration. The results revealed little difference between the cultivars assessed, and that chickpea seed Fe was negatively affected where soil Fe bioavailability is low. The desi cultivar HatTrick was then selected for further study. From it, the gene was cloned and its expression in different tissues examined. The gene was found to be expressed in multiple vegetative tissues under Fe-sufficient conditions, suggesting that it may play a housekeeping role in systemic translocation of Fe. Two GE chickpea events were then generated and the overexpression of the and transgenes confirmed. Analysis of nicotianamine (NA) and Fe levels in the GE seeds revealed that NA was nearly doubled compared to the null control while Fe concentration was not changed. Increased NA content in chickpea seed is likely to translate into increased Fe bioavailability and may thus overcome the effect of the bioavailability inhibitors found in pulses; however, further study is required to confirm this. This is the first known example of GE Fe biofortified chickpea; information gleaned from this study can feed into future pulse biofortification work to help alleviate global Fe deficiency.
尽管在技术和社会方面取得了显著进步，旨在缓解这一全球健康问题，但缺铁目前仍影响着全球超过20亿人口。通过铁（Fe）对主粮进行生物强化是发展中国家缓解人类缺铁问题的一种可持续方法，然而，生物强化工作主要集中在谷类主粮上，而豆类基本上被忽视了。在本研究中，我们描述了一种基因工程（GE）方法，利用鹰嘴豆烟酰胺合酶2（）和大豆（）铁蛋白（）基因的组合对豆类作物鹰嘴豆（L.）进行铁生物强化，这两个基因分别在铁运输和储存中发挥作用。本研究包括三个主要部分：（1）确定现有种质的铁浓度基线，（2）分离并研究新的基因的表达模式，（3）培育过表达和基因的基因工程鹰嘴豆。从澳大利亚四个不同田间地点收集了六个商业鹰嘴豆品种的种子，并对种子铁浓度进行了评估。结果显示，所评估的品种之间差异不大，并且在土壤铁生物有效性较低的地方，鹰嘴豆种子铁受到负面影响。然后选择了迪西品种HatTrick进行进一步研究。从中克隆了基因并检测了其在不同组织中的表达。发现该基因在铁充足条件下在多个营养组织中表达，这表明它可能在铁的系统转运中起看家作用。然后产生了两个基因工程鹰嘴豆事件，并证实了和转基因的过表达。对基因工程种子中的烟酰胺（NA）和铁水平分析表明，与对照相比，NA几乎增加了一倍，而铁浓度没有变化。鹰嘴豆种子中NA含量的增加可能会转化为铁生物有效性的提高，从而可能克服豆类中发现的生物有效性抑制剂的影响；然而，需要进一步研究来证实这一点。这是已知的第一个基因工程铁生物强化鹰嘴豆的例子；从本研究中收集的信息可用于未来的豆类生物强化工作，以帮助缓解全球缺铁问题。
