NIAB, 93 Lawrence Weaver Road, CB3 0LE, Cambridge, UK.
Robert W. Holley Center for Agriculture and Health, USDA-ARS, 14853, Ithaca, NY, USA.
BMC Plant Biol. 2021 May 11;21(1):212. doi: 10.1186/s12870-021-02996-6.
Anemia is thought to affect up to 1.6 billion people worldwide. One of the major contributors to low iron (Fe) absorption is a higher proportion of cereals compared to meats and pulse crops in people's diets. This has now become a problem in both the developed and developing world, as a result of both modern food choice and food availability. Bread wheat accounts for 20 % of the calories consumed by humans and is an important source of protein, vitamins and minerals meaning it could be a major vehicle for bringing more bioavailable Fe into the diet.
To investigate whether breeding for higher concentrations of Fe in wheat grains could help increase Fe absorption, a multiparent advanced generation intercross (MAGIC) population, encompassing more than 80 % of UK wheat polymorphism, was grown over two seasons in the UK. The population was phenotyped for both Fe concentration and Fe bioavailability using an established Caco-2 cell bioassay. It was found that increasing Fe concentrations in the grains was not correlated with higher Fe bioavailability and that the underlying genetic regions controlling grain Fe concentrations do not co-localise with increased Fe absorption. Furthermore, we show that phytate concentrations do not correlate with Fe bioavailability in our wheat population and thus phytate-binding is insufficient to explain the lack of correlation between Fe bioavailability and Fe concentrations in the wheat grain. Finally, we observed no (Fe bioavailability) or low (Fe concentration) correlation between years for these traits, confirming that both are under strong environmental influence.
This suggests that breeders will have to select not only for Fe concentrations directly in grains, but also increased bioavailability. However the use of numerous controls and replicated trials limits the practicality of adoption of screening by Caco-2 cells by many breeders.
据认为，贫血影响全球多达 16 亿人。人们饮食中谷物相对于肉类和豆类的比例较高，是导致铁（Fe）吸收量低的主要原因之一。由于现代食物选择和食物供应，这在发达国家和发展中国家都已成为一个问题。面包小麦占人类消耗卡路里的 20%，是蛋白质、维生素和矿物质的重要来源，这意味着它可以成为将更多生物可利用铁纳入饮食的主要载体。
为了研究在小麦籽粒中培育更高浓度的 Fe 是否有助于增加 Fe 吸收，在英国两个季节种植了一个包含超过 80%英国小麦多态性的多亲本高级世代互交（MAGIC）群体。该群体使用已建立的 Caco-2 细胞生物测定法对 Fe 浓度和 Fe 生物利用度进行表型分析。结果发现，增加籽粒中的 Fe 浓度与更高的 Fe 生物利用度无关，控制籽粒 Fe 浓度的潜在遗传区域与增加的 Fe 吸收没有共定位。此外，我们表明植酸盐浓度与我们小麦群体中的 Fe 生物利用度不相关，因此植酸盐结合不足以解释小麦籽粒中 Fe 生物利用度与 Fe 浓度之间缺乏相关性。最后，我们观察到这些性状在不同年份之间没有（Fe 生物利用度）或低（Fe 浓度）相关性，证实它们都受到强烈的环境影响。
这表明，培育者不仅要选择籽粒中直接的 Fe 浓度，还要选择增加生物利用度。然而，由于使用了大量对照和重复试验，限制了许多培育者采用 Caco-2 细胞筛选的实用性。
