The University of Queensland, School of Agriculture and Food Sciences, Gatton, Queensland, Australia.
Department of Agriculture and Fisheries Gatton, Queensland, Australia.
Ann Bot. 2019 Feb 15;123(3):543-556. doi: 10.1093/aob/mcy189.
Understanding the spatial distribution of inorganic nutrients within edible parts of plant products helps biofortification efforts to identify and focus on specific uptake pathways and storage mechanisms.
Kernels of sweetcorn (Zea mays) variety 'High zeaxanthin 103146' and maize inbred line 'Thai Floury 2' were harvested at two different maturity stages, and the distributions of K, P, S, Ca, Zn, Fe and Mn were examined in situ using synchrotron-based X-ray fluorescence microscopy.
The distribution of inorganic nutrients was largely similar between maize and sweetcorn, but differed markedly depending upon the maturity stage after further embryonic development. The micronutrients Zn, Fe and Mn accumulated primarily in the scutellum of the embryo during early kernel development, while trace amounts of these were found in the aleurone layer at the mature stage. Although P accumulated in the scutellum, there was no direct relationship between the concentrations of P and those of the micronutrients, compared with the linear trend between Zn and Fe concentrations.
This study highlights the important role of the embryo as a micronutrient reserve for sweetcorn and maize kernels, and the need to understand how biofortification efforts can further increase the inorganic nutrient concentration of the embryo for human consumption.
了解植物产品可食用部分中无机养分的空间分布有助于生物强化工作，以确定并专注于特定的吸收途径和储存机制。
在两个不同的成熟阶段收获甜玉米（Zea mays）品种“高玉米黄质 103146”和玉米自交系“泰国粉质 2”的玉米粒，并使用基于同步加速器的 X 射线荧光显微镜原位检查 K、P、S、Ca、Zn、Fe 和 Mn 的分布。
无机养分的分布在玉米和甜玉米之间基本相似，但在胚胎进一步发育后的成熟阶段，差异显著。微量元素 Zn、Fe 和 Mn 主要在早期籽粒发育过程中积累在胚的盾片中，而在成熟阶段的糊粉层中则发现痕量的这些元素。尽管 P 积累在盾片中，但与 Zn 和 Fe 浓度之间的线性趋势相比，P 浓度与微量元素浓度之间没有直接关系。
本研究强调了胚胎作为甜玉米和玉米籽粒中微量营养素储备的重要作用，以及需要了解生物强化工作如何进一步提高胚胎的无机养分浓度以供人类食用。
