Analysis of Metal Element Distributions in Rice (Oryza sativa L.) Seeds and Relocation during Germination Based on X-Ray Fluorescence Imaging of Zn, Fe, K, Ca, and Mn

Abstract

Knowledge of mineral localization within rice grains is important for understanding the role of different elements in seed development, as well as for facilitating biofortification of seed micronutrients in order to enhance seeds’ values in human diets. In this study, the concentrations of minerals in whole rice grains, hulls, brown rice, bran and polished rice were quantified by inductively coupled plasma mass spectroscopy. The in vivo mineral distribution patterns in rice grains and shifts in those distribution patterns during progressive stages of germination were analyzed by synchrotron X-ray microfluorescence. The results showed that half of the total Zn, two thirds of the total Fe, and most of the total K, Ca and Mn were removed by the milling process if the hull and bran were thoroughly polished. Concentrations of all elements were high in the embryo regions even though the local distributions within the embryo varied between elements. Mobilization of the minerals from specific seed locations during germination was also element-specific. High mobilization of K and Ca from grains to growing roots and leaf primordia was observed; the flux of Zn to these expanding tissues was somewhat less than that of K and Ca; the mobilization of Mn or Fe was relatively low, at least during the first few days of germination.

Quantifying Micronutrient (Zn and Fe) Content in Super Elite Accession at Varying Level of Polishing by Using X-Ray Fluorescence in Rice Grain Grown under Aerobic Condition

“…Attempt was made to understand the reason of loss from brown to white rice and the possible reason found was that polishing of brown rice causes leaching of nutrient and leads to decrease in content of Fe and Zn. The order of high Fe and Zn includes bran (embryo + aleurone layer) > hull > whole grain > brown rice > polished rice (endosperm) as per studies conducted by Lu et al, (2013) and similar result were obtained from this studies. The content of iron and zinc for both brown and white rice are experimentally comparable with the work done earlier by Jorhem et al, (2008).…”

Silicon induced Fe deficiency affects Fe, Mn, Cu and Zn distribution in rice (Oryza sativa L.) growth in calcareous conditions

“…Furthermore, if energy-dispersive X-90 ray analysis (EDX or EDAX) is used, the Fe distribution in the tissue could be 91 described. The large majority of the available information related to the localization of 92 Fe, Mn, Cu, Zn and Si in rice is focused on rice seeds using S-XRF (Lu et al, 2013). Moore et al, 2011).…”

Micro-PIXE mapping of mineral distribution in mature grain of two pearl millet cultivars

“…To support this drive for biofortification, there is a need to understand the spatial distribution of minerals in different tissues within the grain. The mapping of minerals in seed tissues has been achieved in several notable studies, which include work on important cereals, such as wheat [8,9], barley [10] and rice [11,12]; as well as certain pseudocereals [13][14][15] and legumes [16,17]. To our knowledge, the only studies reporting on the spatial distribution of mineral elements in millet, include a recent study using micro-proton-induced Xray emission (micro-PIXE) for finger millet [18] and a much earlier study on pearl millet, using energy dispersive X-ray analysis (EDX) [19].…”