Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, Mawson Lakes, South Australia, SA-5095 Australia.
J Exp Bot. 2011 Jan;62(1):273-82. doi: 10.1093/jxb/erq270. Epub 2010 Sep 5.
Understanding the accumulation and distribution of essential nutrients in cereals is of primary importance for improving the nutritional quality of this staple food. While recent studies have improved the understanding of micronutrient loading into the barley grain, a detailed characterization of the distribution of micronutrients within the grain is still lacking. High-definition synchrotron X-ray fluorescence was used to investigate the distribution and association of essential elements in barley grain at the micro scale. Micronutrient distribution within the scutellum and the embryo was shown to be highly variable between elements in relation to various morphological features. In the rest of the grain, the distribution of some elements such as Cu and Zn was not limited to the aleurone layer but extended into the endosperm. This pattern of distribution was less marked in the case of Fe and, in particular, Mn. A significant difference in element distribution was also found between the ventral and dorsal part of the grains. The correlation between the elements was not consistent between and within tissues, indicating that the transport and storage of elements is highly regulated. The complexity of the spatial distribution and associations has important implications for improving the nutritional content of cereal crops such as barley.
了解谷物中必需营养元素的积累和分布对于提高这种主食的营养价值至关重要。虽然最近的研究提高了对微量元素加载到大麦籽粒中的理解，但对微量元素在籽粒内的分布的详细描述仍然缺乏。高清晰度同步加速器 X 射线荧光用于在微观尺度上研究大麦籽粒中必需元素的分布和关联性。微量元素在盾片和胚中的分布在不同形态特征下，各元素之间差异很大。在谷物的其余部分，一些元素（如 Cu 和 Zn）的分布并不局限于糊粉层，而是延伸到胚乳中。Fe 的分布模式不那么明显，尤其是 Mn。元素分布在籽粒的腹面和背面之间也存在显著差异。元素之间的相关性在组织之间和组织内并不一致，表明元素的运输和储存受到高度调节。这种空间分布和关联性的复杂性对提高大麦等谷类作物的营养价值具有重要意义。
