Universidade Federal do Espírito Santo, Centro de Ciências Humanas e Naturais, Departamento de Ciências Biológicas, 29075-910 Vitória, Espírito Santo, Brazil.
Universidade Federal de São Carlos, Centro de Ciências Biológicas e da Saúde, Departamento de Ciências Fisiológicas, 13565-905 São Carlos, São Paulo, Brazil.
Chemosphere. 2015 May;127:27-34. doi: 10.1016/j.chemosphere.2015.01.011. Epub 2015 Feb 2.
In Brazil, some mangrove areas are subjected to air pollution by particulate iron from mining activities. However, the effect of this pollutant on mangrove plants is not well known. This study aimed to comparatively analyze the morphoanatomy, histochemistry, and iron accumulation in leaves of Avicennia schaueriana, Laguncularia racemosa, and Rhizophora mangle. Samples were collected from five mangrove sites of Espírito Santo state, each of which is exposed to different levels of particulate iron pollution. The amount of particulate material settled on the leaf surface was greater in A. schaueriana and L. racemosa, which contain salt glands. High iron concentrations were found in leaves of this species, collected from mangrove areas with high particulate iron pollution, which suggests the foliar absorption of this element. None of the samples from any of the sites showed morphological or structural damage on the leaves. Scanning electron microscopy (SEM) coupled to X-ray diffraction rendered a good method for evaluating iron on leaves surfaces. A histochemical test using Prussian blue showed to be an appropriate method to detect iron in plant tissue, however, proved to be an unsuitable method for the assessment of the iron bioaccumulation in leaves of A. schaueriana and R. mangle. So far, this study demonstrates the need of evaluating the pathway used by plants exposed to contaminated particulate matter to uptake atmospheric pollutants.
在巴西，一些红树林地区受到采矿活动产生的颗粒态铁污染。然而，这种污染物对红树林植物的影响尚不清楚。本研究旨在比较分析受不同程度颗粒态铁污染的巴西五个红树林地点的白骨壤、卤蕨和红海榄叶片的形态解剖学、组织化学和铁积累。从含有盐腺的白骨壤和卤蕨叶片表面收集到的颗粒物质的量较多。从高颗粒态铁污染的红树林地区采集到的这两种植物的叶片中发现了高浓度的铁，这表明这些元素是通过叶片吸收的。来自任何地点的样本都没有显示出叶片上的形态或结构损伤。扫描电子显微镜 (SEM) 与 X 射线衍射的结合为评估叶片表面的铁提供了一种很好的方法。使用普鲁士蓝的组织化学测试被证明是一种检测植物组织中铁的合适方法，但对于评估白骨壤和红海榄叶片中铁的生物积累来说，这是一种不合适的方法。到目前为止，这项研究表明需要评估暴露于污染颗粒物质的植物吸收大气污染物的途径。
