土壤汞污染对水稻的生长、 发育以及稻米的品质均产生重要影响, 目前, 应用红外光谱研究汞对水稻植株中有机物分子结构的影响尚不深入。 采取大田低、 中、 高三种汞污染水平下的水稻植株样品, 应用傅里叶变换-红外光谱法(FTIR)测定水稻根、 茎叶、 籽粒三个器官的特征吸收峰, 研究不同程度土壤汞污染对植株傅里叶红外光谱特征的影响。 结果表明: 土壤汞污染导致了汞在水稻植株中的累积, 其含量分布为: 根>茎叶>籽粒。 水稻根、 茎叶在3 428, 2 922, 2 851, 2 364, 2 344, 1 750~1 500和1 150~935 cm-1等波数均受汞污染的影响, 而汞污染下的水稻籽粒仅在3 426, 2 361, 2 335和1 750~1 300 cm-1波数发生了变化。 综合分析水稻植株各器官的FTIR光谱特征, 可能说明: 汞胁迫降低了水稻根、 茎叶和籽粒中碳水化合物, 刺激了根中羧酸、 半乳糖、 饱和脂类和茎叶中多种多糖的生成。 水稻根和茎叶是阻抑汞迁移与侵害的主要器官。 根部似乎是在茎叶加强多糖类物质的生成并向根部转运营养物质的基础上通过分泌有机酸和增强细胞壁、 膜的形成, 使其与Hg螯合和吸附, 阻止汞向根内的迁移来实现抗汞胁迫的。 可以通过加强根与茎叶的抗汞过程来降低汞对水稻尤其是稻米的侵害。 在种植管理中不仅要重视汞在稻米中的积累, 还应当重视汞对水稻生长发育和稻米品质的影响。

Soilmercury (Hg) contamination may affect the growth of rice plant and rice quality. However, little information has been available so far on the effect of Hg pollution on the molecular structure of nutrientcomponents in rice by Fourier transform-infrared spectroscopy(FT-IR). This study aimed to detect the effect of soil Hg pollution on the FT-IRcharacteristics of rice plant organs through a FT-IR scanning of riceroot, stalkplus leaf, and seed collected from rice field under low-, medium-, high-Hg contamination. Results showed that soil Hg resulted in an accumulation in rice organs with an Hg allocation: root >stalk plus leaf>seed. FT-IR signals of root and stalk plus leaf at 3 428, 2 922, 2 851, 2 364, 2 344, 1 750～1 500, 1 150～935 cm-1 were under influence of Hg stress. Meanwhile, FT-IR spectra of rice seed seemed to be affected by Hg pollution at 3 426, 2 361, 2 335 and 1 750～1 300 cm-1. FT-IR analysis may indicate that Hg stress reduced absorbance of carbohydrate in all rice organs and stimulated the production of carboxylic acids, galactosum, and saturated lipids in root and the synthesis of polysaccharides in stalk and leaf. Root, stalk and leaf were the main organs to resist Hg stress for rice plant. Root may secrete organic acids to chelate Hg and enhance the formation of cytoderm to adsorb Hg, which may withhold Hg transportation from root surface to rice plant. It is supposed that an appropriate utilization of such mechanism of Hg resistance may reduce the harm to rice plant. Attention should be paid not only on the content accumulation of Hg in rice but also the effect of Hg contamination on rice growth and rice quality.