Cadmium (Cd) is known as one of the five most toxic environment pollutants. It can be absorbed readily by crops and accumulated in human body through food chains, resulting in human body health problems. The accumulation of Cd in rice grains is a major agricultural problem in regions with Cd pollution. It is important to clarify the mechanism of Cd accumulation reduction in different cultivar rice on contaminated soil with cadmium. The experiment were conducted to investigate the uptake and translocation of cadmium and the contents of NPT (total non-protein thiol), GSH and other non-protein thiol [PC (phytochelatin)] in roots and leaves of four rice varieties with different grain Cd content under Cd stress. The results showed that the tested rice varieties grown in the soil polluted by cadmium, the contents of four varieties of grain rice were much higher than National secondary standard. The content of Cd was root>shoot>grain. The content of cadmium in indica rice grain was higher than that of japonica rice grain. The absorption and transportation of cadmium of four kinds of rice had the significant difference. The transfer factor of Cd with higher Cd concentration of grain was higher than that of low Cd rice cultivar. The content of NPT in root and shoot of Xiushui09 was higher than that of Xuda o5, but the content of NPT in leaves of Xiushui 09 was lower than that of Xuda o5. The content of higher cadmium in the root of Fengliangyou 1 was with higher NPT content, but the content of NPT in leaves was lower than that of Liangyou 6206. The content of GSH of japonica and indica rice grain with higher Cd was higher than rice grain with lower Cd in root, shoot and leave. The content of PC in Xiushui 09 with higher cadmium content was significantly higher than that with lower grain content. There was no significant difference in PC content between two rice varieties with different cadmium content in indica rice grain. The results show that the detoxification process of different rice varieties is different under cadmium stress, and the content of nonprotein is sensitive to cadmium pollution.%镉(Cd)被列为环境污染物中最危险的5种物质之一.镉极易被作物吸收并通过食物链在人体内积累导致人体健康受到威胁.镉污染地区稻米镉积累是亟待解决的重要农业问题.分析镉污染土壤上种植的不同水稻品种对镉的耐受性具有重要意义.采用盆栽试验方法,研究了种植于镉污染土壤(Cd全量2.36 mg·kg-1)上的不同水稻(Oryza sativa)品种(两种粳稻和两种籼稻)镉积累情况及根、茎、叶中非蛋白巯基物质含量.研究结果表明,在镉污染土壤条件下,4种水稻籽粒镉含量明显高于国家二级标准(水稻籽粒镉含量0.2 mg·kg-1),且表现为根部>茎叶>籽粒.籼稻籽粒镉含量大于粳稻籽粒镉含量;4种水稻的镉转移系数不同,不同水稻品种对镉的吸收和运转具有显著差异,籽粒镉含量高的水稻品种镉的转移系数高于籽粒镉含量低的水稻品种.水稻非蛋白巯基(NPT)含量不仅与Cd胁迫程度密切相关,也在一定程度上制约着Cd从根部向地上部的转运,从而对水稻籽粒Cd含量产生影响.粳稻籽粒镉含量高的秀水09根茎中NPT含量较徐稻5号高,但秀水09叶中NPT含量低于徐稻5号,籼稻籽粒镉含量高的丰两优1号根茎中NPT含量也较高,但叶中NPT含量低于两优6206.粳稻与籼稻籽粒镉含量高的水稻品种根茎叶中GSH含量高于籽粒含量低的水稻品种;粳稻籽粒镉含量高的秀水09根中PC含量明显高于籽粒含量低的徐稻5号,籼稻籽粒镉含量不同的两种水稻根中PC含量无明显差异.研究表明,不同水稻品种在镉胁迫下的解毒过程不同,巯基物质含量对水稻镉污染较敏感.
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