Uptake and Translocation of Cadmium and Its Physiological Effects in Two Rice Cultivars Differed in Grain Cadmium Concentration

doi:10.3969/j.issn.1001-7216.2011.03.010

Abstract

Abstract: A hydroponic experiment and a pot experiment were conducted to investigate Cd uptake and translocation in rice and their physiological effects at several growth stages by using two rice cultivars with different grain Cd concentrations. In the pot experiment, the grain Cd contents of low Cd rice cultivar(A16) and high Cd cultivar(A54) were 0.31 mg/kg and 0.88 mg/kg, respectively at a total soil Cd concentration of 1.57 mg/kg. Both hydroponic and pot experiments showed that A16 absorbed and translocated more Cd than A54 at the seedling stage. However, after the seedling stage, the amounts of Cd uptake and translocation by A54 were higher than those of A16. By comparing Cd accumulation in two rice cultivars at various growth stages, the highest increase in Cd accumulation was observed at seedlingelongation stage. The amount of nonprotein thiol(NPT) was not only closely related to Cd stress, but also partly controlled Cd translocation from roots to shoots, thus affecting the Cd concentration in rice grain. According to Cd and NPT contents in shoots and roots of the two rice cultivars at each growth stage, it may be speculated that the variation of grain Cd concentration was largely controlled by root uptake and translocation to shoot. Root Cd sequestration and rhizosphere soil properties may result in the differences in rice Cd absorption and translocation between the seedling stage and other stages.

Key words: rice, Cd, uptake, translocation, malonaldehyde, non-protein thiol

摘要： 以籽粒镉(Cd)含量不同的两个水稻品种为材料，采用水培和盆栽试验，研究了水稻不同生育期Cd吸收转运、生理效应对籽粒Cd浓度的影响。盆栽试验结果表明，在Cd含量为1.57 mg/kg的土壤中，中香1号（A16，低Cd品种）和IR656103824263（A54，高Cd品种）糙米中Cd含量分别为0.88和0.31 mg/kg。水培和土培试验均显示品种A16对Cd的吸收转运在苗期强于A54，但在苗期之后，A54吸收转运Cd的强度高于A16。比较不同生育期两个品种单株Cd累积量，发现苗期至拔节期的增幅最大。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。从各生育期A16和A54地上部和根中的Cd和NPT含量可以推断，水稻籽粒Cd含量的差异很大程度上受到根部吸收和向地上部转运的制约。水稻苗期和其他生育期Cd吸收转运特点不同的原因可能包括根系Cd滞留能力及根际土壤性状的差异。

关键词: 水稻, 镉, 吸收, 转运, 丙二醛, 非蛋白巯基

LI Peng,GE Ying,WU Long-hua,SHEN Li-bo,TAN Wei-na,LUO Yong-ming. Uptake and Translocation of Cadmium and Its Physiological Effects in Two Rice Cultivars Differed in Grain Cadmium Concentration[J]. Chinese Journal of Rice Science, DOI: 10.3969/j.issn.1001-7216.2011.03.010 .

李鹏, ,葛滢,吴龙华,沈丽波,谭维娜,骆永明. 两种籽粒镉含量不同水稻的镉吸收转运及其生理效应差异初探
[J]. 中国水稻科学, DOI: 10.3969/j.issn.1001-7216.2011.03.010 .

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