Cadmium translocation and accumulation in developing barley grains
Cadmium translocation and accumulation in developing barley grains
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DOI：
10.1007/s00425-007-0610-3
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发表时间：
2007-12-01
期刊：
影响因子：
4.3
通讯作者：
Wei, Kang
中科院分区：
文献类型：
--
作者：
Chen, Fei;Wu, Feibo;Wei, Kang
土壤镉污染已成为世界范围内危害农业和环境的一个重要因素，严重影响了食品安全生产。以二棱大麦cv. ZAU 3在含有韧皮部（铷）和木质部（锶）运输标记的镉胁迫营养液中培养。离体幼穗各部位Cd含量随外源Cd浓度的增加而增加，0.5，2，8 M Cd处理15 d后各器官Cd含量依次为：芒>茎>谷粒>轴>颖片，Cd主要积累在籽粒中，占离体穗5个部位Cd总量的51.0%。与茎、芒、轴和颖片相比，籽粒中Cd积累量不仅随外源Cd水平的增加而增加，而且随暴露时间的延长而增加。离体穗4个部位Cd积累量在第5天呈上升趋势，第10天急剧下降，12.5天后又开始上升。去芒和环剥处理显著降低了籽粒中Cd含量，在中等和较高相对湿度条件下添加蔗糖或锌也能诱导籽粒中Cd含量降低。Cd运输到发育中的谷物的急剧减少。结果表明，芒、轴和颖可能参与了镉向发育中籽粒的转运，并表明成熟谷物中镉的再分配是影响收获籽粒品质的重要生理过程。结果表明，提高相对湿度至90%，并在灌浆期添加Zn，有利于降低Cd在籽粒中的积累。
Soil cadmium (Cd) contamination has posed a serious problem for safe food production and become a potential agricultural and environmental hazard worldwide. In order to study the transport of Cd into the developing grains, detached ears of two-rowed barley cv. ZAU 3 were cultured in Cd stressed nutrient solution containing the markers for phloem (rubidium) and xylem (strontium) transport. Cd concentration in each part of detached spikes increased with external Cd levels, and Cd concentration in various organs over the three Cd levels of 0.5, 2, 8 M Cd on. 15-day Cd exposure was in the order: awn > stem > grain > rachis > glume, while the majority of Cd was accumulated in grains with the proportion of 51.0% relative to the total Cd amount in the five parts of detached spikes. Cd accumulation in grains increased not only with external Cd levels but the time of exposure contrast to stem, awn, rachis and glume. Those four parts of detached spike showed increase Cd accumulation for 5 days, followed by sharp decrease till day 10 and increase again after 12.5 days. Awn-removal and stem-girdling markedly decreased Cd concentration in grains, and sucrose or zinc (Zn) addition to the medium and higher relative humidity (RH) also induced. dramatic reduction in Cd transport to developing grains. The results indicated that awn, rachis and glume may involve in Cd transport into developing grains, and suggested that Cd redistribution in maturing cereals be considered as an important physiological process influencing the quality of harvested grains. Our results suggested that increasing RH to 90% and Zn addition in the medium at grain filling stage would be beneficial to decrease Cd accumulation in grains.