Djedidi Salem, Kojima Katsuhiro, Yamaya Hiroko, Ohkama-Ohtsu Naoko, Bellingrath-Kimura Sonoko Dorothea, Watanabe Izumi, Yokoyama Tadashi
Department of Biological Production Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-chou, Fuchu, Tokyo, 183-8509, Japan.
J Plant Res. 2014 Sep;127(5):585-97. doi: 10.1007/s10265-014-0647-x. Epub 2014 Jul 8.
The effects of inoculation with Bacillus and Azospirillum strains on growth and cesium accumulation of five plant species, Komatsuna, Amaranth, sorghum, common millet and buckwheat, grown on cesium-spiked soil were assessed for potential use in cesium remediation. Pot experiments were performed using "artificially" Cs-contaminated soil. Three treatments were applied based on Cs location in the soil. For a soil height of 15 cm in the pots, Cs was added as follows: in the top five cm to imitate no ploughing condition; in the bottom five cm simulating inverted ploughing; and uniformly distributed Cs reproducing normal plowing. Generally, inoculation of Cs-exposed plants significantly enhanced growth and tolerance to this element. Transfer factor (ratio of Cs concentration in the plant tissues to that in surrounding soil) was strongly influenced by Cs distribution, with higher values in the top-Cs treatment. Within this treatment, inoculation of Komatsuna with Bacillus and Azospirillum strains resulted in the greatest transfer factors of 6.55 and 6.68, respectively. Cesium content in the shoots was high in the Azospirillum-inoculated Komatsuna, Amaranth, and buckwheat, i.e., 1,830, 1,220, and 1,030 µg per pot, respectively (five plants were grown in each pot). Therefore, inoculation of Komatsuna and Amaranth with the strains tested here could be effective in enhancing Cs accumulation. The decrease of Cs transfer under uniform- and bottom-Cs treatments would suggest that countermeasures aiming at decreasing the transfer of Cs could rely on ploughing practices.
评估了接种芽孢杆菌属和固氮螺菌属菌株对在添加铯土壤上生长的小松菜、苋菜、高粱、黍和荞麦这五种植物的生长及铯积累的影响，以探讨其在铯修复中的潜在用途。使用“人工”受铯污染的土壤进行盆栽试验。根据铯在土壤中的位置设置了三种处理方式。对于盆栽中15厘米高的土壤，铯添加方式如下：添加到顶部5厘米以模拟未翻耕条件；添加到底部5厘米以模拟翻耕；以及均匀分布铯以模拟正常翻耕。一般来说，对接种铯的植物进行接种显著促进了生长并增强了对该元素的耐受性。转移因子（植物组织中铯浓度与周围土壤中铯浓度之比）受铯分布的强烈影响，在顶部添加铯的处理中值更高。在该处理中，用芽孢杆菌属和固氮螺菌属菌株接种小松菜分别产生了最大转移因子，为6.55和6.68。接种固氮螺菌属的小松菜、苋菜和荞麦地上部分的铯含量较高，即每盆分别为1830、1220和1030微克（每盆种植五株植物）。因此，用本文测试的菌株接种小松菜和苋菜可能有效地增强铯积累。在均匀添加铯和底部添加铯处理下铯转移的减少表明，旨在减少铯转移的对策可能依赖于翻耕措施。
