Rhodococcus qingshengii facilitates the phytoextraction of Zn, Cd, Ni, and Pb from soils by Sedum alfredii Hance
Rhodococcus qingshengii facilitates the phytoextraction of Zn, Cd, Ni, and Pb from soils by Sedum alfredii Hance
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DOI：
10.1016/j.jhazmat.2021.127638
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发表时间：
2021-12-09
影响因子：
13.6
通讯作者：
Li, Jiaxin
中科院分区：
文献类型：
--
作者：
Du, Shaoting;Lu, Qi;Li, Jiaxin
通过植物生长促进微生物提高超积累植物对重金属的植物提取效率，已被认为是从污染土壤中去除重金属的有效策略。然而，通过根际细菌分解超积累植物中的脱落酸(ABA)是否能促进HM植物的提取还不清楚。在本研究中，超积累植物东南景天接种了ABA分解代谢细菌青神红球菌，在受污染的水稻植株中，锌、镉、镍和铅的含量分别比对照无菌植株增加了35%、63%、49%和49%，而在矿质土壤中生长的植株中，锌、镉、镍和铅的含量分别增加了112%、105%、46%和49%。然而，这些植物之间的铜含量并没有明显的变化。此外，指示植物修复潜力的参数，包括转移因子(Tf)和生物浓缩因子(BCF)，表明接种细菌可以显著提高土壤中锌、镉、镍和铅的植物提取效率。值得注意的是，青海根结线虫对土壤中HMS的生物有效性没有影响，但与这些HMS的吸收相关的转运蛋白SaIRT1、SaZIP1、SaZIP2、SaZIP3、SaNramp1、SaNramp3、SaNramp6、SaHMA2和SaHMA3的表达被上调。这些结果表明，接种青海红曲霉可以通过分解ABA来提高植物对HM的吸收能力，这可能为提高HM污染土壤的植物修复效果提供了一种有前途的策略。
The enhanced heavy metal (HM) phytoextraction efficiency of hyperaccumulating plants via plant-growthpromoting microbes has been proposed as an effective strategy to remove HMs from contaminated soil. Nevertheless, it remains unclear whether catabolizing the abscisic acid (ABA) in hyperaccumulating plants via rhizobacteria can facilitate HM phytoextraction. In the present study, a hyperaccumulator, Sedum alfredii Hance, inoculated with an ABA-catabolizing bacterium Rhodococcus qingshengii, showed higher concentrations of Zn, Cd, Ni, and Pb in the contaminated paddy-grown plant shoots by 35%, 63%, 49%, and 49%, and in plants grown in mine soils by 112%, 105%, 46%, and 49%, respectively, than in the controlbacteria-free plants. However, no significant changes were observed in Cu content between these plants. Furthermore, parameters indicating phytoremediation potential, including the translocation factor (TF) and bioconcentration factor (BCF), revealed that bacterial inoculation could markedly increase the efficacy of Zn, Cd, Ni, and Pb phytoextraction from the soil. Notably, the bioavailabilities of HMs in soils were not influenced by R. qingshengii; however, the expression of transporters related to the uptake of these HMs, including SaIRT1, SaZIP1, SaZIP2, SaZIP3, SaNramp1, SaNramp3, SaNramp6, SaHMA2, and SaHMA3, was upregulated. These findings indicate that R. qingshengii inoculation could increase the HM-uptake ability of plants by catabolizing ABA and may provide a promising strategy for enhancing the phytoremediation efficacy in HM-contaminated soils.