| 杨昳,张羽,尹秋霞,李明堂.多功能复合菌对玉米幼苗镍和镉胁迫的解毒特征及其机理[J].农业环境科学学报,2022,41(11):2448-2457. |
| 多功能复合菌对玉米幼苗镍和镉胁迫的解毒特征及其机理 |
| Detoxification characteristics and mechanism of nickel and cadmium stress in maize seedlings by multifunctional bacterial consortia |
| 投稿时间：2022-05-01 |
| DOI：10.11654/jaes.2022-0439 |
| 中文关键词: 沙福芽孢杆菌 睾丸酮丛毛单胞菌 镍 镉 玉米幼苗 解毒机理 |
| 英文关键词: Bacillus safensis Comamonas testosteroni nickel cadmium maize seedling detoxification mechanism |
| 基金项目:国家自然科学基金项目（42077137）；吉林省重点研发计划项目（20200403003SF） |
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| 摘要点击次数: 753 |
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| 中文摘要: |
| 微生物可通过与植物的共生作用来降低重金属对植物的毒性，在重金属污染土壤低碳和绿色修复方面具有重要的应用价值。通过水培实验研究了沙福芽孢杆菌N4和睾丸酮丛毛单胞菌ZG2复合菌对玉米幼苗镍（Ni）和镉（Cd）胁迫的解毒特征及其机制。结果表明，在Ni和Cd胁迫浓度为5~20 mg·L-1的水培条件下，玉米种子萌发和幼苗生长都受到了明显的影响，而复合菌可通过与玉米幼苗的共生作用进行生长繁殖，降低了Ni和Cd对玉米幼苗生长的毒害作用，进而提高了玉米幼苗的株高、主根长、生物量以及叶绿素SPAD值。在Ni和Cd的胁迫浓度均为5、10、20 mg·L-1的条件下，与对照相比，复合菌可使玉米幼苗茎叶部Ni含量分别降低42.2%、37.0%、35.1%，Cd含量分别降低25.8%、27.2%、28.4%，叶片内较高毒性形态（乙醇提取态和去离子水提取态） Ni的分布比例之和降低13.9%~21.5%，Cd的分布比例之和降低14.7%~20.3%，叶片细胞器中Ni的分布比例降低12.1%~17.0%，Cd的分布比例降低20.7%~29.3%，使Ni胁迫下玉米幼苗茎叶部的Mg含量分别增加21.0%、39.0%、24.1%，Cd胁迫下玉米幼苗茎叶部的Mg含量分别增加29.4%、11.4%、35.9%，并且随着Mg浓度的增加，叶片Ni和Cd的含量进一步降低。研究表明复合菌通过降低玉米幼苗对Ni和Cd的吸收，促进叶片中Ni和Cd向较低毒性形态转化，降低叶片细胞器中Ni和Cd的占比，提高玉米幼苗对Mg的吸收等机制降低Ni和Cd对玉米幼苗的毒性作用，复合菌在Ni和Cd污染玉米耕地土壤修复方面具有重要的应用潜力。 |
| 英文摘要: |
| Microorganisms may reduce the toxicity of heavy metals through symbiosis with plants, which show important application value in low-carbon and green remediation of soil contaminated with heavy metals. In this study, the detoxification characteristics and mechanisms of Bacillus safensis N4 and Comamonas testosteroni ZG2 bacterial consortia against nickel (Ni) and cadmium (Cd) stress in maize seedlings were investigated using hydroponic experiments. The results showed that maize seed germination and seedling growth were significantly affected by Ni and Cd stress at the concentrations of 5-20 mg·L-1 under hydroponic conditions. However, the bacterial consortia grew and multiplied through symbiotic interactions with the maize seedlings, thus reducing the toxic effects of Ni and Cd on the growth of the seedlings, which in turn increased the plant height, primary root length, biomass, and chlorophyll SPAD values of the seedlings. Under conditions of Ni and Cd stress at concentrations of 5, 10 mg·L-1, and 20 mg·L-1, the Ni content in aboveground maize seedlings decreased by 42.2%, 37.0%, and 35.1%, respectively, and the Cd content decreased by 25.8%, 27.2%, and 28.4% respectively, compared with the content in control seedlings. The sum of the distribution proportion of more toxic forms of Ni in leaves decreased by 13.9%-21.5%, and the sum of the distribution proportion of Cd decreased by 14.7%-20.3%. The distribution proportions of Ni in leaf organelles decreased by 12.1%-17.0%, and the distribution proportions of Cd decreased by 20.7%-29.3%. Under Ni stress at concentrations of 5, 10 mg·L-1, and 20 mg·L-1, the aboveground Mg content of maize seedlings increased by 21.0%, 39.0%, and 24.1%, respectively, whereas under Cd stress at these concentrations, the aboveground Mg content of maize seedlings increased by 29.4%, 11.4%, and 35.9%, respectively. The leaf Ni and Cd content further decreased with increasing Mg concentration. These results indicate that the bacterial consortia reduce the toxic effects of Ni and Cd on maize seedlings by reducing their absorption, promoting their transformation in leaves to less toxic forms, reducing their proportions in leaf organelles, and improving the absorption of Mg in maize seedlings. |
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