College of Resources, Sichuan Agricultural University, Chengdu, Sichuan, China.
Sichuan Provincial Academy of Natural Resource and Sciences, Chengdu, Sichuan, China.
PeerJ. 2022 Apr 21;10:e13215. doi: 10.7717/peerj.13215. eCollection 2022.
Mine soil is not only barren but also contaminated by some heavy metals. It is unclear whether some rhizobia survived under extreme conditions in the nickel mine soil. Therefore, this study tries to isolate some effective soybean plant growth promoting and heavy metal resistant rhizobia from nickel mine soil, and to analyze their diversity. Soybean plants were used to trap rhizobia from the nickel mine soil. A total of 21 isolates were preliminarily identified as rhizobia, which were clustered into eight groups at 87% similarity level using BOXA1R-PCR fingerprinting technique. Four out of the eight representative isolates formed nodules on soybean roots with effectively symbiotic nitrogen-fixing and plant growth promoting abilities in the soybean pot experiment. Phylogenetic analysis of 16S rRNA, four housekeeping genes (---) and genes assigned the symbiotic isolates YN5, YN8 and YN10 into and YN11 into , respectively. They also showed different tolerance levels to the heavy metals including cadmium, chromium, copper, nickel, and zinc. It was concluded that there were some plant growth promoting and heavy metal resistant rhizobia with the potential to facilitate phytoremediation and alleviate the effects of heavy metals on soybean cultivation in nickel mine soil, indicating a novel evidence for further exploring more functional microbes from the nickel mine soil.
矿区土壤不仅贫瘠，而且还受到一些重金属的污染。目前尚不清楚镍矿土壤中的某些根瘤菌是否能在极端条件下存活。因此，本研究试图从镍矿土壤中分离出一些具有促生和耐重金属特性的有效大豆根瘤菌，并分析其多样性。利用大豆植株从镍矿土壤中捕获根瘤菌。共初步鉴定出 21 株根瘤菌，采用 BOXA1R-PCR 指纹图谱技术在 87%相似性水平上将其聚类为 8 个组。在大豆盆栽试验中，8 个代表性分离株中的 4 个在大豆根上形成根瘤，具有有效的共生固氮和促生能力。16S rRNA、4 个看家基因（---）和基因的系统发育分析将共生分离株 YN5、YN8 和 YN10 分别归入和 YN11 归入 ，它们对包括镉、铬、铜、镍和锌在内的重金属也表现出不同的耐受水平。研究结果表明，镍矿土壤中存在一些具有促生和耐重金属特性的根瘤菌，具有促进植物修复和减轻重金属对大豆种植影响的潜力，为进一步从镍矿土壤中探索更多功能微生物提供了新的依据。
